WEBVTT Kind: captions Language: en 00:00:01.360 --> 00:00:03.630 align:start position:0% Time<00:00:01.720> moves<00:00:02.040> slower<00:00:02.560> on<00:00:02.760> Mercury<00:00:03.360> than<00:00:03.520> it 00:00:03.630 --> 00:00:03.640 align:start position:0% Time moves slower on Mercury than it 00:00:03.640 --> 00:00:06.110 align:start position:0% Time moves slower on Mercury than it does<00:00:04.040> on<00:00:04.240> Earth. 00:00:06.110 --> 00:00:06.120 align:start position:0% does on Earth. 00:00:06.120 --> 00:00:09.230 align:start position:0% does on Earth. A<00:00:06.200> day<00:00:06.440> on<00:00:06.600> Mercury<00:00:07.120> is<00:00:07.480> 58<00:00:08.040> days,<00:00:08.480> 15<00:00:08.920> hours, 00:00:09.230 --> 00:00:09.240 align:start position:0% A day on Mercury is 58 days, 15 hours, 00:00:09.240 --> 00:00:11.590 align:start position:0% A day on Mercury is 58 days, 15 hours, and<00:00:09.440> 30<00:00:09.760> minutes<00:00:10.040> on<00:00:10.240> Earth.<00:00:11.120> We<00:00:11.160> can<00:00:11.320> tell 00:00:11.590 --> 00:00:11.600 align:start position:0% and 30 minutes on Earth. We can tell 00:00:11.600 --> 00:00:13.470 align:start position:0% and 30 minutes on Earth. We can tell this<00:00:11.840> by<00:00:12.120> observing<00:00:12.720> Mercury<00:00:13.200> through 00:00:13.470 --> 00:00:13.480 align:start position:0% this by observing Mercury through 00:00:13.480 --> 00:00:15.390 align:start position:0% this by observing Mercury through telescopes<00:00:14.280> and<00:00:14.410> [music]<00:00:14.440> timing<00:00:14.880> how<00:00:15.080> long 00:00:15.390 --> 00:00:15.400 align:start position:0% telescopes and [music] timing how long 00:00:15.400 --> 00:00:17.230 align:start position:0% telescopes and [music] timing how long it<00:00:15.520> would<00:00:15.640> take<00:00:15.880> for<00:00:16.000> Mercury<00:00:16.560> to<00:00:16.720> complete 00:00:17.230 --> 00:00:17.240 align:start position:0% it would take for Mercury to complete 00:00:17.240 --> 00:00:20.470 align:start position:0% it would take for Mercury to complete one<00:00:17.520> full<00:00:17.880> orbit<00:00:18.320> around<00:00:18.640> the<00:00:18.720> Sun. 00:00:20.470 --> 00:00:20.480 align:start position:0% one full orbit around the Sun. 00:00:20.480 --> 00:00:23.110 align:start position:0% one full orbit around the Sun. However,<00:00:21.160> if<00:00:21.360> we<00:00:21.520> travel<00:00:22.200> to<00:00:22.320> Mercury<00:00:22.920> and 00:00:23.110 --> 00:00:23.120 align:start position:0% However, if we travel to Mercury and 00:00:23.120 --> 00:00:25.535 align:start position:0% However, if we travel to Mercury and started<00:00:23.520> our<00:00:23.720> timer<00:00:24.160> there,<00:00:25.080> we<00:00:25.240> would<00:00:25.480> not 00:00:25.535 --> 00:00:25.545 align:start position:0% started our timer there, we would not 00:00:25.545 --> 00:00:28.270 align:start position:0% started our timer there, we would not [music]<00:00:26.000> get<00:00:26.200> the<00:00:26.280> same<00:00:26.560> figure. 00:00:28.270 --> 00:00:28.280 align:start position:0% [music] get the same figure. 00:00:28.280 --> 00:00:30.270 align:start position:0% [music] get the same figure. This<00:00:28.400> is<00:00:28.520> because<00:00:29.000> time<00:00:29.320> does<00:00:29.480> not<00:00:29.880> move<00:00:30.160> as 00:00:30.270 --> 00:00:30.280 align:start position:0% This is because time does not move as 00:00:30.280 --> 00:00:32.630 align:start position:0% This is because time does not move as constantly<00:00:30.920> as<00:00:31.040> you<00:00:31.120> might<00:00:31.360> think. 00:00:32.630 --> 00:00:32.640 align:start position:0% constantly as you might think. 00:00:32.640 --> 00:00:35.190 align:start position:0% constantly as you might think. It<00:00:32.800> can<00:00:32.960> be<00:00:33.080> affected<00:00:33.520> by<00:00:33.680> speed.<00:00:34.680> The<00:00:34.800> faster 00:00:35.190 --> 00:00:35.200 align:start position:0% It can be affected by speed. The faster 00:00:35.200 --> 00:00:37.830 align:start position:0% It can be affected by speed. The faster you<00:00:35.360> go,<00:00:35.800> the<00:00:35.920> slower<00:00:36.320> time<00:00:36.600> goes<00:00:36.880> for<00:00:37.000> you. 00:00:37.830 --> 00:00:37.840 align:start position:0% you go, the slower time goes for you. 00:00:37.840 --> 00:00:40.870 align:start position:0% you go, the slower time goes for you. But,<00:00:37.920> it<00:00:38.040> can<00:00:38.240> also<00:00:38.640> be<00:00:38.800> affected<00:00:39.320> by<00:00:39.480> gravity. 00:00:40.870 --> 00:00:40.880 align:start position:0% But, it can also be affected by gravity. 00:00:40.880 --> 00:00:42.830 align:start position:0% But, it can also be affected by gravity. And<00:00:41.000> Mercury<00:00:41.520> is<00:00:41.760> much<00:00:42.160> closer<00:00:42.575> [music]<00:00:42.600> to<00:00:42.760> a 00:00:42.830 --> 00:00:42.840 align:start position:0% And Mercury is much closer [music] to a 00:00:42.840 --> 00:00:44.950 align:start position:0% And Mercury is much closer [music] to a massive<00:00:43.440> source<00:00:43.720> of<00:00:43.840> gravity<00:00:44.280> in<00:00:44.480> our<00:00:44.680> solar 00:00:44.950 --> 00:00:44.960 align:start position:0% massive source of gravity in our solar 00:00:44.960 --> 00:00:47.990 align:start position:0% massive source of gravity in our solar system,<00:00:45.800> the<00:00:45.960> Sun. 00:00:47.990 --> 00:00:48.000 align:start position:0% system, the Sun. 00:00:48.000 --> 00:00:50.910 align:start position:0% system, the Sun. But,<00:00:48.600> how<00:00:48.800> much<00:00:49.280> does<00:00:49.480> gravity<00:00:49.880> affect<00:00:50.200> time? 00:00:50.910 --> 00:00:50.920 align:start position:0% But, how much does gravity affect time? 00:00:50.920 --> 00:00:53.070 align:start position:0% But, how much does gravity affect time? Could<00:00:51.120> we<00:00:51.240> live<00:00:51.520> to<00:00:51.680> incredible<00:00:52.360> ages<00:00:52.800> if<00:00:52.920> we 00:00:53.070 --> 00:00:53.080 align:start position:0% Could we live to incredible ages if we 00:00:53.080 --> 00:00:56.030 align:start position:0% Could we live to incredible ages if we all<00:00:53.280> went<00:00:53.480> to<00:00:53.600> live<00:00:53.880> on<00:00:54.040> Mercury? 00:00:56.030 --> 00:00:56.040 align:start position:0% all went to live on Mercury? 00:00:56.040 --> 00:00:58.030 align:start position:0% all went to live on Mercury? I'm<00:00:56.240> Alex<00:00:56.520> McColluch,<00:00:57.120> and<00:00:57.480> you're<00:00:57.680> watching 00:00:58.030 --> 00:00:58.040 align:start position:0% I'm Alex McColluch, and you're watching 00:00:58.040 --> 00:01:00.470 align:start position:0% I'm Alex McColluch, and you're watching Astrium.<00:00:58.880> Join<00:00:59.120> with<00:00:59.280> me<00:00:59.400> today<00:00:59.800> as<00:01:00.000> we<00:01:00.160> answer 00:01:00.470 --> 00:01:00.480 align:start position:0% Astrium. Join with me today as we answer 00:01:00.480 --> 00:01:02.230 align:start position:0% Astrium. Join with me today as we answer this<00:01:00.680> question<00:01:01.520> and<00:01:01.600> explore<00:01:02.120> the<00:01:02.225> [music] 00:01:02.230 --> 00:01:02.240 align:start position:0% this question and explore the [music] 00:01:02.240 --> 00:01:04.710 align:start position:0% this question and explore the [music] strange<00:01:02.880> and<00:01:03.120> warping<00:01:03.600> world<00:01:04.040> of<00:01:04.239> general 00:01:04.710 --> 00:01:04.720 align:start position:0% strange and warping world of general 00:01:04.720 --> 00:01:07.110 align:start position:0% strange and warping world of general relativity<00:01:05.800> and<00:01:06.000> gravitational<00:01:06.800> time 00:01:07.110 --> 00:01:07.120 align:start position:0% relativity and gravitational time 00:01:07.120 --> 00:01:08.110 align:start position:0% relativity and gravitational time dilation. 00:01:08.110 --> 00:01:08.120 align:start position:0% dilation. 00:01:08.120 --> 00:01:08.430 align:start position:0% dilation. >> [music] 00:01:08.430 --> 00:01:08.440 align:start position:0% >> [music] 00:01:08.440 --> 00:01:10.110 align:start position:0% >> [music] >> I<00:01:08.560> hope<00:01:08.800> by<00:01:08.920> the<00:01:09.040> end<00:01:09.160> of<00:01:09.240> this<00:01:09.440> video<00:01:09.800> to<00:01:09.960> have 00:01:10.110 --> 00:01:10.120 align:start position:0% >> I hope by the end of this video to have 00:01:10.120 --> 00:01:14.390 align:start position:0% >> I hope by the end of this video to have earned<00:01:10.360> your<00:01:10.520> like<00:01:10.880> and<00:01:11.000> subscription. 00:01:14.390 --> 00:01:14.400 align:start position:0% 00:01:14.400 --> 00:01:18.590 align:start position:0% To<00:01:14.520> begin<00:01:14.840> with,<00:01:15.440> what<00:01:15.800> exactly<00:01:16.600> is<00:01:16.960> time? 00:01:18.590 --> 00:01:18.600 align:start position:0% To begin with, what exactly is time? 00:01:18.600 --> 00:01:20.510 align:start position:0% To begin with, what exactly is time? Mark<00:01:18.800> Twain<00:01:19.160> once<00:01:19.400> said<00:01:19.640> that<00:01:19.800> time<00:01:20.160> is<00:01:20.360> what 00:01:20.510 --> 00:01:20.520 align:start position:0% Mark Twain once said that time is what 00:01:20.520 --> 00:01:22.430 align:start position:0% Mark Twain once said that time is what keeps<00:01:20.840> everything<00:01:21.360> from<00:01:21.560> happening<00:01:22.080> all<00:01:22.320> at 00:01:22.430 --> 00:01:22.440 align:start position:0% keeps everything from happening all at 00:01:22.440 --> 00:01:23.590 align:start position:0% keeps everything from happening all at once.<00:01:22.530> [music] 00:01:23.590 --> 00:01:23.600 align:start position:0% once. [music] 00:01:23.600 --> 00:01:25.350 align:start position:0% once. [music] It<00:01:23.720> separates<00:01:24.280> yesterday's<00:01:24.840> events<00:01:25.200> from 00:01:25.350 --> 00:01:25.360 align:start position:0% It separates yesterday's events from 00:01:25.360 --> 00:01:28.270 align:start position:0% It separates yesterday's events from today's<00:01:26.120> and<00:01:26.280> today's<00:01:26.760> from<00:01:26.960> tomorrow's. 00:01:28.270 --> 00:01:28.280 align:start position:0% today's and today's from tomorrow's. 00:01:28.280 --> 00:01:30.550 align:start position:0% today's and today's from tomorrow's. As<00:01:28.480> you<00:01:28.600> sit<00:01:28.920> here<00:01:29.200> and<00:01:29.360> watch<00:01:29.600> this<00:01:29.800> video, 00:01:30.550 --> 00:01:30.560 align:start position:0% As you sit here and watch this video, 00:01:30.560 --> 00:01:32.110 align:start position:0% As you sit here and watch this video, you<00:01:30.760> are<00:01:30.880> not<00:01:31.160> doing<00:01:31.440> what<00:01:31.640> you<00:01:31.760> were<00:01:31.840> doing 00:01:32.110 --> 00:01:32.120 align:start position:0% you are not doing what you were doing 00:01:32.120 --> 00:01:34.310 align:start position:0% you are not doing what you were doing yesterday<00:01:32.800> or<00:01:32.960> tomorrow.<00:01:33.800> You<00:01:33.920> are<00:01:34.000> watching 00:01:34.310 --> 00:01:34.320 align:start position:0% yesterday or tomorrow. You are watching 00:01:34.320 --> 00:01:35.550 align:start position:0% yesterday or tomorrow. You are watching this<00:01:34.480> video. 00:01:35.550 --> 00:01:35.560 align:start position:0% this video. 00:01:35.560 --> 00:01:37.270 align:start position:0% this video. You<00:01:35.680> are<00:01:35.800> constantly<00:01:36.480> traveling<00:01:37.000> through 00:01:37.270 --> 00:01:37.280 align:start position:0% You are constantly traveling through 00:01:37.280 --> 00:01:39.910 align:start position:0% You are constantly traveling through time<00:01:37.760> in<00:01:37.880> the<00:01:38.000> direction<00:01:38.640> of<00:01:38.880> the<00:01:39.000> future<00:01:39.800> at 00:01:39.910 --> 00:01:39.920 align:start position:0% time in the direction of the future at 00:01:39.920 --> 00:01:42.710 align:start position:0% time in the direction of the future at the<00:01:40.000> rate<00:01:40.216> [music]<00:01:40.240> of<00:01:40.520> 1<00:01:40.800> second<00:01:41.320> per<00:01:41.480> second. 00:01:42.710 --> 00:01:42.720 align:start position:0% the rate [music] of 1 second per second. 00:01:42.720 --> 00:01:44.310 align:start position:0% the rate [music] of 1 second per second. This<00:01:42.880> is<00:01:43.000> the<00:01:43.120> normal<00:01:43.440> speed<00:01:43.800> for<00:01:43.920> traveling 00:01:44.310 --> 00:01:44.320 align:start position:0% This is the normal speed for traveling 00:01:44.320 --> 00:01:46.590 align:start position:0% This is the normal speed for traveling through<00:01:44.520> time<00:01:45.080> and<00:01:45.200> is<00:01:45.320> shared<00:01:45.600> by<00:01:45.840> you<00:01:46.240> and 00:01:46.590 --> 00:01:46.600 align:start position:0% through time and is shared by you and 00:01:46.600 --> 00:01:48.590 align:start position:0% through time and is shared by you and everyone<00:01:47.040> else<00:01:47.280> on<00:01:47.400> the<00:01:47.480> planet. 00:01:48.590 --> 00:01:48.600 align:start position:0% everyone else on the planet. 00:01:48.600 --> 00:01:50.710 align:start position:0% everyone else on the planet. But,<00:01:48.960> this<00:01:49.240> speed<00:01:49.640> doesn't<00:01:50.040> have<00:01:50.360> to<00:01:50.480> be<00:01:50.600> the 00:01:50.710 --> 00:01:50.720 align:start position:0% But, this speed doesn't have to be the 00:01:50.720 --> 00:01:52.670 align:start position:0% But, this speed doesn't have to be the case. 00:01:52.670 --> 00:01:52.680 align:start position:0% case. 00:01:52.680 --> 00:01:54.790 align:start position:0% case. As<00:01:52.840> discovered<00:01:53.280> by<00:01:53.480> Albert<00:01:53.880> Einstein,<00:01:54.680> the 00:01:54.790 --> 00:01:54.800 align:start position:0% As discovered by Albert Einstein, the 00:01:54.800 --> 00:01:56.750 align:start position:0% As discovered by Albert Einstein, the faster<00:01:55.200> we<00:01:55.320> travel<00:01:55.720> through<00:01:55.960> space,<00:01:56.600> the 00:01:56.750 --> 00:01:56.760 align:start position:0% faster we travel through space, the 00:01:56.760 --> 00:01:59.150 align:start position:0% faster we travel through space, the slower<00:01:57.440> our<00:01:57.640> time<00:01:57.960> becomes. 00:01:59.150 --> 00:01:59.160 align:start position:0% slower our time becomes. 00:01:59.160 --> 00:02:01.390 align:start position:0% slower our time becomes. Up<00:01:59.360> until<00:01:59.640> the<00:01:59.760> point<00:02:00.160> where<00:02:00.440> if<00:02:00.640> we<00:02:00.800> somehow 00:02:01.390 --> 00:02:01.400 align:start position:0% Up until the point where if we somehow 00:02:01.400 --> 00:02:03.710 align:start position:0% Up until the point where if we somehow could<00:02:01.600> travel<00:02:02.000> at<00:02:02.080> the<00:02:02.160> speed<00:02:02.520> of<00:02:02.640> light,<00:02:03.400> time 00:02:03.710 --> 00:02:03.720 align:start position:0% could travel at the speed of light, time 00:02:03.720 --> 00:02:06.550 align:start position:0% could travel at the speed of light, time would<00:02:03.880> stop<00:02:04.360> moving<00:02:04.800> for<00:02:05.080> us. 00:02:06.550 --> 00:02:06.560 align:start position:0% would stop moving for us. 00:02:06.560 --> 00:02:08.510 align:start position:0% would stop moving for us. If<00:02:06.680> we<00:02:06.840> were<00:02:06.960> to<00:02:07.080> travel<00:02:07.440> to<00:02:07.560> an<00:02:07.720> object<00:02:08.240> four 00:02:08.510 --> 00:02:08.520 align:start position:0% If we were to travel to an object four 00:02:08.520 --> 00:02:10.710 align:start position:0% If we were to travel to an object four light-years<00:02:09.000> away<00:02:09.200> from<00:02:09.440> us,<00:02:10.039> to<00:02:10.119> people<00:02:10.479> here 00:02:10.710 --> 00:02:10.720 align:start position:0% light-years away from us, to people here 00:02:10.720 --> 00:02:12.270 align:start position:0% light-years away from us, to people here on<00:02:10.880> Earth,<00:02:11.200> it<00:02:11.320> would<00:02:11.440> look<00:02:11.600> like<00:02:11.760> it<00:02:11.880> took<00:02:12.080> us 00:02:12.270 --> 00:02:12.280 align:start position:0% on Earth, it would look like it took us 00:02:12.280 --> 00:02:13.710 align:start position:0% on Earth, it would look like it took us four<00:02:12.680> years. 00:02:13.710 --> 00:02:13.720 align:start position:0% four years. 00:02:13.720 --> 00:02:16.230 align:start position:0% four years. To<00:02:14.000> us,<00:02:14.760> it<00:02:14.880> would<00:02:15.040> look<00:02:15.240> like<00:02:15.480> we<00:02:15.600> arrived<00:02:16.080> at 00:02:16.230 --> 00:02:16.240 align:start position:0% To us, it would look like we arrived at 00:02:16.240 --> 00:02:19.630 align:start position:0% To us, it would look like we arrived at our<00:02:16.400> destination<00:02:17.360> instantaneously. 00:02:19.630 --> 00:02:19.640 align:start position:0% our destination instantaneously. 00:02:19.640 --> 00:02:21.590 align:start position:0% our destination instantaneously. Although<00:02:19.920> this<00:02:20.080> sounds<00:02:20.560> incredible, 00:02:21.590 --> 00:02:21.600 align:start position:0% Although this sounds incredible, 00:02:21.600 --> 00:02:23.310 align:start position:0% Although this sounds incredible, scientists<00:02:22.120> have<00:02:22.280> proven<00:02:22.760> that<00:02:22.959> this 00:02:23.310 --> 00:02:23.320 align:start position:0% scientists have proven that this 00:02:23.320 --> 00:02:24.990 align:start position:0% scientists have proven that this actually<00:02:23.800> happens. 00:02:24.990 --> 00:02:25.000 align:start position:0% actually happens. 00:02:25.000 --> 00:02:27.590 align:start position:0% actually happens. They<00:02:25.120> took<00:02:25.400> two<00:02:25.640> clocks.<00:02:26.560> One<00:02:26.920> they<00:02:27.200> put<00:02:27.440> on<00:02:27.560> a 00:02:27.590 --> 00:02:27.600 align:start position:0% They took two clocks. One they put on a 00:02:27.600 --> 00:02:29.550 align:start position:0% They took two clocks. One they put on a plane<00:02:28.080> and<00:02:28.360> flew<00:02:28.560> around<00:02:28.920> the<00:02:29.000> world<00:02:29.280> with<00:02:29.440> it 00:02:29.550 --> 00:02:29.560 align:start position:0% plane and flew around the world with it 00:02:29.560 --> 00:02:31.670 align:start position:0% plane and flew around the world with it on<00:02:29.720> board,<00:02:30.400> increasing<00:02:30.959> its<00:02:31.120> speed<00:02:31.520> for<00:02:31.600> an 00:02:31.670 --> 00:02:31.680 align:start position:0% on board, increasing its speed for an 00:02:31.680 --> 00:02:33.830 align:start position:0% on board, increasing its speed for an extended<00:02:32.160> amount<00:02:32.440> of<00:02:32.560> time,<00:02:33.320> while<00:02:33.480> leaving 00:02:33.830 --> 00:02:33.840 align:start position:0% extended amount of time, while leaving 00:02:33.840 --> 00:02:36.510 align:start position:0% extended amount of time, while leaving the<00:02:34.040> other<00:02:34.400> at<00:02:34.560> a<00:02:34.600> stationary<00:02:35.280> location. 00:02:36.510 --> 00:02:36.520 align:start position:0% the other at a stationary location. 00:02:36.520 --> 00:02:38.070 align:start position:0% the other at a stationary location. When<00:02:36.680> they<00:02:36.800> eventually<00:02:37.280> returned<00:02:37.959> and 00:02:38.070 --> 00:02:38.080 align:start position:0% When they eventually returned and 00:02:38.080 --> 00:02:40.030 align:start position:0% When they eventually returned and compared<00:02:38.440> the<00:02:38.560> clocks<00:02:38.880> again,<00:02:39.600> they<00:02:39.720> found 00:02:40.030 --> 00:02:40.040 align:start position:0% compared the clocks again, they found 00:02:40.040 --> 00:02:42.110 align:start position:0% compared the clocks again, they found that<00:02:40.160> the<00:02:40.280> clock<00:02:40.720> that<00:02:40.880> had<00:02:41.000> traveled<00:02:41.360> faster 00:02:42.110 --> 00:02:42.120 align:start position:0% that the clock that had traveled faster 00:02:42.120 --> 00:02:45.070 align:start position:0% that the clock that had traveled faster had<00:02:42.400> actually<00:02:42.880> recorded<00:02:43.520> less<00:02:43.880> time,<00:02:44.640> in<00:02:44.800> line 00:02:45.070 --> 00:02:45.080 align:start position:0% had actually recorded less time, in line 00:02:45.080 --> 00:02:46.670 align:start position:0% had actually recorded less time, in line with<00:02:45.280> what<00:02:45.520> general<00:02:45.880> relativity<00:02:46.520> had 00:02:46.670 --> 00:02:46.680 align:start position:0% with what general relativity had 00:02:46.680 --> 00:02:47.870 align:start position:0% with what general relativity had predicted. 00:02:47.870 --> 00:02:47.880 align:start position:0% predicted. 00:02:47.880 --> 00:02:51.750 align:start position:0% predicted. General<00:02:48.240> relativity<00:02:49.160> is<00:02:49.320> a<00:02:49.400> real<00:02:49.760> thing. 00:02:51.750 --> 00:02:51.760 align:start position:0% General relativity is a real thing. 00:02:51.760 --> 00:02:53.470 align:start position:0% General relativity is a real thing. But<00:02:51.959> Einstein<00:02:52.400> also<00:02:52.760> predicted<00:02:53.200> that<00:02:53.320> this 00:02:53.470 --> 00:02:53.480 align:start position:0% But Einstein also predicted that this 00:02:53.480 --> 00:02:55.949 align:start position:0% But Einstein also predicted that this would<00:02:53.640> happen<00:02:53.959> with<00:02:54.160> gravity. 00:02:55.949 --> 00:02:55.959 align:start position:0% would happen with gravity. 00:02:55.959 --> 00:02:57.830 align:start position:0% would happen with gravity. The<00:02:56.040> closer<00:02:56.400> you<00:02:56.600> are<00:02:56.840> to<00:02:57.000> a<00:02:57.080> large<00:02:57.480> source<00:02:57.720> of 00:02:57.830 --> 00:02:57.840 align:start position:0% The closer you are to a large source of 00:02:57.840 --> 00:03:00.030 align:start position:0% The closer you are to a large source of gravity,<00:02:58.760> and<00:02:58.880> the<00:02:58.959> more<00:02:59.239> mass<00:02:59.600> that<00:02:59.800> source 00:03:00.030 --> 00:03:00.040 align:start position:0% gravity, and the more mass that source 00:03:00.040 --> 00:03:02.870 align:start position:0% gravity, and the more mass that source of<00:03:00.160> gravity<00:03:00.600> has,<00:03:01.480> the<00:03:01.600> slower<00:03:02.080> time<00:03:02.519> will<00:03:02.680> go 00:03:02.870 --> 00:03:02.880 align:start position:0% of gravity has, the slower time will go 00:03:02.880 --> 00:03:04.229 align:start position:0% of gravity has, the slower time will go for<00:03:03.040> you. 00:03:04.229 --> 00:03:04.239 align:start position:0% for you. 00:03:04.239 --> 00:03:06.710 align:start position:0% for you. This<00:03:04.440> was<00:03:04.600> proven<00:03:04.959> to<00:03:05.040> be<00:03:05.160> correct<00:03:05.560> in<00:03:05.680> 1959 00:03:06.710 --> 00:03:06.720 align:start position:0% This was proven to be correct in 1959 00:03:06.720 --> 00:03:09.030 align:start position:0% This was proven to be correct in 1959 with<00:03:06.880> the<00:03:06.959> Pound-Rebka<00:03:07.760> experiment,<00:03:08.880> where 00:03:09.030 --> 00:03:09.040 align:start position:0% with the Pound-Rebka experiment, where 00:03:09.040 --> 00:03:10.790 align:start position:0% with the Pound-Rebka experiment, where they<00:03:09.160> shot<00:03:09.519> gamma<00:03:09.800> rays<00:03:10.120> from<00:03:10.280> the<00:03:10.400> top<00:03:10.640> of<00:03:10.760> a 00:03:10.790 --> 00:03:10.800 align:start position:0% they shot gamma rays from the top of a 00:03:10.800 --> 00:03:13.270 align:start position:0% they shot gamma rays from the top of a tall<00:03:11.160> building<00:03:11.640> to<00:03:11.760> the<00:03:11.840> bottom<00:03:12.680> and<00:03:12.800> recorded 00:03:13.270 --> 00:03:13.280 align:start position:0% tall building to the bottom and recorded 00:03:13.280 --> 00:03:14.710 align:start position:0% tall building to the bottom and recorded whether<00:03:13.560> anything<00:03:14.000> had<00:03:14.160> happened<00:03:14.519> to<00:03:14.600> the 00:03:14.710 --> 00:03:14.720 align:start position:0% whether anything had happened to the 00:03:14.720 --> 00:03:16.030 align:start position:0% whether anything had happened to the light<00:03:14.959> waves. 00:03:16.030 --> 00:03:16.040 align:start position:0% light waves. 00:03:16.040 --> 00:03:17.750 align:start position:0% light waves. They<00:03:16.160> found<00:03:16.680> that<00:03:16.840> the<00:03:16.959> frequency<00:03:17.560> of<00:03:17.680> the 00:03:17.750 --> 00:03:17.760 align:start position:0% They found that the frequency of the 00:03:17.760 --> 00:03:19.670 align:start position:0% They found that the frequency of the waves<00:03:18.120> increased<00:03:18.800> the<00:03:18.920> closer<00:03:19.239> to<00:03:19.360> the<00:03:19.519> Earth 00:03:19.670 --> 00:03:19.680 align:start position:0% waves increased the closer to the Earth 00:03:19.680 --> 00:03:22.030 align:start position:0% waves increased the closer to the Earth they<00:03:19.840> were.<00:03:20.519> Kind<00:03:20.720> of<00:03:20.800> like<00:03:21.040> cars<00:03:21.440> bunching<00:03:21.840> up 00:03:22.030 --> 00:03:22.040 align:start position:0% they were. Kind of like cars bunching up 00:03:22.040 --> 00:03:24.070 align:start position:0% they were. Kind of like cars bunching up in<00:03:22.239> congested<00:03:22.760> traffic,<00:03:23.680> the<00:03:23.707> [music]<00:03:23.800> peaks 00:03:24.070 --> 00:03:24.080 align:start position:0% in congested traffic, the [music] peaks 00:03:24.080 --> 00:03:26.630 align:start position:0% in congested traffic, the [music] peaks of<00:03:24.239> radiation<00:03:25.000> moved<00:03:25.200> closer<00:03:25.560> together. 00:03:26.630 --> 00:03:26.640 align:start position:0% of radiation moved closer together. 00:03:26.640 --> 00:03:28.710 align:start position:0% of radiation moved closer together. Time<00:03:26.959> slowed<00:03:27.280> down<00:03:27.760> ever<00:03:28.000> so<00:03:28.160> slightly<00:03:28.600> for 00:03:28.710 --> 00:03:28.720 align:start position:0% Time slowed down ever so slightly for 00:03:28.720 --> 00:03:30.670 align:start position:0% Time slowed down ever so slightly for the<00:03:28.840> gamma<00:03:29.120> radiation,<00:03:29.800> the<00:03:29.920> closer<00:03:30.280> it<00:03:30.400> got 00:03:30.670 --> 00:03:30.680 align:start position:0% the gamma radiation, the closer it got 00:03:30.680 --> 00:03:32.470 align:start position:0% the gamma radiation, the closer it got to<00:03:30.760> the<00:03:30.959> Earth. 00:03:32.470 --> 00:03:32.480 align:start position:0% to the Earth. 00:03:32.480 --> 00:03:34.630 align:start position:0% to the Earth. This<00:03:32.640> effect<00:03:33.160> is<00:03:33.320> significant<00:03:34.080> enough<00:03:34.440> that 00:03:34.630 --> 00:03:34.640 align:start position:0% This effect is significant enough that 00:03:34.640 --> 00:03:36.310 align:start position:0% This effect is significant enough that satellites<00:03:35.200> have<00:03:35.440> to<00:03:35.519> be<00:03:35.640> programmed<00:03:36.200> to 00:03:36.310 --> 00:03:36.320 align:start position:0% satellites have to be programmed to 00:03:36.320 --> 00:03:38.190 align:start position:0% satellites have to be programmed to account<00:03:36.640> for<00:03:36.800> it,<00:03:37.440> because<00:03:37.760> when<00:03:37.959> they<00:03:38.080> are 00:03:38.190 --> 00:03:38.200 align:start position:0% account for it, because when they are 00:03:38.200 --> 00:03:40.229 align:start position:0% account for it, because when they are further<00:03:38.600> away<00:03:38.880> from<00:03:39.080> the<00:03:39.200> Earth's<00:03:39.440> gravity, 00:03:40.229 --> 00:03:40.239 align:start position:0% further away from the Earth's gravity, 00:03:40.239 --> 00:03:42.509 align:start position:0% further away from the Earth's gravity, time<00:03:40.519> moves<00:03:40.840> more<00:03:41.000> quickly<00:03:41.400> for<00:03:41.600> them. 00:03:42.509 --> 00:03:42.519 align:start position:0% time moves more quickly for them. 00:03:42.519 --> 00:03:44.350 align:start position:0% time moves more quickly for them. Without<00:03:42.880> this<00:03:43.040> correction,<00:03:43.840> their<00:03:43.959> internal 00:03:44.350 --> 00:03:44.360 align:start position:0% Without this correction, their internal 00:03:44.360 --> 00:03:46.229 align:start position:0% Without this correction, their internal clocks<00:03:44.720> would<00:03:44.880> go<00:03:45.160> out<00:03:45.360> of<00:03:45.480> sync<00:03:45.760> with<00:03:46.000> our 00:03:46.229 --> 00:03:46.239 align:start position:0% clocks would go out of sync with our 00:03:46.239 --> 00:03:47.910 align:start position:0% clocks would go out of sync with our clocks<00:03:46.560> on<00:03:46.720> Earth,<00:03:47.280> which<00:03:47.480> would<00:03:47.600> cause 00:03:47.910 --> 00:03:47.920 align:start position:0% clocks on Earth, which would cause 00:03:47.920 --> 00:03:49.390 align:start position:0% clocks on Earth, which would cause problems. 00:03:49.390 --> 00:03:49.400 align:start position:0% problems. 00:03:49.400 --> 00:03:51.470 align:start position:0% problems. And<00:03:49.560> yes,<00:03:50.040> that's<00:03:50.320> right.<00:03:51.040> The<00:03:51.200> Earth's 00:03:51.470 --> 00:03:51.480 align:start position:0% And yes, that's right. The Earth's 00:03:51.480 --> 00:03:54.030 align:start position:0% And yes, that's right. The Earth's gravity<00:03:52.040> is<00:03:52.320> enough<00:03:52.800> to<00:03:52.920> cause<00:03:53.240> time<00:03:53.600> to<00:03:53.720> slow 00:03:54.030 --> 00:03:54.040 align:start position:0% gravity is enough to cause time to slow 00:03:54.040 --> 00:03:55.750 align:start position:0% gravity is enough to cause time to slow down<00:03:54.360> for<00:03:54.560> us. 00:03:55.750 --> 00:03:55.760 align:start position:0% down for us. 00:03:55.760 --> 00:03:58.190 align:start position:0% down for us. So,<00:03:56.120> you're<00:03:56.400> probably<00:03:56.920> now<00:03:57.160> thinking,<00:03:57.960> "How 00:03:58.190 --> 00:03:58.200 align:start position:0% So, you're probably now thinking, "How 00:03:58.200 --> 00:04:00.110 align:start position:0% So, you're probably now thinking, "How much<00:03:58.560> faster<00:03:58.960> would<00:03:59.080> time<00:03:59.360> be<00:03:59.480> going<00:03:59.760> for<00:03:59.880> me 00:04:00.110 --> 00:04:00.120 align:start position:0% much faster would time be going for me 00:04:00.120 --> 00:04:02.310 align:start position:0% much faster would time be going for me if<00:04:00.360> I<00:04:00.440> wasn't<00:04:00.760> on<00:04:00.960> Earth<00:04:01.320> or<00:04:01.600> if<00:04:01.800> Earth<00:04:02.040> had<00:04:02.160> no 00:04:02.310 --> 00:04:02.320 align:start position:0% if I wasn't on Earth or if Earth had no 00:04:02.320 --> 00:04:04.110 align:start position:0% if I wasn't on Earth or if Earth had no gravity?" 00:04:04.110 --> 00:04:04.120 align:start position:0% gravity?" 00:04:04.120 --> 00:04:06.790 align:start position:0% gravity?" Well,<00:04:04.480> it's<00:04:04.720> a<00:04:04.760> matter<00:04:05.120> of<00:04:05.240> perspective.<00:04:06.680> The 00:04:06.790 --> 00:04:06.800 align:start position:0% Well, it's a matter of perspective. The 00:04:06.800 --> 00:04:08.350 align:start position:0% Well, it's a matter of perspective. The procession<00:04:07.280> of<00:04:07.360> time<00:04:07.600> will<00:04:07.800> always<00:04:08.080> appear 00:04:08.350 --> 00:04:08.360 align:start position:0% procession of time will always appear 00:04:08.360 --> 00:04:10.390 align:start position:0% procession of time will always appear the<00:04:08.440> same<00:04:08.720> from<00:04:08.920> your<00:04:09.160> perspective.<00:04:10.240> You 00:04:10.390 --> 00:04:10.400 align:start position:0% the same from your perspective. You 00:04:10.400 --> 00:04:12.167 align:start position:0% the same from your perspective. You won't<00:04:10.720> feel<00:04:11.120> like<00:04:11.400> you're<00:04:11.520> going<00:04:11.800> slower, 00:04:12.167 --> 00:04:12.177 align:start position:0% won't feel like you're going slower, 00:04:12.177 --> 00:04:13.870 align:start position:0% won't feel like you're going slower, [music]<00:04:12.680> although<00:04:12.920> you<00:04:13.040> may<00:04:13.320> notice<00:04:13.680> some 00:04:13.870 --> 00:04:13.880 align:start position:0% [music] although you may notice some 00:04:13.880 --> 00:04:16.030 align:start position:0% [music] although you may notice some weird<00:04:14.200> stuff<00:04:14.480> going<00:04:14.720> on<00:04:14.840> around<00:04:15.200> you. 00:04:16.030 --> 00:04:16.040 align:start position:0% weird stuff going on around you. 00:04:16.040 --> 00:04:17.430 align:start position:0% weird stuff going on around you. But,<00:04:16.160> it's<00:04:16.320> the<00:04:16.519> outside<00:04:17.040> observer<00:04:17.417> [music] 00:04:17.430 --> 00:04:17.440 align:start position:0% But, it's the outside observer [music] 00:04:17.440 --> 00:04:20.509 align:start position:0% But, it's the outside observer [music] that<00:04:17.680> has<00:04:17.840> to<00:04:17.959> deal<00:04:18.280> with<00:04:18.480> you<00:04:18.600> slowing<00:04:18.959> down. 00:04:20.509 --> 00:04:20.519 align:start position:0% that has to deal with you slowing down. 00:04:20.519 --> 00:04:22.390 align:start position:0% that has to deal with you slowing down. To<00:04:20.720> find<00:04:21.040> out<00:04:21.280> an<00:04:21.359> exact<00:04:21.920> answer<00:04:22.200> to<00:04:22.320> the 00:04:22.390 --> 00:04:22.400 align:start position:0% To find out an exact answer to the 00:04:22.400 --> 00:04:24.613 align:start position:0% To find out an exact answer to the question,<00:04:23.200> Einstein<00:04:23.680> devised<00:04:24.200> the<00:04:24.320> following 00:04:24.613 --> 00:04:24.623 align:start position:0% question, Einstein devised the following 00:04:24.623 --> 00:04:27.110 align:start position:0% question, Einstein devised the following [music]<00:04:24.800> equation. 00:04:27.110 --> 00:04:27.120 align:start position:0% [music] equation. 00:04:27.120 --> 00:04:28.830 align:start position:0% [music] equation. We<00:04:27.320> will<00:04:27.440> be<00:04:27.560> using<00:04:27.840> this<00:04:27.960> equation<00:04:28.360> a<00:04:28.440> lot<00:04:28.760> in 00:04:28.830 --> 00:04:28.840 align:start position:0% We will be using this equation a lot in 00:04:28.840 --> 00:04:30.470 align:start position:0% We will be using this equation a lot in the<00:04:28.919> rest<00:04:29.160> of<00:04:29.240> the<00:04:29.320> video,<00:04:29.760> so<00:04:29.960> let's<00:04:30.200> try<00:04:30.360> to 00:04:30.470 --> 00:04:30.480 align:start position:0% the rest of the video, so let's try to 00:04:30.480 --> 00:04:31.830 align:start position:0% the rest of the video, so let's try to understand<00:04:31.000> it. 00:04:31.830 --> 00:04:31.840 align:start position:0% understand it. 00:04:31.840 --> 00:04:33.710 align:start position:0% understand it. It<00:04:32.000> looks<00:04:32.160> a<00:04:32.240> little<00:04:32.480> scary,<00:04:32.960> but<00:04:33.160> it's<00:04:33.280> not<00:04:33.600> as 00:04:33.710 --> 00:04:33.720 align:start position:0% It looks a little scary, but it's not as 00:04:33.720 --> 00:04:35.790 align:start position:0% It looks a little scary, but it's not as bad<00:04:33.960> as<00:04:34.080> it<00:04:34.200> looks. 00:04:35.790 --> 00:04:35.800 align:start position:0% bad as it looks. 00:04:35.800 --> 00:04:38.590 align:start position:0% bad as it looks. T0<00:04:36.800> is<00:04:37.000> the<00:04:37.120> answer<00:04:37.400> we're<00:04:37.520> looking<00:04:37.840> for,<00:04:38.480> how 00:04:38.590 --> 00:04:38.600 align:start position:0% T0 is the answer we're looking for, how 00:04:38.600 --> 00:04:40.470 align:start position:0% T0 is the answer we're looking for, how much<00:04:38.840> time<00:04:39.120> would<00:04:39.280> pass<00:04:39.640> on<00:04:39.760> the<00:04:39.880> object<00:04:40.320> we're 00:04:40.470 --> 00:04:40.480 align:start position:0% much time would pass on the object we're 00:04:40.480 --> 00:04:43.550 align:start position:0% much time would pass on the object we're interested<00:04:41.000> in,<00:04:41.520> in<00:04:41.640> this<00:04:41.800> case,<00:04:42.160> the<00:04:42.360> Earth. 00:04:43.550 --> 00:04:43.560 align:start position:0% interested in, in this case, the Earth. 00:04:43.560 --> 00:04:45.950 align:start position:0% interested in, in this case, the Earth. TF<00:04:44.440> is<00:04:44.680> how<00:04:44.800> much<00:04:45.040> time<00:04:45.320> would<00:04:45.480> pass<00:04:45.800> in<00:04:45.919> a 00:04:45.950 --> 00:04:45.960 align:start position:0% TF is how much time would pass in a 00:04:45.960 --> 00:04:48.510 align:start position:0% TF is how much time would pass in a place<00:04:46.320> completely<00:04:46.800> unaffected<00:04:47.320> by<00:04:47.440> gravity. 00:04:48.510 --> 00:04:48.520 align:start position:0% place completely unaffected by gravity. 00:04:48.520 --> 00:04:50.190 align:start position:0% place completely unaffected by gravity. Such<00:04:48.800> a<00:04:48.840> place<00:04:49.240> doesn't<00:04:49.513> [music]<00:04:49.560> exist,<00:04:50.080> by 00:04:50.190 --> 00:04:50.200 align:start position:0% Such a place doesn't [music] exist, by 00:04:50.200 --> 00:04:52.750 align:start position:0% Such a place doesn't [music] exist, by the<00:04:50.320> way,<00:04:51.000> but<00:04:51.320> it<00:04:51.480> is<00:04:51.720> our<00:04:51.919> hypothetical 00:04:52.750 --> 00:04:52.760 align:start position:0% the way, but it is our hypothetical 00:04:52.760 --> 00:04:54.870 align:start position:0% the way, but it is our hypothetical stationary<00:04:53.320> clock. 00:04:54.870 --> 00:04:54.880 align:start position:0% stationary clock. 00:04:54.880 --> 00:04:57.470 align:start position:0% stationary clock. G<00:04:55.400> is<00:04:55.760> the<00:04:55.840> gravitational<00:04:56.560> constant,<00:04:57.400> a 00:04:57.470 --> 00:04:57.480 align:start position:0% G is the gravitational constant, a 00:04:57.480 --> 00:04:59.270 align:start position:0% G is the gravitational constant, a number<00:04:57.760> they<00:04:57.919> added<00:04:58.280> to<00:04:58.400> basically<00:04:58.919> make<00:04:59.200> the 00:04:59.270 --> 00:04:59.280 align:start position:0% number they added to basically make the 00:04:59.280 --> 00:05:01.630 align:start position:0% number they added to basically make the sums<00:04:59.600> work<00:04:59.880> out.<00:05:00.640> We're<00:05:00.800> not<00:05:01.040> going<00:05:01.320> to<00:05:01.440> worry 00:05:01.630 --> 00:05:01.640 align:start position:0% sums work out. We're not going to worry 00:05:01.640 --> 00:05:03.470 align:start position:0% sums work out. We're not going to worry about<00:05:01.919> where<00:05:02.080> it<00:05:02.200> came<00:05:02.440> from.<00:05:03.120> All<00:05:03.320> we're 00:05:03.470 --> 00:05:03.480 align:start position:0% about where it came from. All we're 00:05:03.480 --> 00:05:05.670 align:start position:0% about where it came from. All we're interested<00:05:03.960> in<00:05:04.240> is<00:05:04.440> the<00:05:04.520> fact<00:05:04.960> it's<00:05:05.200> always 00:05:05.670 --> 00:05:05.680 align:start position:0% interested in is the fact it's always 00:05:05.680 --> 00:05:07.190 align:start position:0% interested in is the fact it's always this. 00:05:07.190 --> 00:05:07.200 align:start position:0% this. 00:05:07.200 --> 00:05:08.510 align:start position:0% this. And<00:05:07.360> don't<00:05:07.560> worry<00:05:07.760> too<00:05:07.880> much<00:05:08.120> about<00:05:08.360> that 00:05:08.510 --> 00:05:08.520 align:start position:0% And don't worry too much about that 00:05:08.520 --> 00:05:10.710 align:start position:0% And don't worry too much about that metric<00:05:08.919> at<00:05:09.000> the<00:05:09.120> end. 00:05:10.710 --> 00:05:10.720 align:start position:0% metric at the end. 00:05:10.720 --> 00:05:13.830 align:start position:0% metric at the end. M<00:05:11.280> is<00:05:11.600> mass,<00:05:12.360> specifically<00:05:13.080> the<00:05:13.200> mass<00:05:13.560> of<00:05:13.680> the 00:05:13.830 --> 00:05:13.840 align:start position:0% M is mass, specifically the mass of the 00:05:13.840 --> 00:05:16.150 align:start position:0% M is mass, specifically the mass of the object<00:05:14.320> creating<00:05:14.760> the<00:05:14.840> gravity. 00:05:16.150 --> 00:05:16.160 align:start position:0% object creating the gravity. 00:05:16.160 --> 00:05:18.230 align:start position:0% object creating the gravity. R<00:05:16.520> is<00:05:16.800> the<00:05:16.919> distance<00:05:17.440> from<00:05:17.560> the<00:05:17.640> center<00:05:18.000> of<00:05:18.080> the 00:05:18.230 --> 00:05:18.240 align:start position:0% R is the distance from the center of the 00:05:18.240 --> 00:05:21.470 align:start position:0% R is the distance from the center of the object,<00:05:19.040> and<00:05:19.320> C<00:05:19.840> is<00:05:20.040> the<00:05:20.160> speed<00:05:20.520> of<00:05:20.640> light,<00:05:21.400> a 00:05:21.470 --> 00:05:21.480 align:start position:0% object, and C is the speed of light, a 00:05:21.480 --> 00:05:24.270 align:start position:0% object, and C is the speed of light, a figure<00:05:21.880> we<00:05:22.000> know<00:05:22.240> to<00:05:22.400> be<00:05:22.680> roughly<00:05:23.080> 300<00:05:23.800> million 00:05:24.270 --> 00:05:24.280 align:start position:0% figure we know to be roughly 300 million 00:05:24.280 --> 00:05:26.150 align:start position:0% figure we know to be roughly 300 million m/s.<00:05:24.883> [music] 00:05:26.150 --> 00:05:26.160 align:start position:0% m/s. [music] 00:05:26.160 --> 00:05:28.310 align:start position:0% m/s. [music] So,<00:05:26.480> to<00:05:26.640> find<00:05:26.919> out<00:05:27.120> how<00:05:27.400> much<00:05:27.720> slower<00:05:28.040> time 00:05:28.310 --> 00:05:28.320 align:start position:0% So, to find out how much slower time 00:05:28.320 --> 00:05:30.270 align:start position:0% So, to find out how much slower time goes<00:05:28.560> on<00:05:28.760> Earth<00:05:29.200> compared<00:05:29.520> to<00:05:29.640> somewhere 00:05:30.270 --> 00:05:30.280 align:start position:0% goes on Earth compared to somewhere 00:05:30.280 --> 00:05:32.470 align:start position:0% goes on Earth compared to somewhere where<00:05:30.440> there<00:05:30.560> was<00:05:30.720> no<00:05:31.000> gravity,<00:05:32.000> all<00:05:32.160> we<00:05:32.280> have 00:05:32.470 --> 00:05:32.480 align:start position:0% where there was no gravity, all we have 00:05:32.480 --> 00:05:35.670 align:start position:0% where there was no gravity, all we have to<00:05:32.600> know<00:05:32.919> is<00:05:33.160> how<00:05:33.440> much<00:05:33.800> mass<00:05:34.240> the<00:05:34.440> Earth<00:05:34.680> has, 00:05:35.670 --> 00:05:35.680 align:start position:0% to know is how much mass the Earth has, 00:05:35.680 --> 00:05:38.230 align:start position:0% to know is how much mass the Earth has, how<00:05:35.960> far<00:05:36.360> we<00:05:36.520> are<00:05:36.720> from<00:05:36.919> its<00:05:37.080> center, 00:05:38.230 --> 00:05:38.240 align:start position:0% how far we are from its center, 00:05:38.240 --> 00:05:40.110 align:start position:0% how far we are from its center, and<00:05:38.360> then<00:05:38.480> we<00:05:38.600> can<00:05:38.720> decide<00:05:39.200> how<00:05:39.440> much<00:05:39.680> time<00:05:40.000> we 00:05:40.110 --> 00:05:40.120 align:start position:0% and then we can decide how much time we 00:05:40.120 --> 00:05:42.110 align:start position:0% and then we can decide how much time we want<00:05:40.360> to<00:05:40.440> compare. 00:05:42.110 --> 00:05:42.120 align:start position:0% want to compare. 00:05:42.120 --> 00:05:44.630 align:start position:0% want to compare. Just<00:05:42.400> to<00:05:42.520> ease<00:05:42.840> ourselves<00:05:43.440> in,<00:05:44.080> I<00:05:44.160> decided<00:05:44.560> to 00:05:44.630 --> 00:05:44.640 align:start position:0% Just to ease ourselves in, I decided to 00:05:44.640 --> 00:05:47.510 align:start position:0% Just to ease ourselves in, I decided to try<00:05:44.840> this<00:05:45.040> formula<00:05:45.560> out<00:05:45.800> with<00:05:46.000> 60<00:05:46.360> seconds. 00:05:47.510 --> 00:05:47.520 align:start position:0% try this formula out with 60 seconds. 00:05:47.520 --> 00:05:49.910 align:start position:0% try this formula out with 60 seconds. If<00:05:47.680> 60<00:05:48.080> seconds<00:05:48.520> passes<00:05:49.080> in<00:05:49.280> our<00:05:49.480> place 00:05:49.910 --> 00:05:49.920 align:start position:0% If 60 seconds passes in our place 00:05:49.920 --> 00:05:52.190 align:start position:0% If 60 seconds passes in our place unaffected<00:05:50.480> by<00:05:50.600> gravity,<00:05:51.560> how<00:05:51.720> much<00:05:51.920> time 00:05:52.190 --> 00:05:52.200 align:start position:0% unaffected by gravity, how much time 00:05:52.200 --> 00:05:53.750 align:start position:0% unaffected by gravity, how much time passes<00:05:52.600> on<00:05:52.800> Earth? 00:05:53.750 --> 00:05:53.760 align:start position:0% passes on Earth? 00:05:53.760 --> 00:05:56.110 align:start position:0% passes on Earth? I<00:05:53.840> plugged<00:05:54.240> in<00:05:54.360> the<00:05:54.440> information<00:05:55.280> and<00:05:55.520> got<00:05:55.840> our 00:05:56.110 --> 00:05:56.120 align:start position:0% I plugged in the information and got our 00:05:56.120 --> 00:05:57.670 align:start position:0% I plugged in the information and got our result. 00:05:57.670 --> 00:05:57.680 align:start position:0% result. 00:05:57.680 --> 00:06:00.950 align:start position:0% result. For<00:05:58.000> every<00:05:58.320> 60<00:05:58.840> seconds<00:05:59.440> that<00:05:59.600> passes,<00:06:00.520> people 00:06:00.950 --> 00:06:00.960 align:start position:0% For every 60 seconds that passes, people 00:06:00.960 --> 00:06:06.990 align:start position:0% For every 60 seconds that passes, people on<00:06:01.200> Earth<00:06:01.480> experience<00:06:02.280> only<00:06:02.600> 59.9999996 00:06:06.990 --> 00:06:07.000 align:start position:0% 00:06:07.000 --> 00:06:08.270 align:start position:0% seconds. 00:06:08.270 --> 00:06:08.280 align:start position:0% seconds. 00:06:08.280 --> 00:06:10.950 align:start position:0% seconds. In<00:06:08.400> other<00:06:08.600> words,<00:06:09.320> 6<00:06:09.800> billion<00:06:10.320> seconds<00:06:10.800> have 00:06:10.950 --> 00:06:10.960 align:start position:0% In other words, 6 billion seconds have 00:06:10.960 --> 00:06:12.950 align:start position:0% In other words, 6 billion seconds have to<00:06:11.040> go<00:06:11.240> by<00:06:11.600> before<00:06:11.920> we<00:06:12.040> notice<00:06:12.440> a<00:06:12.480> difference 00:06:12.950 --> 00:06:12.960 align:start position:0% to go by before we notice a difference 00:06:12.960 --> 00:06:14.830 align:start position:0% to go by before we notice a difference of<00:06:13.240> 4<00:06:13.520> seconds. 00:06:14.830 --> 00:06:14.840 align:start position:0% of 4 seconds. 00:06:14.840 --> 00:06:17.670 align:start position:0% of 4 seconds. This<00:06:15.080> happens<00:06:15.560> roughly<00:06:15.960> once<00:06:16.320> every<00:06:16.640> 190 00:06:17.670 --> 00:06:17.680 align:start position:0% This happens roughly once every 190 00:06:17.680 --> 00:06:18.909 align:start position:0% This happens roughly once every 190 years. 00:06:18.909 --> 00:06:18.919 align:start position:0% years. 00:06:18.919 --> 00:06:20.870 align:start position:0% years. So,<00:06:19.080> realistically,<00:06:20.080> you'll<00:06:20.360> only<00:06:20.600> gain 00:06:20.870 --> 00:06:20.880 align:start position:0% So, realistically, you'll only gain 00:06:20.880 --> 00:06:23.110 align:start position:0% So, realistically, you'll only gain about<00:06:21.280> 2<00:06:21.560> seconds<00:06:22.160> over<00:06:22.320> the<00:06:22.440> course<00:06:22.760> of<00:06:22.840> your 00:06:23.110 --> 00:06:23.120 align:start position:0% about 2 seconds over the course of your 00:06:23.120 --> 00:06:25.150 align:start position:0% about 2 seconds over the course of your entire<00:06:23.560> lifetime<00:06:24.280> because<00:06:24.600> of<00:06:24.680> the<00:06:24.880> Earth's 00:06:25.150 --> 00:06:25.160 align:start position:0% entire lifetime because of the Earth's 00:06:25.160 --> 00:06:27.110 align:start position:0% entire lifetime because of the Earth's gravity<00:06:25.880> compared<00:06:26.240> to<00:06:26.360> a<00:06:26.400> place<00:06:26.760> with<00:06:26.919> no 00:06:27.110 --> 00:06:27.120 align:start position:0% gravity compared to a place with no 00:06:27.120 --> 00:06:28.510 align:start position:0% gravity compared to a place with no gravity. 00:06:28.510 --> 00:06:28.520 align:start position:0% gravity. 00:06:28.520 --> 00:06:31.310 align:start position:0% gravity. This<00:06:28.800> is<00:06:29.040> a<00:06:29.120> little<00:06:29.560> underwhelming. 00:06:31.310 --> 00:06:31.320 align:start position:0% This is a little underwhelming. 00:06:31.320 --> 00:06:33.590 align:start position:0% This is a little underwhelming. However,<00:06:31.840> we<00:06:32.200> here<00:06:32.480> on<00:06:32.680> Earth<00:06:33.000> are<00:06:33.120> not<00:06:33.400> just 00:06:33.590 --> 00:06:33.600 align:start position:0% However, we here on Earth are not just 00:06:33.600 --> 00:06:36.110 align:start position:0% However, we here on Earth are not just affected<00:06:34.000> by<00:06:34.240> our<00:06:34.480> planet's<00:06:34.919> gravity.<00:06:35.840> We<00:06:36.000> are 00:06:36.110 --> 00:06:36.120 align:start position:0% affected by our planet's gravity. We are 00:06:36.120 --> 00:06:38.670 align:start position:0% affected by our planet's gravity. We are also<00:06:36.400> affected<00:06:36.880> by<00:06:37.000> the<00:06:37.080> gravity<00:06:37.560> of<00:06:37.680> the<00:06:37.800> Sun, 00:06:38.670 --> 00:06:38.680 align:start position:0% also affected by the gravity of the Sun, 00:06:38.680 --> 00:06:40.710 align:start position:0% also affected by the gravity of the Sun, which<00:06:38.880> in<00:06:39.000> terms<00:06:39.320> of<00:06:39.440> our<00:06:39.600> equation<00:06:40.080> is<00:06:40.280> much 00:06:40.710 --> 00:06:40.720 align:start position:0% which in terms of our equation is much 00:06:40.720 --> 00:06:42.950 align:start position:0% which in terms of our equation is much more<00:06:40.880> significant.<00:06:42.000> So,<00:06:42.320> let's<00:06:42.600> try<00:06:42.800> this 00:06:42.950 --> 00:06:42.960 align:start position:0% more significant. So, let's try this 00:06:42.960 --> 00:06:45.670 align:start position:0% more significant. So, let's try this again<00:06:43.320> by<00:06:43.560> inputting<00:06:44.080> the<00:06:44.200> mass<00:06:44.480> of<00:06:44.600> the<00:06:44.720> Sun 00:06:45.670 --> 00:06:45.680 align:start position:0% again by inputting the mass of the Sun 00:06:45.680 --> 00:06:47.630 align:start position:0% again by inputting the mass of the Sun and<00:06:45.840> our<00:06:46.040> distance<00:06:46.520> from<00:06:46.880> it<00:06:47.320> into<00:06:47.520> the 00:06:47.630 --> 00:06:47.640 align:start position:0% and our distance from it into the 00:06:47.640 --> 00:06:49.270 align:start position:0% and our distance from it into the equation. 00:06:49.270 --> 00:06:49.280 align:start position:0% equation. 00:06:49.280 --> 00:06:51.830 align:start position:0% equation. This<00:06:49.520> gives<00:06:49.800> us<00:06:49.960> the<00:06:50.080> new<00:06:50.320> figure.<00:06:51.400> How<00:06:51.560> much 00:06:51.830 --> 00:06:51.840 align:start position:0% This gives us the new figure. How much 00:06:51.840 --> 00:06:53.909 align:start position:0% This gives us the new figure. How much time<00:06:52.160> goes<00:06:52.440> by<00:06:52.680> for<00:06:52.880> us<00:06:53.040> on<00:06:53.280> Earth<00:06:53.560> for<00:06:53.680> every 00:06:53.909 --> 00:06:53.919 align:start position:0% time goes by for us on Earth for every 00:06:53.919 --> 00:06:57.270 align:start position:0% time goes by for us on Earth for every 60<00:06:54.400> seconds<00:06:54.800> of<00:06:55.000> actual<00:06:55.360> time<00:06:55.640> that<00:06:55.760> goes<00:06:56.000> by? 00:06:57.270 --> 00:06:57.280 align:start position:0% 60 seconds of actual time that goes by? 00:06:57.280 --> 00:07:01.110 align:start position:0% 60 seconds of actual time that goes by? 59.9999994 00:07:01.110 --> 00:07:01.120 align:start position:0% 00:07:01.120 --> 00:07:03.270 align:start position:0% seconds. 00:07:03.270 --> 00:07:03.280 align:start position:0% seconds. 00:07:03.280 --> 00:07:05.670 align:start position:0% seconds. While<00:07:03.520> this<00:07:03.760> is<00:07:03.880> a<00:07:03.960> more<00:07:04.240> significant<00:07:05.000> number, 00:07:05.670 --> 00:07:05.680 align:start position:0% While this is a more significant number, 00:07:05.680 --> 00:07:07.870 align:start position:0% While this is a more significant number, it<00:07:05.960> does<00:07:06.280> mean<00:07:06.600> that<00:07:06.880> you<00:07:07.000> are<00:07:07.200> only<00:07:07.440> seeing<00:07:07.800> a 00:07:07.870 --> 00:07:07.880 align:start position:0% it does mean that you are only seeing a 00:07:07.880 --> 00:07:10.150 align:start position:0% it does mean that you are only seeing a difference<00:07:08.400> of<00:07:08.520> a<00:07:08.600> second<00:07:09.200> once<00:07:09.520> every<00:07:09.800> 3 00:07:10.150 --> 00:07:10.160 align:start position:0% difference of a second once every 3 00:07:10.160 --> 00:07:11.590 align:start position:0% difference of a second once every 3 years<00:07:10.520> or<00:07:10.640> so. 00:07:11.590 --> 00:07:11.600 align:start position:0% years or so. 00:07:11.600 --> 00:07:14.390 align:start position:0% years or so. Or<00:07:11.720> in<00:07:11.840> other<00:07:12.040> words,<00:07:12.720> about<00:07:13.080> 24<00:07:13.680> seconds<00:07:14.200> over 00:07:14.390 --> 00:07:14.400 align:start position:0% Or in other words, about 24 seconds over 00:07:14.400 --> 00:07:17.750 align:start position:0% Or in other words, about 24 seconds over the<00:07:14.520> course<00:07:14.880> of<00:07:15.000> an<00:07:15.160> average<00:07:15.560> human<00:07:15.880> lifetime. 00:07:17.750 --> 00:07:17.760 align:start position:0% the course of an average human lifetime. 00:07:17.760 --> 00:07:20.590 align:start position:0% the course of an average human lifetime. But,<00:07:18.240> Mercury<00:07:18.840> is<00:07:19.040> much<00:07:19.400> closer<00:07:19.720> to<00:07:19.840> the<00:07:19.960> Sun. 00:07:20.590 --> 00:07:20.600 align:start position:0% But, Mercury is much closer to the Sun. 00:07:20.600 --> 00:07:22.670 align:start position:0% But, Mercury is much closer to the Sun. Surely,<00:07:21.000> time<00:07:21.360> is<00:07:21.480> significantly<00:07:22.360> altered 00:07:22.670 --> 00:07:22.680 align:start position:0% Surely, time is significantly altered 00:07:22.680 --> 00:07:24.710 align:start position:0% Surely, time is significantly altered here<00:07:23.000> compared<00:07:23.360> to<00:07:23.520> Earth<00:07:23.960> with<00:07:24.120> a<00:07:24.200> massive 00:07:24.710 --> 00:07:24.720 align:start position:0% here compared to Earth with a massive 00:07:24.720 --> 00:07:27.510 align:start position:0% here compared to Earth with a massive object<00:07:25.040> like<00:07:25.200> the<00:07:25.280> Sun<00:07:25.600> so<00:07:25.880> close<00:07:26.200> by. 00:07:27.510 --> 00:07:27.520 align:start position:0% object like the Sun so close by. 00:07:27.520 --> 00:07:29.350 align:start position:0% object like the Sun so close by. How<00:07:27.600> much<00:07:27.800> more<00:07:28.040> does<00:07:28.240> time<00:07:28.520> slow<00:07:28.720> down<00:07:29.000> for<00:07:29.160> us 00:07:29.350 --> 00:07:29.360 align:start position:0% How much more does time slow down for us 00:07:29.360 --> 00:07:31.110 align:start position:0% How much more does time slow down for us on<00:07:29.560> Mercury? 00:07:31.110 --> 00:07:31.120 align:start position:0% on Mercury? 00:07:31.120 --> 00:07:32.750 align:start position:0% on Mercury? The<00:07:31.160> equation<00:07:31.600> is<00:07:31.720> essentially<00:07:32.240> the<00:07:32.360> same<00:07:32.640> as 00:07:32.750 --> 00:07:32.760 align:start position:0% The equation is essentially the same as 00:07:32.760 --> 00:07:34.990 align:start position:0% The equation is essentially the same as before.<00:07:33.520> The<00:07:33.640> only<00:07:33.840> new<00:07:34.080> number<00:07:34.400> we<00:07:34.520> need<00:07:34.840> is 00:07:34.990 --> 00:07:35.000 align:start position:0% before. The only new number we need is 00:07:35.000 --> 00:07:36.510 align:start position:0% before. The only new number we need is the<00:07:35.120> distance<00:07:35.560> between<00:07:35.880> the<00:07:36.000> Sun<00:07:36.360> and 00:07:36.510 --> 00:07:36.520 align:start position:0% the distance between the Sun and 00:07:36.520 --> 00:07:38.030 align:start position:0% the distance between the Sun and Mercury. 00:07:38.030 --> 00:07:38.040 align:start position:0% Mercury. 00:07:38.040 --> 00:07:40.470 align:start position:0% Mercury. The<00:07:38.200> answer<00:07:38.520> to<00:07:38.720> our<00:07:38.960> final<00:07:39.400> question<00:07:39.960> of<00:07:40.160> how 00:07:40.470 --> 00:07:40.480 align:start position:0% The answer to our final question of how 00:07:40.480 --> 00:07:43.150 align:start position:0% The answer to our final question of how much<00:07:40.760> time<00:07:41.120> passes<00:07:41.600> on<00:07:41.800> Mercury<00:07:42.400> every<00:07:42.720> 60 00:07:43.150 --> 00:07:43.160 align:start position:0% much time passes on Mercury every 60 00:07:43.160 --> 00:07:44.790 align:start position:0% much time passes on Mercury every 60 seconds<00:07:43.720> is 00:07:44.790 --> 00:07:44.800 align:start position:0% seconds is 00:07:44.800 --> 00:07:48.190 align:start position:0% seconds is 59.999999 00:07:48.190 --> 00:07:48.200 align:start position:0% 00:07:48.200 --> 00:07:49.830 align:start position:0% seconds. 00:07:49.830 --> 00:07:49.840 align:start position:0% seconds. 00:07:49.840 --> 00:07:52.830 align:start position:0% seconds. 60<00:07:50.400> million<00:07:50.960> seconds<00:07:51.520> need<00:07:51.720> to<00:07:51.840> go<00:07:52.040> by<00:07:52.520> before 00:07:52.830 --> 00:07:52.840 align:start position:0% 60 million seconds need to go by before 00:07:52.840 --> 00:07:55.550 align:start position:0% 60 million seconds need to go by before there's<00:07:53.040> a<00:07:53.120> single<00:07:53.720> seconds<00:07:54.240> difference. 00:07:55.550 --> 00:07:55.560 align:start position:0% there's a single seconds difference. 00:07:55.560 --> 00:07:57.830 align:start position:0% there's a single seconds difference. This<00:07:55.720> happens<00:07:56.160> roughly<00:07:56.520> once<00:07:56.840> every<00:07:57.080> 1.9 00:07:57.830 --> 00:07:57.840 align:start position:0% This happens roughly once every 1.9 00:07:57.840 --> 00:08:00.910 align:start position:0% This happens roughly once every 1.9 years,<00:07:58.680> which<00:07:59.040> scaled<00:07:59.480> up<00:07:59.680> across<00:08:00.000> a<00:08:00.080> lifetime 00:08:00.910 --> 00:08:00.920 align:start position:0% years, which scaled up across a lifetime 00:08:00.920 --> 00:08:04.270 align:start position:0% years, which scaled up across a lifetime equates<00:08:01.440> to<00:08:01.600> about<00:08:01.960> 38<00:08:02.640> seconds<00:08:03.080> difference. 00:08:04.270 --> 00:08:04.280 align:start position:0% equates to about 38 seconds difference. 00:08:04.280 --> 00:08:07.150 align:start position:0% equates to about 38 seconds difference. Only<00:08:04.560> 14<00:08:05.040> more<00:08:05.240> seconds<00:08:05.680> than<00:08:05.880> Earth. 00:08:07.150 --> 00:08:07.160 align:start position:0% Only 14 more seconds than Earth. 00:08:07.160 --> 00:08:09.550 align:start position:0% Only 14 more seconds than Earth. But<00:08:07.360> from<00:08:07.720> your<00:08:08.000> point<00:08:08.280> of<00:08:08.360> view,<00:08:08.960> you're<00:08:09.240> not 00:08:09.550 --> 00:08:09.560 align:start position:0% But from your point of view, you're not 00:08:09.560 --> 00:08:11.590 align:start position:0% But from your point of view, you're not really<00:08:09.960> gaining<00:08:10.320> those<00:08:10.520> seconds<00:08:11.120> because 00:08:11.590 --> 00:08:11.600 align:start position:0% really gaining those seconds because 00:08:11.600 --> 00:08:13.390 align:start position:0% really gaining those seconds because from<00:08:11.840> your<00:08:12.000> perspective<00:08:12.800> time<00:08:13.120> would<00:08:13.280> be 00:08:13.390 --> 00:08:13.400 align:start position:0% from your perspective time would be 00:08:13.400 --> 00:08:15.150 align:start position:0% from your perspective time would be moving<00:08:13.760> normally. 00:08:15.150 --> 00:08:15.160 align:start position:0% moving normally. 00:08:15.160 --> 00:08:16.909 align:start position:0% moving normally. It<00:08:15.240> would<00:08:15.360> be<00:08:15.520> the<00:08:15.760> Earth<00:08:16.120> that<00:08:16.280> is<00:08:16.400> moving 00:08:16.909 --> 00:08:16.919 align:start position:0% It would be the Earth that is moving 00:08:16.919 --> 00:08:18.790 align:start position:0% It would be the Earth that is moving ever<00:08:17.200> so<00:08:17.400> slightly<00:08:17.760> faster<00:08:18.200> from<00:08:18.360> your<00:08:18.560> point 00:08:18.790 --> 00:08:18.800 align:start position:0% ever so slightly faster from your point 00:08:18.800 --> 00:08:20.430 align:start position:0% ever so slightly faster from your point of<00:08:18.880> view. 00:08:20.430 --> 00:08:20.440 align:start position:0% of view. 00:08:20.440 --> 00:08:22.430 align:start position:0% of view. So,<00:08:20.720> if<00:08:20.880> you<00:08:21.000> pointed<00:08:21.360> a<00:08:21.400> telescope<00:08:22.000> towards 00:08:22.430 --> 00:08:22.440 align:start position:0% So, if you pointed a telescope towards 00:08:22.440 --> 00:08:25.070 align:start position:0% So, if you pointed a telescope towards Earth,<00:08:23.040> you'd<00:08:23.320> see<00:08:23.560> 14<00:08:24.240> more<00:08:24.480> seconds<00:08:24.880> of 00:08:25.070 --> 00:08:25.080 align:start position:0% Earth, you'd see 14 more seconds of 00:08:25.080 --> 00:08:26.990 align:start position:0% Earth, you'd see 14 more seconds of Earth's<00:08:25.280> history<00:08:26.200> than<00:08:26.360> you<00:08:26.480> would<00:08:26.720> if<00:08:26.880> you 00:08:26.990 --> 00:08:27.000 align:start position:0% Earth's history than you would if you 00:08:27.000 --> 00:08:29.550 align:start position:0% Earth's history than you would if you were<00:08:27.080> living<00:08:27.400> there. 00:08:29.550 --> 00:08:29.560 align:start position:0% were living there. 00:08:29.560 --> 00:08:32.750 align:start position:0% were living there. As<00:08:29.840> Mercury<00:08:30.440> is<00:08:30.760> fairly<00:08:31.240> inhospitable,<00:08:32.520> this 00:08:32.750 --> 00:08:32.760 align:start position:0% As Mercury is fairly inhospitable, this 00:08:32.760 --> 00:08:35.630 align:start position:0% As Mercury is fairly inhospitable, this probably<00:08:33.320> isn't<00:08:33.599> worth<00:08:33.880> it. 00:08:35.630 --> 00:08:35.640 align:start position:0% probably isn't worth it. 00:08:35.640 --> 00:08:37.990 align:start position:0% probably isn't worth it. So,<00:08:36.000> does<00:08:36.280> Mercury's<00:08:36.760> proximity<00:08:37.360> to<00:08:37.479> the<00:08:37.599> Sun 00:08:37.990 --> 00:08:38.000 align:start position:0% So, does Mercury's proximity to the Sun 00:08:38.000 --> 00:08:39.709 align:start position:0% So, does Mercury's proximity to the Sun allow<00:08:38.280> time<00:08:38.640> to<00:08:38.760> move<00:08:38.960> slower<00:08:39.400> for<00:08:39.520> you 00:08:39.709 --> 00:08:39.719 align:start position:0% allow time to move slower for you 00:08:39.719 --> 00:08:42.870 align:start position:0% allow time to move slower for you compared<00:08:40.080> to<00:08:40.240> Earth?<00:08:41.120> Yes,<00:08:42.039> but<00:08:42.360> only<00:08:42.640> by<00:08:42.800> a 00:08:42.870 --> 00:08:42.880 align:start position:0% compared to Earth? Yes, but only by a 00:08:42.880 --> 00:08:45.270 align:start position:0% compared to Earth? Yes, but only by a difference<00:08:43.280> of<00:08:43.400> about<00:08:43.760> 14<00:08:44.360> seconds<00:08:44.920> over<00:08:45.120> your 00:08:45.270 --> 00:08:45.280 align:start position:0% difference of about 14 seconds over your 00:08:45.280 --> 00:08:47.190 align:start position:0% difference of about 14 seconds over your entire<00:08:45.720> lifetime. 00:08:47.190 --> 00:08:47.200 align:start position:0% entire lifetime. 00:08:47.200 --> 00:08:49.630 align:start position:0% entire lifetime. In<00:08:47.320> reality,<00:08:47.920> time<00:08:48.200> dilation<00:08:48.760> due<00:08:49.000> to<00:08:49.120> gravity 00:08:49.630 --> 00:08:49.640 align:start position:0% In reality, time dilation due to gravity 00:08:49.640 --> 00:08:52.390 align:start position:0% In reality, time dilation due to gravity is<00:08:49.920> not<00:08:50.360> actually<00:08:50.880> that<00:08:51.080> significant,<00:08:52.200> at 00:08:52.390 --> 00:08:52.400 align:start position:0% is not actually that significant, at 00:08:52.400 --> 00:08:54.990 align:start position:0% is not actually that significant, at least<00:08:52.760> not<00:08:53.080> in<00:08:53.200> our<00:08:53.440> own<00:08:53.640> solar<00:08:53.920> system. 00:08:54.990 --> 00:08:55.000 align:start position:0% least not in our own solar system. 00:08:55.000 --> 00:08:56.670 align:start position:0% least not in our own solar system. The<00:08:55.040> mass<00:08:55.320> of<00:08:55.400> the<00:08:55.520> Sun<00:08:55.760> is<00:08:55.880> not<00:08:56.200> enough<00:08:56.560> to 00:08:56.670 --> 00:08:56.680 align:start position:0% The mass of the Sun is not enough to 00:08:56.680 --> 00:08:58.750 align:start position:0% The mass of the Sun is not enough to really<00:08:56.880> stretch<00:08:57.400> time<00:08:57.720> that<00:08:57.920> much<00:08:58.160> for<00:08:58.400> us, 00:08:58.750 --> 00:08:58.760 align:start position:0% really stretch time that much for us, 00:08:58.760 --> 00:09:00.230 align:start position:0% really stretch time that much for us, even<00:08:58.960> if<00:08:59.080> we<00:08:59.240> were<00:08:59.480> as<00:08:59.640> close<00:08:59.880> to<00:09:00.000> it<00:09:00.120> as 00:09:00.230 --> 00:09:00.240 align:start position:0% even if we were as close to it as 00:09:00.240 --> 00:09:01.390 align:start position:0% even if we were as close to it as Mercury. 00:09:01.390 --> 00:09:01.400 align:start position:0% Mercury. 00:09:01.400 --> 00:09:02.990 align:start position:0% Mercury. The<00:09:01.480> Sun<00:09:01.720> would<00:09:01.839> need<00:09:02.040> to<00:09:02.120> be<00:09:02.280> millions<00:09:02.880> of 00:09:02.990 --> 00:09:03.000 align:start position:0% The Sun would need to be millions of 00:09:03.000 --> 00:09:04.990 align:start position:0% The Sun would need to be millions of times<00:09:03.320> more<00:09:03.520> massive<00:09:03.960> before<00:09:04.320> we<00:09:04.480> would<00:09:04.640> begin 00:09:04.990 --> 00:09:05.000 align:start position:0% times more massive before we would begin 00:09:05.000 --> 00:09:06.870 align:start position:0% times more massive before we would begin to<00:09:05.120> experience<00:09:05.680> time<00:09:05.960> dilation<00:09:06.560> to<00:09:06.720> any 00:09:06.870 --> 00:09:06.880 align:start position:0% to experience time dilation to any 00:09:06.880 --> 00:09:08.950 align:start position:0% to experience time dilation to any significant<00:09:07.560> degree. 00:09:08.950 --> 00:09:08.960 align:start position:0% significant degree. 00:09:08.960 --> 00:09:10.630 align:start position:0% significant degree. However,<00:09:09.440> it's<00:09:09.600> still<00:09:09.800> a<00:09:09.880> fascinating 00:09:10.630 --> 00:09:10.640 align:start position:0% However, it's still a fascinating 00:09:10.640 --> 00:09:12.590 align:start position:0% However, it's still a fascinating insight<00:09:11.120> into<00:09:11.320> the<00:09:11.440> way<00:09:11.680> that<00:09:11.880> time<00:09:12.120> flows<00:09:12.480> in 00:09:12.590 --> 00:09:12.600 align:start position:0% insight into the way that time flows in 00:09:12.600 --> 00:09:14.790 align:start position:0% insight into the way that time flows in our<00:09:12.760> universe<00:09:13.720> and<00:09:13.839> reveals<00:09:14.200> that<00:09:14.360> time<00:09:14.640> is 00:09:14.790 --> 00:09:14.800 align:start position:0% our universe and reveals that time is 00:09:14.800 --> 00:09:17.630 align:start position:0% our universe and reveals that time is not<00:09:15.200> as<00:09:15.320> constant<00:09:15.800> as<00:09:15.920> we<00:09:16.040> might<00:09:16.280> think. 00:09:17.630 --> 00:09:17.640 align:start position:0% not as constant as we might think. 00:09:17.640 --> 00:09:19.710 align:start position:0% not as constant as we might think. And<00:09:17.760> of<00:09:17.880> course,<00:09:18.360> it<00:09:18.560> begs<00:09:19.000> one<00:09:19.400> final 00:09:19.710 --> 00:09:19.720 align:start position:0% And of course, it begs one final 00:09:19.720 --> 00:09:20.829 align:start position:0% And of course, it begs one final question. 00:09:20.829 --> 00:09:20.839 align:start position:0% question. 00:09:20.839 --> 00:09:22.390 align:start position:0% question. Are<00:09:21.000> there<00:09:21.240> any<00:09:21.440> objects<00:09:21.839> in<00:09:21.920> the<00:09:22.000> universe 00:09:22.390 --> 00:09:22.400 align:start position:0% Are there any objects in the universe 00:09:22.400 --> 00:09:24.230 align:start position:0% Are there any objects in the universe that<00:09:22.800> are<00:09:23.080> massive<00:09:23.440> enough<00:09:23.839> that<00:09:24.040> we'd 00:09:24.230 --> 00:09:24.240 align:start position:0% that are massive enough that we'd 00:09:24.240 --> 00:09:26.150 align:start position:0% that are massive enough that we'd experience<00:09:24.720> significant<00:09:25.480> time<00:09:25.720> dilation 00:09:26.150 --> 00:09:26.160 align:start position:0% experience significant time dilation 00:09:26.160 --> 00:09:28.230 align:start position:0% experience significant time dilation around<00:09:26.520> them? 00:09:28.230 --> 00:09:28.240 align:start position:0% around them? 00:09:28.240 --> 00:09:29.510 align:start position:0% around them? There<00:09:28.560> are. 00:09:29.510 --> 00:09:29.520 align:start position:0% There are. 00:09:29.520 --> 00:09:30.990 align:start position:0% There are. And<00:09:29.600> this<00:09:29.760> is<00:09:29.880> where<00:09:30.040> things<00:09:30.320> start<00:09:30.600> to<00:09:30.680> get 00:09:30.990 --> 00:09:31.000 align:start position:0% And this is where things start to get 00:09:31.000 --> 00:09:34.910 align:start position:0% And this is where things start to get very<00:09:31.400> noticeable<00:09:32.120> to<00:09:32.240> an<00:09:32.400> outside<00:09:32.839> observer. 00:09:34.910 --> 00:09:34.920 align:start position:0% very noticeable to an outside observer. 00:09:34.920 --> 00:09:36.910 align:start position:0% very noticeable to an outside observer. At<00:09:35.040> the<00:09:35.120> center<00:09:35.480> of<00:09:35.600> galaxies<00:09:36.400> exist<00:09:36.420> [music] 00:09:36.910 --> 00:09:36.920 align:start position:0% At the center of galaxies exist [music] 00:09:36.920 --> 00:09:39.070 align:start position:0% At the center of galaxies exist [music] objects<00:09:37.440> known<00:09:37.880> as<00:09:38.120> super<00:09:38.440> massive<00:09:38.800> black 00:09:39.070 --> 00:09:39.080 align:start position:0% objects known as super massive black 00:09:39.080 --> 00:09:40.190 align:start position:0% objects known as super massive black holes. 00:09:40.190 --> 00:09:40.200 align:start position:0% holes. 00:09:40.200 --> 00:09:41.590 align:start position:0% holes. These<00:09:40.360> objects<00:09:40.720> have<00:09:40.880> masses<00:09:41.280> that<00:09:41.480> are 00:09:41.590 --> 00:09:41.600 align:start position:0% These objects have masses that are 00:09:41.600 --> 00:09:43.910 align:start position:0% These objects have masses that are millions<00:09:42.240> to<00:09:42.440> billions<00:09:43.040> of<00:09:43.160> times<00:09:43.600> the<00:09:43.680> mass 00:09:43.910 --> 00:09:43.920 align:start position:0% millions to billions of times the mass 00:09:43.920 --> 00:09:45.390 align:start position:0% millions to billions of times the mass of<00:09:44.040> our<00:09:44.240> sun. 00:09:45.390 --> 00:09:45.400 align:start position:0% of our sun. 00:09:45.400 --> 00:09:47.030 align:start position:0% of our sun. In<00:09:45.520> other<00:09:45.720> words,<00:09:46.200> if<00:09:46.360> you<00:09:46.440> were<00:09:46.520> to<00:09:46.680> fall 00:09:47.030 --> 00:09:47.040 align:start position:0% In other words, if you were to fall 00:09:47.040 --> 00:09:49.470 align:start position:0% In other words, if you were to fall towards<00:09:47.520> them,<00:09:48.080> time<00:09:48.440> could<00:09:48.760> slow<00:09:49.000> down<00:09:49.360> for 00:09:49.470 --> 00:09:49.480 align:start position:0% towards them, time could slow down for 00:09:49.480 --> 00:09:52.950 align:start position:0% towards them, time could slow down for you<00:09:49.680> so<00:09:50.000> much<00:09:50.480> that<00:09:50.680> it<00:09:50.800> would<00:09:50.920> approach<00:09:51.400> zero. 00:09:52.950 --> 00:09:52.960 align:start position:0% you so much that it would approach zero. 00:09:52.960 --> 00:09:54.550 align:start position:0% you so much that it would approach zero. If<00:09:53.120> you<00:09:53.240> were<00:09:53.320> to<00:09:53.440> get<00:09:53.640> close<00:09:54.000> enough<00:09:54.280> to<00:09:54.400> one 00:09:54.550 --> 00:09:54.560 align:start position:0% If you were to get close enough to one 00:09:54.560 --> 00:09:57.190 align:start position:0% If you were to get close enough to one of<00:09:54.640> these<00:09:54.880> giants<00:09:55.480> and<00:09:55.760> later<00:09:56.080> escape<00:09:56.480> it,<00:09:57.120> you 00:09:57.190 --> 00:09:57.200 align:start position:0% of these giants and later escape it, you 00:09:57.200 --> 00:09:59.390 align:start position:0% of these giants and later escape it, you could<00:09:57.400> spend<00:09:57.800> half<00:09:58.120> an<00:09:58.280> hour<00:09:58.520> around<00:09:58.880> there 00:09:59.390 --> 00:09:59.400 align:start position:0% could spend half an hour around there 00:09:59.400 --> 00:10:01.350 align:start position:0% could spend half an hour around there and<00:09:59.560> emerge<00:10:00.080> to<00:10:00.200> find<00:10:00.640> that<00:10:00.660> [music]<00:10:00.880> hundreds 00:10:01.350 --> 00:10:01.360 align:start position:0% and emerge to find that [music] hundreds 00:10:01.360 --> 00:10:03.150 align:start position:0% and emerge to find that [music] hundreds of<00:10:01.480> years<00:10:01.840> had<00:10:02.000> passed<00:10:02.400> to<00:10:02.480> the<00:10:02.560> people<00:10:02.920> back 00:10:03.150 --> 00:10:03.160 align:start position:0% of years had passed to the people back 00:10:03.160 --> 00:10:05.350 align:start position:0% of years had passed to the people back on<00:10:03.320> Earth. 00:10:05.350 --> 00:10:05.360 align:start position:0% on Earth. 00:10:05.360 --> 00:10:07.150 align:start position:0% on Earth. People<00:10:05.680> on<00:10:05.920> Earth<00:10:06.280> with<00:10:06.400> a<00:10:06.480> powerful<00:10:06.920> enough 00:10:07.150 --> 00:10:07.160 align:start position:0% People on Earth with a powerful enough 00:10:07.160 --> 00:10:09.910 align:start position:0% People on Earth with a powerful enough telescope<00:10:08.080> would<00:10:08.280> see<00:10:08.480> you<00:10:08.680> barely<00:10:09.080> move. 00:10:09.910 --> 00:10:09.920 align:start position:0% telescope would see you barely move. 00:10:09.920 --> 00:10:11.030 align:start position:0% telescope would see you barely move. Even<00:10:10.200> your<00:10:10.400> breaths<00:10:10.467> [music] 00:10:11.030 --> 00:10:11.040 align:start position:0% Even your breaths [music] 00:10:11.040 --> 00:10:13.750 align:start position:0% Even your breaths [music] would<00:10:11.200> take<00:10:11.520> days<00:10:11.960> to<00:10:12.080> complete. 00:10:13.750 --> 00:10:13.760 align:start position:0% would take days to complete. 00:10:13.760 --> 00:10:16.110 align:start position:0% would take days to complete. In<00:10:13.920> fact,<00:10:14.560> there<00:10:14.720> would<00:10:14.960> be<00:10:15.080> a<00:10:15.120> point<00:10:15.600> right<00:10:16.040> at 00:10:16.110 --> 00:10:16.120 align:start position:0% In fact, there would be a point right at 00:10:16.120 --> 00:10:18.190 align:start position:0% In fact, there would be a point right at the<00:10:16.320> edge<00:10:16.600> of<00:10:16.720> such<00:10:16.960> a<00:10:17.040> body<00:10:17.680> that<00:10:17.920> as<00:10:18.080> you 00:10:18.190 --> 00:10:18.200 align:start position:0% the edge of such a body that as you 00:10:18.200 --> 00:10:21.510 align:start position:0% the edge of such a body that as you approached<00:10:18.720> it,<00:10:19.080> your<00:10:19.240> time<00:10:19.800> would<00:10:20.120> hit<00:10:20.360> zero. 00:10:21.510 --> 00:10:21.520 align:start position:0% approached it, your time would hit zero. 00:10:21.520 --> 00:10:22.710 align:start position:0% approached it, your time would hit zero. What<00:10:21.640> would<00:10:21.760> happen<00:10:22.040> if<00:10:22.160> you<00:10:22.240> passed<00:10:22.560> that 00:10:22.710 --> 00:10:22.720 align:start position:0% What would happen if you passed that 00:10:22.720 --> 00:10:25.990 align:start position:0% What would happen if you passed that point?<00:10:23.720> Our<00:10:23.920> equations<00:10:24.560> break<00:10:24.880> down<00:10:25.600> and<00:10:25.800> so 00:10:25.990 --> 00:10:26.000 align:start position:0% point? Our equations break down and so 00:10:26.000 --> 00:10:27.870 align:start position:0% point? Our equations break down and so cannot<00:10:26.400> explain<00:10:26.920> what<00:10:27.080> lies<00:10:27.400> beyond<00:10:27.720> that 00:10:27.870 --> 00:10:27.880 align:start position:0% cannot explain what lies beyond that 00:10:27.880 --> 00:10:30.350 align:start position:0% cannot explain what lies beyond that horizon.<00:10:28.880> Science<00:10:29.360> does<00:10:29.520> not<00:10:29.800> yet<00:10:30.080> have<00:10:30.240> the 00:10:30.350 --> 00:10:30.360 align:start position:0% horizon. Science does not yet have the 00:10:30.360 --> 00:10:32.230 align:start position:0% horizon. Science does not yet have the answer,<00:10:31.200> although<00:10:31.560> there<00:10:31.760> are<00:10:31.840> certainly 00:10:32.230 --> 00:10:32.240 align:start position:0% answer, although there are certainly 00:10:32.240 --> 00:10:33.870 align:start position:0% answer, although there are certainly many<00:10:32.560> theories. 00:10:33.870 --> 00:10:33.880 align:start position:0% many theories. 00:10:33.880 --> 00:10:35.510 align:start position:0% many theories. But<00:10:34.000> that<00:10:34.120> might<00:10:34.320> be<00:10:34.440> better<00:10:34.720> explored<00:10:35.400> in 00:10:35.510 --> 00:10:35.520 align:start position:0% But that might be better explored in 00:10:35.520 --> 00:10:38.230 align:start position:0% But that might be better explored in another<00:10:35.840> video. 00:10:38.230 --> 00:10:38.240 align:start position:0% another video. 00:10:38.240 --> 00:10:41.829 align:start position:0% another video. Movement<00:10:38.920> through<00:10:39.240> space<00:10:39.960> is<00:10:40.360> inevitable. 00:10:41.829 --> 00:10:41.839 align:start position:0% Movement through space is inevitable. 00:10:41.839 --> 00:10:43.990 align:start position:0% Movement through space is inevitable. You<00:10:41.920> might<00:10:42.120> not<00:10:42.320> feel<00:10:42.600> it,<00:10:43.080> but<00:10:43.280> right<00:10:43.560> now 00:10:43.990 --> 00:10:44.000 align:start position:0% You might not feel it, but right now 00:10:44.000 --> 00:10:45.670 align:start position:0% You might not feel it, but right now you're<00:10:44.280> sitting<00:10:44.680> on<00:10:44.800> a<00:10:44.880> planet<00:10:45.360> that<00:10:45.560> is 00:10:45.670 --> 00:10:45.680 align:start position:0% you're sitting on a planet that is 00:10:45.680 --> 00:10:48.070 align:start position:0% you're sitting on a planet that is spinning<00:10:46.200> on<00:10:46.320> its<00:10:46.480> axis,<00:10:47.320> moving<00:10:47.680> you<00:10:47.839> at<00:10:47.960> up 00:10:48.070 --> 00:10:48.080 align:start position:0% spinning on its axis, moving you at up 00:10:48.080 --> 00:10:50.230 align:start position:0% spinning on its axis, moving you at up to<00:10:48.280> 1,600 00:10:50.230 --> 00:10:50.240 align:start position:0% to 1,600 00:10:50.240 --> 00:10:53.430 align:start position:0% to 1,600 km/h<00:10:51.400> depending<00:10:51.800> on<00:10:51.920> your<00:10:52.040> latitude. 00:10:53.430 --> 00:10:53.440 align:start position:0% km/h depending on your latitude. 00:10:53.440 --> 00:10:55.870 align:start position:0% km/h depending on your latitude. The<00:10:53.600> Earth<00:10:53.960> circles<00:10:54.560> the<00:10:54.680> sun. 00:10:55.870 --> 00:10:55.880 align:start position:0% The Earth circles the sun. 00:10:55.880 --> 00:10:58.670 align:start position:0% The Earth circles the sun. The<00:10:55.960> sun<00:10:56.520> moves<00:10:56.800> through<00:10:57.120> the<00:10:57.240> Milky<00:10:57.600> Way. 00:10:58.670 --> 00:10:58.680 align:start position:0% The sun moves through the Milky Way. 00:10:58.680 --> 00:11:01.470 align:start position:0% The sun moves through the Milky Way. The<00:10:58.800> Milky<00:10:59.240> Way<00:10:59.640> moves<00:11:00.360> through<00:11:00.920> the<00:11:01.080> local 00:11:01.470 --> 00:11:01.480 align:start position:0% The Milky Way moves through the local 00:11:01.480 --> 00:11:03.790 align:start position:0% The Milky Way moves through the local group<00:11:01.800> of<00:11:01.920> galaxies. 00:11:03.790 --> 00:11:03.800 align:start position:0% group of galaxies. 00:11:03.800 --> 00:11:06.310 align:start position:0% group of galaxies. And<00:11:03.920> the<00:11:04.040> local<00:11:04.440> group<00:11:05.040> moves<00:11:05.560> through<00:11:06.080> our 00:11:06.310 --> 00:11:06.320 align:start position:0% And the local group moves through our 00:11:06.320 --> 00:11:08.510 align:start position:0% And the local group moves through our local<00:11:06.800> supercluster. 00:11:08.510 --> 00:11:08.520 align:start position:0% local supercluster. 00:11:08.520 --> 00:11:11.670 align:start position:0% local supercluster. And<00:11:08.880> even<00:11:09.400> that<00:11:09.839> supercluster<00:11:10.640> of<00:11:10.800> galaxies 00:11:11.670 --> 00:11:11.680 align:start position:0% And even that supercluster of galaxies 00:11:11.680 --> 00:11:14.350 align:start position:0% And even that supercluster of galaxies is<00:11:12.080> in<00:11:12.360> motion,<00:11:13.360> heading<00:11:13.760> towards<00:11:14.240> the 00:11:14.350 --> 00:11:14.360 align:start position:0% is in motion, heading towards the 00:11:14.360 --> 00:11:16.590 align:start position:0% is in motion, heading towards the Shapley<00:11:14.800> Supercluster,<00:11:16.000> where<00:11:16.120> scientists 00:11:16.590 --> 00:11:16.600 align:start position:0% Shapley Supercluster, where scientists 00:11:16.600 --> 00:11:19.030 align:start position:0% Shapley Supercluster, where scientists believe<00:11:17.160> that<00:11:17.320> there<00:11:17.600> is<00:11:17.880> a<00:11:18.000> particularly 00:11:19.030 --> 00:11:19.040 align:start position:0% believe that there is a particularly 00:11:19.040 --> 00:11:21.870 align:start position:0% believe that there is a particularly large<00:11:19.480> concentration<00:11:20.200> of<00:11:20.320> galaxies. 00:11:21.870 --> 00:11:21.880 align:start position:0% large concentration of galaxies. 00:11:21.880 --> 00:11:24.310 align:start position:0% large concentration of galaxies. I<00:11:22.000> hope<00:11:22.560> all<00:11:22.720> this<00:11:23.000> motion<00:11:23.520> isn't<00:11:23.800> making<00:11:24.160> you 00:11:24.310 --> 00:11:24.320 align:start position:0% I hope all this motion isn't making you 00:11:24.320 --> 00:11:25.829 align:start position:0% I hope all this motion isn't making you too<00:11:24.520> dizzy. 00:11:25.829 --> 00:11:25.839 align:start position:0% too dizzy. 00:11:25.839 --> 00:11:28.510 align:start position:0% too dizzy. But<00:11:26.680> on<00:11:26.839> the<00:11:26.920> grandest<00:11:27.600> scales<00:11:28.160> of<00:11:28.320> our 00:11:28.510 --> 00:11:28.520 align:start position:0% But on the grandest scales of our 00:11:28.520 --> 00:11:31.070 align:start position:0% But on the grandest scales of our universe,<00:11:29.520> something<00:11:30.040> strange<00:11:30.880> is 00:11:31.070 --> 00:11:31.080 align:start position:0% universe, something strange is 00:11:31.080 --> 00:11:32.470 align:start position:0% universe, something strange is happening. 00:11:32.470 --> 00:11:32.480 align:start position:0% happening. 00:11:32.480 --> 00:11:34.190 align:start position:0% happening. Scientists<00:11:32.960> have<00:11:33.120> begun<00:11:33.480> to<00:11:33.640> realize<00:11:34.080> that 00:11:34.190 --> 00:11:34.200 align:start position:0% Scientists have begun to realize that 00:11:34.200 --> 00:11:36.350 align:start position:0% Scientists have begun to realize that there<00:11:34.400> is<00:11:34.560> not<00:11:35.000> enough<00:11:35.360> mass<00:11:35.720> in<00:11:35.840> the<00:11:35.960> Shapley 00:11:36.350 --> 00:11:36.360 align:start position:0% there is not enough mass in the Shapley 00:11:36.360 --> 00:11:38.910 align:start position:0% there is not enough mass in the Shapley Supercluster<00:11:37.440> to<00:11:37.600> pull<00:11:37.920> us<00:11:38.080> towards<00:11:38.600> it<00:11:38.800> at 00:11:38.910 --> 00:11:38.920 align:start position:0% Supercluster to pull us towards it at 00:11:38.920 --> 00:11:40.710 align:start position:0% Supercluster to pull us towards it at the<00:11:39.040> rate<00:11:39.360> that<00:11:39.480> we<00:11:39.640> see. 00:11:40.710 --> 00:11:40.720 align:start position:0% the rate that we see. 00:11:40.720 --> 00:11:43.030 align:start position:0% the rate that we see. About<00:11:41.440> 50% 00:11:43.030 --> 00:11:43.040 align:start position:0% About 50% 00:11:43.040 --> 00:11:44.830 align:start position:0% About 50% of<00:11:43.200> the<00:11:43.280> cause<00:11:43.680> of<00:11:43.760> that<00:11:43.960> motion<00:11:44.560> is 00:11:44.830 --> 00:11:44.840 align:start position:0% of the cause of that motion is 00:11:44.840 --> 00:11:46.630 align:start position:0% of the cause of that motion is unaccounted<00:11:45.520> for. 00:11:46.630 --> 00:11:46.640 align:start position:0% unaccounted for. 00:11:46.640 --> 00:11:49.550 align:start position:0% unaccounted for. In<00:11:46.760> 2017,<00:11:48.040> researchers<00:11:48.680> discovered<00:11:49.440> a 00:11:49.550 --> 00:11:49.560 align:start position:0% In 2017, researchers discovered a 00:11:49.560 --> 00:11:51.670 align:start position:0% In 2017, researchers discovered a possible<00:11:50.120> source<00:11:50.880> for<00:11:51.000> the<00:11:51.120> rest<00:11:51.400> of<00:11:51.480> that 00:11:51.670 --> 00:11:51.680 align:start position:0% possible source for the rest of that 00:11:51.680 --> 00:11:52.950 align:start position:0% possible source for the rest of that motion. 00:11:52.950 --> 00:11:52.960 align:start position:0% motion. 00:11:52.960 --> 00:11:55.150 align:start position:0% motion. But<00:11:53.080> it's<00:11:53.200> not<00:11:53.400> something<00:11:53.800> pulling<00:11:54.240> us. 00:11:55.150 --> 00:11:55.160 align:start position:0% But it's not something pulling us. 00:11:55.160 --> 00:11:58.310 align:start position:0% But it's not something pulling us. It's<00:11:55.480> something<00:11:56.240> pushing. 00:11:58.310 --> 00:11:58.320 align:start position:0% It's something pushing. 00:11:58.320 --> 00:12:00.710 align:start position:0% It's something pushing. I'm<00:11:58.720> Alex<00:11:59.040> McConaughey<00:11:59.960> and<00:12:00.160> you're<00:12:00.320> watching 00:12:00.710 --> 00:12:00.720 align:start position:0% I'm Alex McConaughey and you're watching 00:12:00.720 --> 00:12:03.830 align:start position:0% I'm Alex McConaughey and you're watching Astrium.<00:12:01.760> Join<00:12:02.040> with<00:12:02.240> me<00:12:02.360> today<00:12:03.200> as<00:12:03.520> we 00:12:03.830 --> 00:12:03.840 align:start position:0% Astrium. Join with me today as we 00:12:03.840 --> 00:12:05.950 align:start position:0% Astrium. Join with me today as we explore<00:12:04.400> the<00:12:04.640> evidence<00:12:05.240> for<00:12:05.360> the<00:12:05.480> region<00:12:05.840> of 00:12:05.950 --> 00:12:05.960 align:start position:0% explore the evidence for the region of 00:12:05.960 --> 00:12:09.350 align:start position:0% explore the evidence for the region of space<00:12:06.440> known<00:12:06.960> as<00:12:07.120> the<00:12:07.280> Dipole<00:12:08.080> Repeller<00:12:09.200> and 00:12:09.350 --> 00:12:09.360 align:start position:0% space known as the Dipole Repeller and 00:12:09.360 --> 00:12:11.910 align:start position:0% space known as the Dipole Repeller and try<00:12:09.560> to<00:12:09.680> understand<00:12:10.280> how<00:12:11.040> in<00:12:11.160> a<00:12:11.240> universe 00:12:11.910 --> 00:12:11.920 align:start position:0% try to understand how in a universe 00:12:11.920 --> 00:12:15.030 align:start position:0% try to understand how in a universe filled<00:12:12.320> with<00:12:12.520> gravity<00:12:13.920> something<00:12:14.440> can<00:12:14.640> push 00:12:15.030 --> 00:12:15.040 align:start position:0% filled with gravity something can push 00:12:15.040 --> 00:12:19.270 align:start position:0% filled with gravity something can push us<00:12:15.640> instead<00:12:16.320> of<00:12:16.520> pull. 00:12:19.270 --> 00:12:19.280 align:start position:0% 00:12:19.280 --> 00:12:21.790 align:start position:0% Let's<00:12:19.480> start<00:12:19.800> with<00:12:19.960> a<00:12:20.000> little<00:12:20.400> context. 00:12:21.790 --> 00:12:21.800 align:start position:0% Let's start with a little context. 00:12:21.800 --> 00:12:23.750 align:start position:0% Let's start with a little context. It's<00:12:21.960> taken<00:12:22.320> a<00:12:22.400> long<00:12:22.760> time<00:12:23.080> for<00:12:23.200> astronomers 00:12:23.750 --> 00:12:23.760 align:start position:0% It's taken a long time for astronomers 00:12:23.760 --> 00:12:25.950 align:start position:0% It's taken a long time for astronomers to<00:12:23.880> recognize<00:12:24.480> that<00:12:24.680> this<00:12:25.000> motion<00:12:25.440> was<00:12:25.560> taking 00:12:25.950 --> 00:12:25.960 align:start position:0% to recognize that this motion was taking 00:12:25.960 --> 00:12:27.030 align:start position:0% to recognize that this motion was taking place. 00:12:27.030 --> 00:12:27.040 align:start position:0% place. 00:12:27.040 --> 00:12:28.870 align:start position:0% place. To<00:12:27.120> understand<00:12:27.720> that<00:12:27.840> we<00:12:28.000> were<00:12:28.160> moving, 00:12:28.870 --> 00:12:28.880 align:start position:0% To understand that we were moving, 00:12:28.880 --> 00:12:31.030 align:start position:0% To understand that we were moving, scientists<00:12:29.440> first<00:12:29.800> had<00:12:30.000> to<00:12:30.080> make<00:12:30.360> a<00:12:30.440> map<00:12:30.920> of 00:12:31.030 --> 00:12:31.040 align:start position:0% scientists first had to make a map of 00:12:31.040 --> 00:12:33.270 align:start position:0% scientists first had to make a map of the<00:12:31.160> regions<00:12:31.600> of<00:12:31.720> space<00:12:32.040> around<00:12:32.440> us. 00:12:33.270 --> 00:12:33.280 align:start position:0% the regions of space around us. 00:12:33.280 --> 00:12:35.230 align:start position:0% the regions of space around us. And<00:12:33.400> although<00:12:33.720> we<00:12:34.080> as<00:12:34.240> a<00:12:34.280> species<00:12:34.880> have<00:12:35.000> been 00:12:35.230 --> 00:12:35.240 align:start position:0% And although we as a species have been 00:12:35.240 --> 00:12:36.990 align:start position:0% And although we as a species have been mapping<00:12:35.640> the<00:12:35.720> stars<00:12:36.120> since<00:12:36.360> the<00:12:36.440> beginnings 00:12:36.990 --> 00:12:37.000 align:start position:0% mapping the stars since the beginnings 00:12:37.000 --> 00:12:39.350 align:start position:0% mapping the stars since the beginnings of<00:12:37.120> civilization,<00:12:38.400> it<00:12:38.520> was<00:12:38.640> only<00:12:38.880> thanks<00:12:39.200> to 00:12:39.350 --> 00:12:39.360 align:start position:0% of civilization, it was only thanks to 00:12:39.360 --> 00:12:43.230 align:start position:0% of civilization, it was only thanks to Mr.<00:12:39.720> Hubble<00:12:40.200> in<00:12:40.320> 1924<00:12:41.760> that<00:12:41.920> we<00:12:42.080> proved<00:12:42.920> there 00:12:43.230 --> 00:12:43.240 align:start position:0% Mr. Hubble in 1924 that we proved there 00:12:43.240 --> 00:12:46.030 align:start position:0% Mr. Hubble in 1924 that we proved there are<00:12:43.720> actually<00:12:44.200> stars<00:12:44.839> in<00:12:45.120> other<00:12:45.400> galaxies 00:12:46.030 --> 00:12:46.040 align:start position:0% are actually stars in other galaxies 00:12:46.040 --> 00:12:47.950 align:start position:0% are actually stars in other galaxies outside<00:12:46.480> the<00:12:46.560> Milky<00:12:46.920> Way. 00:12:47.950 --> 00:12:47.960 align:start position:0% outside the Milky Way. 00:12:47.960 --> 00:12:50.070 align:start position:0% outside the Milky Way. Before<00:12:48.320> then,<00:12:48.960> although<00:12:49.240> astronomers<00:12:49.839> had 00:12:50.070 --> 00:12:50.080 align:start position:0% Before then, although astronomers had 00:12:50.080 --> 00:12:51.910 align:start position:0% Before then, although astronomers had seen<00:12:50.288> [music]<00:12:50.680> fuzzy<00:12:51.040> little<00:12:51.360> clusters<00:12:51.800> of 00:12:51.910 --> 00:12:51.920 align:start position:0% seen [music] fuzzy little clusters of 00:12:51.920 --> 00:12:54.030 align:start position:0% seen [music] fuzzy little clusters of light<00:12:52.200> in<00:12:52.280> the<00:12:52.360> night<00:12:52.560> sky<00:12:53.000> that<00:12:53.200> we<00:12:53.360> now<00:12:53.760> know 00:12:54.030 --> 00:12:54.040 align:start position:0% light in the night sky that we now know 00:12:54.040 --> 00:12:56.550 align:start position:0% light in the night sky that we now know to<00:12:54.160> be<00:12:54.320> galaxies,<00:12:55.560> the<00:12:55.600> common<00:12:55.920> wisdom<00:12:56.280> was 00:12:56.550 --> 00:12:56.560 align:start position:0% to be galaxies, the common wisdom was 00:12:56.560 --> 00:12:58.630 align:start position:0% to be galaxies, the common wisdom was that<00:12:56.680> these<00:12:56.920> were<00:12:57.040> gas<00:12:57.360> cloud<00:12:57.720> spiral<00:12:58.120> nebula 00:12:58.630 --> 00:12:58.640 align:start position:0% that these were gas cloud spiral nebula 00:12:58.640 --> 00:13:01.070 align:start position:0% that these were gas cloud spiral nebula within<00:12:58.920> the<00:12:58.960> Milky<00:12:59.240> Way,<00:13:00.040> not<00:13:00.400> something<00:13:00.920> that 00:13:01.070 --> 00:13:01.080 align:start position:0% within the Milky Way, not something that 00:13:01.080 --> 00:13:03.310 align:start position:0% within the Milky Way, not something that existed<00:13:01.600> beyond<00:13:01.960> it. 00:13:03.310 --> 00:13:03.320 align:start position:0% existed beyond it. 00:13:03.320 --> 00:13:06.390 align:start position:0% existed beyond it. Hubble<00:13:03.960> noticed<00:13:04.520> several<00:13:04.920> Cepheid<00:13:05.320> stars,<00:13:06.320> a 00:13:06.390 --> 00:13:06.400 align:start position:0% Hubble noticed several Cepheid stars, a 00:13:06.400 --> 00:13:08.350 align:start position:0% Hubble noticed several Cepheid stars, a type<00:13:06.680> of<00:13:06.839> variable<00:13:07.360> star<00:13:07.720> with<00:13:07.839> a<00:13:07.880> cycle<00:13:08.280> of 00:13:08.350 --> 00:13:08.360 align:start position:0% type of variable star with a cycle of 00:13:08.360 --> 00:13:09.990 align:start position:0% type of variable star with a cycle of variation<00:13:09.040> closely<00:13:09.520> linked<00:13:09.800> to<00:13:09.880> their 00:13:09.990 --> 00:13:10.000 align:start position:0% variation closely linked to their 00:13:10.000 --> 00:13:12.550 align:start position:0% variation closely linked to their luminosity,<00:13:11.120> within<00:13:11.839> one<00:13:12.200> such<00:13:12.559> [music] 00:13:12.550 --> 00:13:12.560 align:start position:0% luminosity, within one such [music] 00:13:12.560 --> 00:13:14.110 align:start position:0% luminosity, within one such [music] spiral<00:13:12.960> nebula, 00:13:14.110 --> 00:13:14.120 align:start position:0% spiral nebula, 00:13:14.120 --> 00:13:16.070 align:start position:0% spiral nebula, and<00:13:14.320> used<00:13:14.560> the<00:13:14.640> fact<00:13:15.000> that<00:13:15.120> this<00:13:15.360> luminosity 00:13:16.070 --> 00:13:16.080 align:start position:0% and used the fact that this luminosity 00:13:16.080 --> 00:13:18.829 align:start position:0% and used the fact that this luminosity was<00:13:16.320> very<00:13:16.760> predictable<00:13:17.560> based<00:13:17.960> on<00:13:18.160> distance 00:13:18.829 --> 00:13:18.839 align:start position:0% was very predictable based on distance 00:13:18.839 --> 00:13:21.630 align:start position:0% was very predictable based on distance to<00:13:19.000> calculate<00:13:19.640> very<00:13:19.960> precisely<00:13:20.880> how<00:13:21.120> far<00:13:21.360> away 00:13:21.630 --> 00:13:21.640 align:start position:0% to calculate very precisely how far away 00:13:21.640 --> 00:13:22.870 align:start position:0% to calculate very precisely how far away they<00:13:21.839> were. 00:13:22.870 --> 00:13:22.880 align:start position:0% they were. 00:13:22.880 --> 00:13:26.230 align:start position:0% they were. Surprising<00:13:23.600> many,<00:13:24.440> he<00:13:24.640> proved<00:13:25.360> that<00:13:25.480> they<00:13:25.680> do 00:13:26.230 --> 00:13:26.240 align:start position:0% Surprising many, he proved that they do 00:13:26.240 --> 00:13:29.390 align:start position:0% Surprising many, he proved that they do exist<00:13:26.960> beyond<00:13:27.440> the<00:13:27.520> Milky<00:13:27.880> Way. 00:13:29.390 --> 00:13:29.400 align:start position:0% exist beyond the Milky Way. 00:13:29.400 --> 00:13:31.190 align:start position:0% exist beyond the Milky Way. Since<00:13:29.640> then,<00:13:30.200> astronomers<00:13:30.840> have<00:13:31.000> been 00:13:31.190 --> 00:13:31.200 align:start position:0% Since then, astronomers have been 00:13:31.200 --> 00:13:32.950 align:start position:0% Since then, astronomers have been scrambling<00:13:31.920> to<00:13:32.040> catch<00:13:32.360> up<00:13:32.480> with<00:13:32.640> the<00:13:32.720> new 00:13:32.950 --> 00:13:32.960 align:start position:0% scrambling to catch up with the new 00:13:32.960 --> 00:13:35.510 align:start position:0% scrambling to catch up with the new reality<00:13:33.440> of<00:13:33.600> galaxies<00:13:34.200> and<00:13:34.360> superclusters 00:13:35.510 --> 00:13:35.520 align:start position:0% reality of galaxies and superclusters 00:13:35.520 --> 00:13:37.990 align:start position:0% reality of galaxies and superclusters and<00:13:35.720> set<00:13:35.920> about<00:13:36.400> mapping<00:13:36.960> the<00:13:37.080> locations<00:13:37.840> and 00:13:37.990 --> 00:13:38.000 align:start position:0% and set about mapping the locations and 00:13:38.000 --> 00:13:40.030 align:start position:0% and set about mapping the locations and distances<00:13:38.640> to<00:13:38.840> every<00:13:39.200> galaxy<00:13:39.720> they<00:13:39.840> could 00:13:40.030 --> 00:13:40.040 align:start position:0% distances to every galaxy they could 00:13:40.040 --> 00:13:41.310 align:start position:0% distances to every galaxy they could find. 00:13:41.310 --> 00:13:41.320 align:start position:0% find. 00:13:41.320 --> 00:13:43.990 align:start position:0% find. Hubble<00:13:41.720> had<00:13:41.920> been<00:13:42.120> studying<00:13:42.680> Andromeda,<00:13:43.800> our 00:13:43.990 --> 00:13:44.000 align:start position:0% Hubble had been studying Andromeda, our 00:13:44.000 --> 00:13:46.710 align:start position:0% Hubble had been studying Andromeda, our closest<00:13:44.720> neighboring<00:13:45.240> major<00:13:45.560> galaxy,<00:13:46.600> but 00:13:46.710 --> 00:13:46.720 align:start position:0% closest neighboring major galaxy, but 00:13:46.720 --> 00:13:48.430 align:start position:0% closest neighboring major galaxy, but there<00:13:46.880> were<00:13:47.200> others. 00:13:48.430 --> 00:13:48.440 align:start position:0% there were others. 00:13:48.440 --> 00:13:51.190 align:start position:0% there were others. By<00:13:48.520> the<00:13:48.640> 1970s,<00:13:50.000> Stephen<00:13:50.400> Gregory,<00:13:50.960> Laird 00:13:51.190 --> 00:13:51.200 align:start position:0% By the 1970s, Stephen Gregory, Laird 00:13:51.200 --> 00:13:54.750 align:start position:0% By the 1970s, Stephen Gregory, Laird Thompson,<00:13:52.240> and<00:13:52.480> William<00:13:52.920> Tifft<00:13:53.840> definitively 00:13:54.750 --> 00:13:54.760 align:start position:0% Thompson, and William Tifft definitively 00:13:54.760 --> 00:13:57.190 align:start position:0% Thompson, and William Tifft definitively proved<00:13:55.200> that<00:13:55.320> galaxies<00:13:56.000> didn't<00:13:56.480> just<00:13:56.840> float 00:13:57.190 --> 00:13:57.200 align:start position:0% proved that galaxies didn't just float 00:13:57.200 --> 00:14:00.030 align:start position:0% proved that galaxies didn't just float randomly<00:13:57.680> in<00:13:57.840> space,<00:13:58.800> but<00:13:58.960> converged<00:13:59.760> into 00:14:00.030 --> 00:14:00.040 align:start position:0% randomly in space, but converged into 00:14:00.040 --> 00:14:03.230 align:start position:0% randomly in space, but converged into superclusters,<00:14:01.440> large<00:14:02.000> filamentary<00:14:03.000> or 00:14:03.230 --> 00:14:03.240 align:start position:0% superclusters, large filamentary or 00:14:03.240 --> 00:14:05.550 align:start position:0% superclusters, large filamentary or sheet-like<00:14:03.920> structures<00:14:04.560> that<00:14:04.680> exist<00:14:05.160> between 00:14:05.550 --> 00:14:05.560 align:start position:0% sheet-like structures that exist between 00:14:05.560 --> 00:14:08.350 align:start position:0% sheet-like structures that exist between large<00:14:05.960> bubbles<00:14:06.400> of<00:14:06.520> void.<00:14:07.520> They<00:14:07.680> mapped<00:14:08.240> the 00:14:08.350 --> 00:14:08.360 align:start position:0% large bubbles of void. They mapped the 00:14:08.360 --> 00:14:10.470 align:start position:0% large bubbles of void. They mapped the first<00:14:08.680> supercluster,<00:14:09.800> the<00:14:09.920> Coma 00:14:10.470 --> 00:14:10.480 align:start position:0% first supercluster, the Coma 00:14:10.480 --> 00:14:12.870 align:start position:0% first supercluster, the Coma Supercluster,<00:14:11.720> which<00:14:11.960> covered<00:14:12.320> a<00:14:12.400> region<00:14:12.760> of 00:14:12.870 --> 00:14:12.880 align:start position:0% Supercluster, which covered a region of 00:14:12.880 --> 00:14:13.464 align:start position:0% Supercluster, which covered a region of space 00:14:13.464 --> 00:14:13.474 align:start position:0% space 00:14:13.474 --> 00:14:13.670 align:start position:0% space >> [music] 00:14:13.670 --> 00:14:13.680 align:start position:0% >> [music] 00:14:13.680 --> 00:14:16.910 align:start position:0% >> [music] >> 100<00:14:14.640> million<00:14:15.280> light-years<00:14:15.800> across. 00:14:16.910 --> 00:14:16.920 align:start position:0% >> 100 million light-years across. 00:14:16.920 --> 00:14:19.630 align:start position:0% >> 100 million light-years across. A<00:14:17.000> whopping<00:14:17.840> 95% 00:14:19.630 --> 00:14:19.640 align:start position:0% A whopping 95% 00:14:19.640 --> 00:14:23.270 align:start position:0% A whopping 95% of<00:14:20.000> all<00:14:20.520> galaxies<00:14:21.560> are<00:14:21.720> found<00:14:22.520> in<00:14:22.760> these 00:14:23.270 --> 00:14:23.280 align:start position:0% of all galaxies are found in these 00:14:23.280 --> 00:14:25.110 align:start position:0% of all galaxies are found in these superstructures. 00:14:25.110 --> 00:14:25.120 align:start position:0% superstructures. 00:14:25.120 --> 00:14:27.430 align:start position:0% superstructures. It<00:14:25.240> wasn't<00:14:25.560> until<00:14:25.920> 2014 00:14:27.430 --> 00:14:27.440 align:start position:0% It wasn't until 2014 00:14:27.440 --> 00:14:30.390 align:start position:0% It wasn't until 2014 that<00:14:27.600> our<00:14:27.880> own<00:14:28.120> supercluster,<00:14:29.320> the<00:14:29.440> Laniakea 00:14:30.390 --> 00:14:30.400 align:start position:0% that our own supercluster, the Laniakea 00:14:30.400 --> 00:14:33.510 align:start position:0% that our own supercluster, the Laniakea Supercluster,<00:14:31.720> was<00:14:31.960> fully<00:14:32.200> mapped. 00:14:33.510 --> 00:14:33.520 align:start position:0% Supercluster, was fully mapped. 00:14:33.520 --> 00:14:35.070 align:start position:0% Supercluster, was fully mapped. You<00:14:33.560> might<00:14:33.800> be<00:14:33.960> surprised<00:14:34.640> to<00:14:34.720> hear<00:14:34.960> it 00:14:35.070 --> 00:14:35.080 align:start position:0% You might be surprised to hear it 00:14:35.080 --> 00:14:37.710 align:start position:0% You might be surprised to hear it happened<00:14:35.440> in<00:14:35.560> that<00:14:35.800> order.<00:14:36.760> After<00:14:37.120> all, 00:14:37.710 --> 00:14:37.720 align:start position:0% happened in that order. After all, 00:14:37.720 --> 00:14:39.950 align:start position:0% happened in that order. After all, wouldn't<00:14:38.040> common<00:14:38.360> sense<00:14:38.680> say<00:14:39.040> it's<00:14:39.360> easier<00:14:39.800> to 00:14:39.950 --> 00:14:39.960 align:start position:0% wouldn't common sense say it's easier to 00:14:39.960 --> 00:14:42.829 align:start position:0% wouldn't common sense say it's easier to map<00:14:40.320> regions<00:14:40.760> of<00:14:40.880> space<00:14:41.320> closer<00:14:41.800> to<00:14:41.960> us<00:14:42.520> rather 00:14:42.829 --> 00:14:42.839 align:start position:0% map regions of space closer to us rather 00:14:42.839 --> 00:14:45.110 align:start position:0% map regions of space closer to us rather than<00:14:43.040> ones<00:14:43.480> further<00:14:43.880> away? 00:14:45.110 --> 00:14:45.120 align:start position:0% than ones further away? 00:14:45.120 --> 00:14:47.630 align:start position:0% than ones further away? Why<00:14:45.320> was<00:14:45.520> it<00:14:45.680> only<00:14:45.920> nearly<00:14:46.280> a<00:14:46.360> century<00:14:47.160> after 00:14:47.630 --> 00:14:47.640 align:start position:0% Why was it only nearly a century after 00:14:47.640 --> 00:14:50.145 align:start position:0% Why was it only nearly a century after the<00:14:47.760> discovery<00:14:48.320> of<00:14:48.480> other<00:14:48.720> galaxies<00:14:49.280> existing 00:14:50.145 --> 00:14:50.155 align:start position:0% the discovery of other galaxies existing 00:14:50.155 --> 00:14:50.230 align:start position:0% the discovery of other galaxies existing >> [music] 00:14:50.230 --> 00:14:50.240 align:start position:0% >> [music] 00:14:50.240 --> 00:14:52.390 align:start position:0% >> [music] >> and<00:14:50.440> 40<00:14:50.800> years<00:14:51.080> after<00:14:51.480> mapping<00:14:51.920> the<00:14:52.040> first 00:14:52.390 --> 00:14:52.400 align:start position:0% >> and 40 years after mapping the first 00:14:52.400 --> 00:14:54.790 align:start position:0% >> and 40 years after mapping the first supercluster<00:14:53.480> that<00:14:53.600> we<00:14:53.760> finally<00:14:54.200> turned<00:14:54.680> to 00:14:54.790 --> 00:14:54.800 align:start position:0% supercluster that we finally turned to 00:14:54.800 --> 00:14:56.750 align:start position:0% supercluster that we finally turned to our<00:14:55.120> own? 00:14:56.750 --> 00:14:56.760 align:start position:0% our own? 00:14:56.760 --> 00:14:59.310 align:start position:0% our own? The<00:14:56.839> answer<00:14:57.320> is<00:14:57.760> that<00:14:58.240> mapping<00:14:58.839> the<00:14:58.960> local 00:14:59.310 --> 00:14:59.320 align:start position:0% The answer is that mapping the local 00:14:59.320 --> 00:15:01.550 align:start position:0% The answer is that mapping the local regions<00:14:59.720> of<00:14:59.839> space<00:15:00.120> around<00:15:00.520> us<00:15:01.000> is 00:15:01.550 --> 00:15:01.560 align:start position:0% regions of space around us is 00:15:01.560 --> 00:15:03.550 align:start position:0% regions of space around us is surprisingly<00:15:01.945> [music]<00:15:02.320> challenging. 00:15:03.550 --> 00:15:03.560 align:start position:0% surprisingly [music] challenging. 00:15:03.560 --> 00:15:05.750 align:start position:0% surprisingly [music] challenging. And<00:15:03.680> it's<00:15:03.839> all<00:15:04.040> because<00:15:04.560> of<00:15:04.680> the<00:15:04.800> Milky<00:15:05.200> Way 00:15:05.750 --> 00:15:05.760 align:start position:0% And it's all because of the Milky Way 00:15:05.760 --> 00:15:10.430 align:start position:0% And it's all because of the Milky Way getting<00:15:06.160> in<00:15:06.760> the<00:15:07.040> Milky<00:15:07.400> Way. 00:15:10.430 --> 00:15:10.440 align:start position:0% 00:15:10.440 --> 00:15:13.950 align:start position:0% The<00:15:10.520> Milky<00:15:10.800> Way<00:15:11.200> is<00:15:11.520> full<00:15:12.040> of<00:15:12.320> gas<00:15:12.839> and<00:15:13.040> dust, 00:15:13.950 --> 00:15:13.960 align:start position:0% The Milky Way is full of gas and dust, 00:15:13.960 --> 00:15:16.150 align:start position:0% The Milky Way is full of gas and dust, and<00:15:14.040> these<00:15:14.280> regions<00:15:14.760> are<00:15:14.920> so<00:15:15.480> difficult<00:15:16.080> to 00:15:16.150 --> 00:15:16.160 align:start position:0% and these regions are so difficult to 00:15:16.160 --> 00:15:17.110 align:start position:0% and these regions are so difficult to penetrate<00:15:16.355> [music] 00:15:17.110 --> 00:15:17.120 align:start position:0% penetrate [music] 00:15:17.120 --> 00:15:20.190 align:start position:0% penetrate [music] that<00:15:17.240> we<00:15:17.400> can't<00:15:18.080> really<00:15:18.560> see<00:15:18.800> beyond<00:15:19.160> them. 00:15:20.190 --> 00:15:20.200 align:start position:0% that we can't really see beyond them. 00:15:20.200 --> 00:15:21.990 align:start position:0% that we can't really see beyond them. Towards<00:15:20.520> the<00:15:20.600> center<00:15:21.000> of<00:15:21.080> the<00:15:21.160> Milky<00:15:21.480> Way, 00:15:21.990 --> 00:15:22.000 align:start position:0% Towards the center of the Milky Way, 00:15:22.000 --> 00:15:24.205 align:start position:0% Towards the center of the Milky Way, this<00:15:22.200> effect<00:15:22.640> gets<00:15:22.960> so<00:15:23.280> bad<00:15:23.920> that<00:15:24.080> scientists 00:15:24.205 --> 00:15:24.215 align:start position:0% this effect gets so bad that scientists 00:15:24.215 --> 00:15:26.590 align:start position:0% this effect gets so bad that scientists [music]<00:15:24.560> have<00:15:24.800> dubbed<00:15:25.120> the<00:15:25.240> whole<00:15:25.680> area<00:15:26.480> the 00:15:26.590 --> 00:15:26.600 align:start position:0% [music] have dubbed the whole area the 00:15:26.600 --> 00:15:28.470 align:start position:0% [music] have dubbed the whole area the zone<00:15:27.080> of<00:15:27.240> avoidance. 00:15:28.470 --> 00:15:28.480 align:start position:0% zone of avoidance. 00:15:28.480 --> 00:15:31.070 align:start position:0% zone of avoidance. Very<00:15:28.920> little<00:15:29.240> light<00:15:29.520> gets<00:15:29.760> through<00:15:30.000> it. 00:15:31.070 --> 00:15:31.080 align:start position:0% Very little light gets through it. 00:15:31.080 --> 00:15:33.030 align:start position:0% Very little light gets through it. Not<00:15:31.320> being<00:15:31.560> able<00:15:31.720> to<00:15:31.840> see<00:15:32.080> in<00:15:32.200> this<00:15:32.400> area<00:15:32.840> is 00:15:33.030 --> 00:15:33.040 align:start position:0% Not being able to see in this area is 00:15:33.040 --> 00:15:34.790 align:start position:0% Not being able to see in this area is particularly<00:15:33.840> relevant<00:15:34.320> to<00:15:34.440> our<00:15:34.560> current 00:15:34.790 --> 00:15:34.800 align:start position:0% particularly relevant to our current 00:15:34.800 --> 00:15:36.510 align:start position:0% particularly relevant to our current discussion<00:15:35.520> for<00:15:35.680> reasons<00:15:36.040> we'll<00:15:36.200> get<00:15:36.400> to 00:15:36.510 --> 00:15:36.520 align:start position:0% discussion for reasons we'll get to 00:15:36.520 --> 00:15:37.950 align:start position:0% discussion for reasons we'll get to later. 00:15:37.950 --> 00:15:37.960 align:start position:0% later. 00:15:37.960 --> 00:15:40.790 align:start position:0% later. In<00:15:38.400> contrast<00:15:38.960> to<00:15:39.080> our<00:15:39.200> local<00:15:39.600> area,<00:15:40.480> distant 00:15:40.790 --> 00:15:40.800 align:start position:0% In contrast to our local area, distant 00:15:40.800 --> 00:15:43.230 align:start position:0% In contrast to our local area, distant galaxies<00:15:41.400> are<00:15:41.680> easier<00:15:42.000> to<00:15:42.120> study<00:15:42.800> as<00:15:42.960> all<00:15:43.120> you 00:15:43.230 --> 00:15:43.240 align:start position:0% galaxies are easier to study as all you 00:15:43.240 --> 00:15:45.190 align:start position:0% galaxies are easier to study as all you have<00:15:43.440> to<00:15:43.520> do<00:15:43.840> is<00:15:44.000> point<00:15:44.240> your<00:15:44.360> telescope<00:15:45.040> at<00:15:45.160> a 00:15:45.190 --> 00:15:45.200 align:start position:0% have to do is point your telescope at a 00:15:45.200 --> 00:15:47.430 align:start position:0% have to do is point your telescope at a single<00:15:45.560> point<00:15:45.840> in<00:15:45.920> the<00:15:45.960> night<00:15:46.200> sky<00:15:46.920> and<00:15:47.120> let<00:15:47.320> it 00:15:47.430 --> 00:15:47.440 align:start position:0% single point in the night sky and let it 00:15:47.440 --> 00:15:50.030 align:start position:0% single point in the night sky and let it drink<00:15:47.760> in<00:15:47.920> the<00:15:48.040> light.<00:15:49.000> Mapping<00:15:49.400> the<00:15:49.520> area 00:15:50.030 --> 00:15:50.040 align:start position:0% drink in the light. Mapping the area 00:15:50.040 --> 00:15:53.150 align:start position:0% drink in the light. Mapping the area around<00:15:50.640> us<00:15:51.440> requires<00:15:52.000> looking<00:15:52.360> at<00:15:52.680> every 00:15:53.150 --> 00:15:53.160 align:start position:0% around us requires looking at every 00:15:53.160 --> 00:15:55.510 align:start position:0% around us requires looking at every point<00:15:53.680> in<00:15:53.840> the<00:15:53.960> night<00:15:54.200> sky. 00:15:55.510 --> 00:15:55.520 align:start position:0% point in the night sky. 00:15:55.520 --> 00:15:57.990 align:start position:0% point in the night sky. It's<00:15:55.960> proved<00:15:56.600> quite<00:15:56.840> difficult,<00:15:57.720> although 00:15:57.990 --> 00:15:58.000 align:start position:0% It's proved quite difficult, although 00:15:58.000 --> 00:15:59.830 align:start position:0% It's proved quite difficult, although astronomers<00:15:58.680> are<00:15:58.800> now<00:15:59.120> getting<00:15:59.440> a<00:15:59.520> better 00:15:59.830 --> 00:15:59.840 align:start position:0% astronomers are now getting a better 00:15:59.840 --> 00:16:02.390 align:start position:0% astronomers are now getting a better handle<00:16:00.200> on<00:16:00.360> it.<00:16:01.080> Thanks<00:16:01.440> to<00:16:01.560> their<00:16:01.800> efforts<00:16:02.160> in 00:16:02.390 --> 00:16:02.400 align:start position:0% handle on it. Thanks to their efforts in 00:16:02.400 --> 00:16:04.350 align:start position:0% handle on it. Thanks to their efforts in looking<00:16:02.680> at<00:16:02.880> thousands<00:16:03.400> of<00:16:03.520> galaxies<00:16:04.080> in<00:16:04.200> our 00:16:04.350 --> 00:16:04.360 align:start position:0% looking at thousands of galaxies in our 00:16:04.360 --> 00:16:06.470 align:start position:0% looking at thousands of galaxies in our galactic<00:16:04.800> neighborhood<00:16:05.760> and<00:16:05.920> by<00:16:06.040> studying 00:16:06.470 --> 00:16:06.480 align:start position:0% galactic neighborhood and by studying 00:16:06.480 --> 00:16:09.510 align:start position:0% galactic neighborhood and by studying galaxies'<00:16:07.200> peculiar<00:16:07.920> motion<00:16:08.920> or<00:16:09.240> their 00:16:09.510 --> 00:16:09.520 align:start position:0% galaxies' peculiar motion or their 00:16:09.520 --> 00:16:11.870 align:start position:0% galaxies' peculiar motion or their motion<00:16:10.160> relative<00:16:10.760> to<00:16:10.880> the<00:16:10.960> cosmic<00:16:11.360> background 00:16:11.870 --> 00:16:11.880 align:start position:0% motion relative to the cosmic background 00:16:11.880 --> 00:16:14.350 align:start position:0% motion relative to the cosmic background radiation<00:16:12.720> that<00:16:13.160> ignores<00:16:13.720> the<00:16:13.840> expansion<00:16:14.280> of 00:16:14.350 --> 00:16:14.360 align:start position:0% radiation that ignores the expansion of 00:16:14.360 --> 00:16:15.750 align:start position:0% radiation that ignores the expansion of the<00:16:14.480> universe, 00:16:15.750 --> 00:16:15.760 align:start position:0% the universe, 00:16:15.760 --> 00:16:17.470 align:start position:0% the universe, scientists<00:16:16.400> have<00:16:16.560> been<00:16:16.760> able<00:16:16.920> to<00:16:17.040> group 00:16:17.470 --> 00:16:17.480 align:start position:0% scientists have been able to group 00:16:17.480 --> 00:16:20.150 align:start position:0% scientists have been able to group gravitationally<00:16:18.400> bound<00:16:18.880> galaxies<00:16:19.520> into 00:16:20.150 --> 00:16:20.160 align:start position:0% gravitationally bound galaxies into 00:16:20.160 --> 00:16:21.710 align:start position:0% gravitationally bound galaxies into superclusters. 00:16:21.710 --> 00:16:21.720 align:start position:0% superclusters. 00:16:21.720 --> 00:16:23.870 align:start position:0% superclusters. At<00:16:21.880> the<00:16:21.960> center<00:16:22.440> of<00:16:22.680> our<00:16:22.960> Laniakea 00:16:23.870 --> 00:16:23.880 align:start position:0% At the center of our Laniakea 00:16:23.880 --> 00:16:26.590 align:start position:0% At the center of our Laniakea Supercluster,<00:16:24.960> lies<00:16:25.200> a<00:16:25.280> point<00:16:25.760> known<00:16:26.240> as<00:16:26.480> the 00:16:26.590 --> 00:16:26.600 align:start position:0% Supercluster, lies a point known as the 00:16:26.600 --> 00:16:30.670 align:start position:0% Supercluster, lies a point known as the Great<00:16:27.000> Attractor,<00:16:28.160> an<00:16:28.360> area<00:16:28.760> 150<00:16:29.760> to<00:16:29.920> 250 00:16:30.670 --> 00:16:30.680 align:start position:0% Great Attractor, an area 150 to 250 00:16:30.680 --> 00:16:32.870 align:start position:0% Great Attractor, an area 150 to 250 million<00:16:31.200> light-years<00:16:31.600> away<00:16:31.839> from<00:16:32.080> us<00:16:32.640> that 00:16:32.870 --> 00:16:32.880 align:start position:0% million light-years away from us that 00:16:32.880 --> 00:16:35.230 align:start position:0% million light-years away from us that we,<00:16:33.360> in<00:16:33.480> the<00:16:33.560> Milky<00:16:33.839> Way,<00:16:34.520> are<00:16:34.640> slowly 00:16:35.230 --> 00:16:35.240 align:start position:0% we, in the Milky Way, are slowly 00:16:35.240 --> 00:16:36.910 align:start position:0% we, in the Milky Way, are slowly drifting<00:16:35.640> towards. 00:16:36.910 --> 00:16:36.920 align:start position:0% drifting towards. 00:16:36.920 --> 00:16:39.230 align:start position:0% drifting towards. Sadly,<00:16:37.680> the<00:16:37.800> Great<00:16:38.040> Attractor<00:16:38.560> lies<00:16:38.920> within 00:16:39.230 --> 00:16:39.240 align:start position:0% Sadly, the Great Attractor lies within 00:16:39.240 --> 00:16:41.510 align:start position:0% Sadly, the Great Attractor lies within the<00:16:39.360> zone<00:16:39.600> of<00:16:39.720> avoidance,<00:16:40.720> so<00:16:40.839> it's<00:16:41.000> tricky<00:16:41.360> to 00:16:41.510 --> 00:16:41.520 align:start position:0% the zone of avoidance, so it's tricky to 00:16:41.520 --> 00:16:44.470 align:start position:0% the zone of avoidance, so it's tricky to see<00:16:41.760> clearly<00:16:42.680> what<00:16:42.920> lies<00:16:43.240> there. 00:16:44.470 --> 00:16:44.480 align:start position:0% see clearly what lies there. 00:16:44.480 --> 00:16:47.430 align:start position:0% see clearly what lies there. To<00:16:44.640> confound<00:16:45.120> things<00:16:45.480> further,<00:16:46.320> the<00:16:46.600> Laniakea 00:16:47.430 --> 00:16:47.440 align:start position:0% To confound things further, the Laniakea 00:16:47.440 --> 00:16:49.630 align:start position:0% To confound things further, the Laniakea Supercluster<00:16:48.440> was<00:16:48.680> also<00:16:49.120> found<00:16:49.440> to<00:16:49.520> be 00:16:49.630 --> 00:16:49.640 align:start position:0% Supercluster was also found to be 00:16:49.640 --> 00:16:52.110 align:start position:0% Supercluster was also found to be moving.<00:16:50.520> It<00:16:50.720> travels<00:16:51.200> towards<00:16:51.680> another 00:16:52.110 --> 00:16:52.120 align:start position:0% moving. It travels towards another 00:16:52.120 --> 00:16:54.430 align:start position:0% moving. It travels towards another supercluster<00:16:53.200> known<00:16:53.520> as<00:16:53.760> the<00:16:53.880> Shapley 00:16:54.430 --> 00:16:54.440 align:start position:0% supercluster known as the Shapley 00:16:54.440 --> 00:16:57.990 align:start position:0% supercluster known as the Shapley Supercluster,<00:16:55.600> taking<00:16:55.960> us<00:16:56.400> along<00:16:56.760> with<00:16:56.960> it. 00:16:57.990 --> 00:16:58.000 align:start position:0% Supercluster, taking us along with it. 00:16:58.000 --> 00:17:00.150 align:start position:0% Supercluster, taking us along with it. At<00:16:58.160> the<00:16:58.240> center<00:16:58.640> of<00:16:58.760> this<00:16:59.000> supercluster<00:16:59.800> lies 00:17:00.150 --> 00:17:00.160 align:start position:0% At the center of this supercluster lies 00:17:00.160 --> 00:17:02.950 align:start position:0% At the center of this supercluster lies the<00:17:00.320> Shapley<00:17:00.839> Attractor,<00:17:01.920> which<00:17:02.200> also<00:17:02.760> is 00:17:02.950 --> 00:17:02.960 align:start position:0% the Shapley Attractor, which also is 00:17:02.960 --> 00:17:05.350 align:start position:0% the Shapley Attractor, which also is believed<00:17:03.320> to<00:17:03.400> be<00:17:03.520> incredibly<00:17:04.480> dense<00:17:04.880> in<00:17:05.000> terms 00:17:05.350 --> 00:17:05.360 align:start position:0% believed to be incredibly dense in terms 00:17:05.360 --> 00:17:06.510 align:start position:0% believed to be incredibly dense in terms of<00:17:05.480> mass. 00:17:06.510 --> 00:17:06.520 align:start position:0% of mass. 00:17:06.520 --> 00:17:08.990 align:start position:0% of mass. But,<00:17:07.040> frustratingly,<00:17:08.439> this<00:17:08.680> second 00:17:08.990 --> 00:17:09.000 align:start position:0% But, frustratingly, this second 00:17:09.000 --> 00:17:11.429 align:start position:0% But, frustratingly, this second attractor<00:17:09.760> also<00:17:10.280> lies<00:17:10.720> in<00:17:10.839> the<00:17:10.959> zone<00:17:11.280> of 00:17:11.429 --> 00:17:11.439 align:start position:0% attractor also lies in the zone of 00:17:11.439 --> 00:17:13.710 align:start position:0% attractor also lies in the zone of avoidance,<00:17:12.439> making<00:17:12.720> it<00:17:12.839> difficult<00:17:13.280> to<00:17:13.400> see 00:17:13.710 --> 00:17:13.720 align:start position:0% avoidance, making it difficult to see 00:17:13.720 --> 00:17:17.390 align:start position:0% avoidance, making it difficult to see exactly<00:17:14.560> what's<00:17:14.839> going<00:17:15.160> on<00:17:15.360> over<00:17:15.600> there,<00:17:15.839> too. 00:17:17.390 --> 00:17:17.400 align:start position:0% exactly what's going on over there, too. 00:17:17.400 --> 00:17:19.870 align:start position:0% exactly what's going on over there, too. Thankfully,<00:17:18.280> as<00:17:18.520> X-ray<00:17:19.120> and<00:17:19.400> infrared 00:17:19.870 --> 00:17:19.880 align:start position:0% Thankfully, as X-ray and infrared 00:17:19.880 --> 00:17:22.429 align:start position:0% Thankfully, as X-ray and infrared telescopes<00:17:20.439> improved,<00:17:21.439> it<00:17:21.560> became<00:17:21.880> possible 00:17:22.429 --> 00:17:22.439 align:start position:0% telescopes improved, it became possible 00:17:22.439 --> 00:17:24.230 align:start position:0% telescopes improved, it became possible to<00:17:22.560> take<00:17:22.880> a<00:17:23.000> better<00:17:23.520> look<00:17:23.760> at<00:17:23.880> these<00:17:24.079> two 00:17:24.230 --> 00:17:24.240 align:start position:0% to take a better look at these two 00:17:24.240 --> 00:17:25.790 align:start position:0% to take a better look at these two attractors. 00:17:25.790 --> 00:17:25.800 align:start position:0% attractors. 00:17:25.800 --> 00:17:28.470 align:start position:0% attractors. But,<00:17:26.040> this<00:17:26.280> is<00:17:26.439> where<00:17:26.640> the<00:17:26.720> mystery<00:17:27.079> begins. 00:17:28.470 --> 00:17:28.480 align:start position:0% But, this is where the mystery begins. 00:17:28.480 --> 00:17:31.630 align:start position:0% But, this is where the mystery begins. What<00:17:28.720> mass<00:17:29.280> is<00:17:29.680> there<00:17:30.480> is<00:17:30.680> not<00:17:30.920> quite<00:17:31.280> massive 00:17:31.630 --> 00:17:31.640 align:start position:0% What mass is there is not quite massive 00:17:31.640 --> 00:17:33.710 align:start position:0% What mass is there is not quite massive enough<00:17:32.080> to<00:17:32.200> account<00:17:32.600> for<00:17:32.840> our<00:17:33.080> apparent 00:17:33.710 --> 00:17:33.720 align:start position:0% enough to account for our apparent 00:17:33.720 --> 00:17:36.110 align:start position:0% enough to account for our apparent motion<00:17:34.320> in<00:17:34.480> that<00:17:34.640> direction, 00:17:36.110 --> 00:17:36.120 align:start position:0% motion in that direction, 00:17:36.120 --> 00:17:38.310 align:start position:0% motion in that direction, which<00:17:36.280> is<00:17:36.440> why<00:17:36.800> a<00:17:36.920> team<00:17:37.320> of<00:17:37.480> researchers<00:17:38.160> from 00:17:38.310 --> 00:17:38.320 align:start position:0% which is why a team of researchers from 00:17:38.320 --> 00:17:40.510 align:start position:0% which is why a team of researchers from the<00:17:38.400> University<00:17:39.040> of<00:17:39.160> Hawaii<00:17:39.920> published<00:17:40.360> an 00:17:40.510 --> 00:17:40.520 align:start position:0% the University of Hawaii published an 00:17:40.520 --> 00:17:43.110 align:start position:0% the University of Hawaii published an article<00:17:40.960> in<00:17:41.080> Nature<00:17:41.800> to<00:17:41.960> attempt<00:17:42.400> to<00:17:42.520> explain 00:17:43.110 --> 00:17:43.120 align:start position:0% article in Nature to attempt to explain 00:17:43.120 --> 00:17:45.230 align:start position:0% article in Nature to attempt to explain this<00:17:43.280> discrepancy. 00:17:45.230 --> 00:17:45.240 align:start position:0% this discrepancy. 00:17:45.240 --> 00:17:48.190 align:start position:0% this discrepancy. The<00:17:45.360> team<00:17:45.880> was<00:17:46.080> made<00:17:46.360> up<00:17:46.600> of<00:17:46.720> Yehuda<00:17:47.200> Hoffman, 00:17:48.190 --> 00:17:48.200 align:start position:0% The team was made up of Yehuda Hoffman, 00:17:48.200 --> 00:17:50.270 align:start position:0% The team was made up of Yehuda Hoffman, Daniel<00:17:48.840> Pomarede, 00:17:50.270 --> 00:17:50.280 align:start position:0% Daniel Pomarede, 00:17:50.280 --> 00:17:53.547 align:start position:0% Daniel Pomarede, R.<00:17:50.640> Brent<00:17:51.120> Tully,<00:17:51.960> and<00:17:52.160> Helene<00:17:53.000> M.<00:17:53.360> Courtois. 00:17:53.547 --> 00:17:53.557 align:start position:0% R. Brent Tully, and Helene M. Courtois. 00:17:53.557 --> 00:17:54.670 align:start position:0% R. Brent Tully, and Helene M. Courtois. [music] 00:17:54.670 --> 00:17:54.680 align:start position:0% [music] 00:17:54.680 --> 00:17:57.030 align:start position:0% [music] Together,<00:17:55.040> they<00:17:55.200> created<00:17:55.760> a<00:17:55.880> new<00:17:56.240> kind<00:17:56.600> of<00:17:56.720> map 00:17:57.030 --> 00:17:57.040 align:start position:0% Together, they created a new kind of map 00:17:57.040 --> 00:17:58.787 align:start position:0% Together, they created a new kind of map of<00:17:57.160> the<00:17:57.280> local<00:17:57.600> universe<00:17:58.040> around<00:17:58.400> us. 00:17:58.787 --> 00:17:58.797 align:start position:0% of the local universe around us. 00:17:58.797 --> 00:17:59.150 align:start position:0% of the local universe around us. >> [music] 00:17:59.150 --> 00:17:59.160 align:start position:0% >> [music] 00:17:59.160 --> 00:18:01.430 align:start position:0% >> [music] >> This<00:17:59.320> time,<00:18:00.000> instead<00:18:00.240> of<00:18:00.360> simply<00:18:00.800> noting 00:18:01.430 --> 00:18:01.440 align:start position:0% >> This time, instead of simply noting 00:18:01.440 --> 00:18:03.750 align:start position:0% >> This time, instead of simply noting galaxies'<00:18:02.000> positions,<00:18:03.040> they<00:18:03.200> highlighted 00:18:03.750 --> 00:18:03.760 align:start position:0% galaxies' positions, they highlighted 00:18:03.760 --> 00:18:06.270 align:start position:0% galaxies' positions, they highlighted their<00:18:04.080> motions<00:18:04.800> instead. 00:18:06.270 --> 00:18:06.280 align:start position:0% their motions instead. 00:18:06.280 --> 00:18:08.270 align:start position:0% their motions instead. This<00:18:06.560> allowed<00:18:06.880> them<00:18:07.080> to<00:18:07.160> create<00:18:07.480> a<00:18:07.560> map<00:18:08.080> of 00:18:08.270 --> 00:18:08.280 align:start position:0% This allowed them to create a map of 00:18:08.280 --> 00:18:10.910 align:start position:0% This allowed them to create a map of flow<00:18:08.560> lines,<00:18:09.400> which,<00:18:10.040> after<00:18:10.320> mathematical 00:18:10.910 --> 00:18:10.920 align:start position:0% flow lines, which, after mathematical 00:18:10.920 --> 00:18:12.670 align:start position:0% flow lines, which, after mathematical analysis,<00:18:11.960> allowed<00:18:12.280> them<00:18:12.400> to<00:18:12.520> make 00:18:12.670 --> 00:18:12.680 align:start position:0% analysis, allowed them to make 00:18:12.680 --> 00:18:14.630 align:start position:0% analysis, allowed them to make assumptions<00:18:13.280> about<00:18:13.600> the<00:18:13.680> locations<00:18:14.480> of 00:18:14.630 --> 00:18:14.640 align:start position:0% assumptions about the locations of 00:18:14.640 --> 00:18:17.830 align:start position:0% assumptions about the locations of masses<00:18:15.240> in<00:18:15.480> our<00:18:15.680> nearby<00:18:16.120> superclusters. 00:18:17.830 --> 00:18:17.840 align:start position:0% masses in our nearby superclusters. 00:18:17.840 --> 00:18:20.270 align:start position:0% masses in our nearby superclusters. Their<00:18:17.960> results<00:18:18.680> were<00:18:18.800> surprising. 00:18:20.270 --> 00:18:20.280 align:start position:0% Their results were surprising. 00:18:20.280 --> 00:18:22.350 align:start position:0% Their results were surprising. A<00:18:20.360> lot<00:18:20.640> of<00:18:20.760> our<00:18:20.920> local<00:18:21.280> mass<00:18:21.800> is<00:18:22.000> moving 00:18:22.350 --> 00:18:22.360 align:start position:0% A lot of our local mass is moving 00:18:22.360 --> 00:18:24.350 align:start position:0% A lot of our local mass is moving towards<00:18:22.760> the<00:18:22.880> Shapley<00:18:23.240> Supercluster,<00:18:24.160> which 00:18:24.350 --> 00:18:24.360 align:start position:0% towards the Shapley Supercluster, which 00:18:24.360 --> 00:18:26.230 align:start position:0% towards the Shapley Supercluster, which is<00:18:24.560> what<00:18:24.760> you<00:18:24.840> would<00:18:24.960> expect. 00:18:26.230 --> 00:18:26.240 align:start position:0% is what you would expect. 00:18:26.240 --> 00:18:28.510 align:start position:0% is what you would expect. But,<00:18:26.280> they<00:18:26.480> also<00:18:26.880> found<00:18:27.240> a<00:18:27.360> lot<00:18:27.840> of<00:18:28.000> mass<00:18:28.320> is 00:18:28.510 --> 00:18:28.520 align:start position:0% But, they also found a lot of mass is 00:18:28.520 --> 00:18:32.030 align:start position:0% But, they also found a lot of mass is moving<00:18:29.040> away<00:18:30.080> from<00:18:30.240> another<00:18:30.720> specific<00:18:31.600> region 00:18:32.030 --> 00:18:32.040 align:start position:0% moving away from another specific region 00:18:32.040 --> 00:18:33.550 align:start position:0% moving away from another specific region in<00:18:32.200> space. 00:18:33.550 --> 00:18:33.560 align:start position:0% in space. 00:18:33.560 --> 00:18:35.790 align:start position:0% in space. They<00:18:33.640> call<00:18:33.920> this<00:18:34.160> mystery<00:18:34.600> patch<00:18:34.920> of<00:18:35.000> space 00:18:35.790 --> 00:18:35.800 align:start position:0% They call this mystery patch of space 00:18:35.800 --> 00:18:38.510 align:start position:0% They call this mystery patch of space the<00:18:35.960> Dipole<00:18:36.640> Repeller. 00:18:38.510 --> 00:18:38.520 align:start position:0% the Dipole Repeller. 00:18:38.520 --> 00:18:40.430 align:start position:0% the Dipole Repeller. Together,<00:18:39.120> the<00:18:39.240> Dipole<00:18:39.680> Repeller<00:18:40.200> and<00:18:40.360> the 00:18:40.430 --> 00:18:40.440 align:start position:0% Together, the Dipole Repeller and the 00:18:40.440 --> 00:18:43.110 align:start position:0% Together, the Dipole Repeller and the Shapley<00:18:40.800> Attractor<00:18:41.640> both<00:18:42.000> contribute<00:18:42.720> about 00:18:43.110 --> 00:18:43.120 align:start position:0% Shapley Attractor both contribute about 00:18:43.120 --> 00:18:46.750 align:start position:0% Shapley Attractor both contribute about 50%<00:18:44.200> to<00:18:44.440> our<00:18:44.680> motion,<00:18:45.760> working<00:18:46.120> together<00:18:46.600> in 00:18:46.750 --> 00:18:46.760 align:start position:0% 50% to our motion, working together in 00:18:46.760 --> 00:18:49.550 align:start position:0% 50% to our motion, working together in tandem,<00:18:47.560> hence<00:18:47.800> the<00:18:47.880> name<00:18:48.200> dipole. 00:18:49.550 --> 00:18:49.560 align:start position:0% tandem, hence the name dipole. 00:18:49.560 --> 00:18:52.110 align:start position:0% tandem, hence the name dipole. But,<00:18:50.040> how? 00:18:52.110 --> 00:18:52.120 align:start position:0% But, how? 00:18:52.120 --> 00:18:53.808 align:start position:0% But, how? Gravity<00:18:52.600> is<00:18:52.760> a<00:18:52.840> force<00:18:53.200> that, 00:18:53.808 --> 00:18:53.818 align:start position:0% Gravity is a force that, 00:18:53.818 --> 00:18:53.870 align:start position:0% Gravity is a force that, >> [music] 00:18:53.870 --> 00:18:53.880 align:start position:0% >> [music] 00:18:53.880 --> 00:18:57.790 align:start position:0% >> [music] >> so<00:18:54.120> far<00:18:54.400> as<00:18:54.560> we<00:18:54.720> have<00:18:54.880> observed,<00:18:56.000> only<00:18:56.360> pulls. 00:18:57.790 --> 00:18:57.800 align:start position:0% >> so far as we have observed, only pulls. 00:18:57.800 --> 00:18:59.470 align:start position:0% >> so far as we have observed, only pulls. What<00:18:58.040> lies<00:18:58.600> in<00:18:58.760> this<00:18:59.000> region<00:18:59.058> [music]<00:18:59.360> of 00:18:59.470 --> 00:18:59.480 align:start position:0% What lies in this region [music] of 00:18:59.480 --> 00:19:02.910 align:start position:0% What lies in this region [music] of space<00:19:00.000> that<00:19:00.200> allows<00:19:00.680> a<00:19:00.880> push<00:19:01.440> to<00:19:01.600> happen? 00:19:02.910 --> 00:19:02.920 align:start position:0% space that allows a push to happen? 00:19:02.920 --> 00:19:04.710 align:start position:0% space that allows a push to happen? Could<00:19:03.080> it<00:19:03.200> be<00:19:03.360> a<00:19:03.440> strange<00:19:04.000> collection<00:19:04.520> of 00:19:04.710 --> 00:19:04.720 align:start position:0% Could it be a strange collection of 00:19:04.720 --> 00:19:07.430 align:start position:0% Could it be a strange collection of white<00:19:05.000> holes,<00:19:06.040> the<00:19:06.160> theoretical<00:19:06.920> opposite<00:19:07.320> of 00:19:07.430 --> 00:19:07.440 align:start position:0% white holes, the theoretical opposite of 00:19:07.440 --> 00:19:08.950 align:start position:0% white holes, the theoretical opposite of black<00:19:07.720> holes<00:19:08.040> that<00:19:08.120> we've<00:19:08.280> talked<00:19:08.600> about<00:19:08.840> in 00:19:08.950 --> 00:19:08.960 align:start position:0% black holes that we've talked about in 00:19:08.960 --> 00:19:10.590 align:start position:0% black holes that we've talked about in videos<00:19:09.320> before? 00:19:10.590 --> 00:19:10.600 align:start position:0% videos before? 00:19:10.600 --> 00:19:12.310 align:start position:0% videos before? Or<00:19:10.680> perhaps<00:19:11.400> some<00:19:11.503> [music]<00:19:11.680> sort<00:19:12.120> of 00:19:12.310 --> 00:19:12.320 align:start position:0% Or perhaps some [music] sort of 00:19:12.320 --> 00:19:14.270 align:start position:0% Or perhaps some [music] sort of anti-gravity. 00:19:14.270 --> 00:19:14.280 align:start position:0% anti-gravity. 00:19:14.280 --> 00:19:15.630 align:start position:0% anti-gravity. Not<00:19:14.520> quite. 00:19:15.630 --> 00:19:15.640 align:start position:0% Not quite. 00:19:15.640 --> 00:19:17.350 align:start position:0% Not quite. The<00:19:15.800> answer<00:19:16.200> is 00:19:17.350 --> 00:19:17.360 align:start position:0% The answer is 00:19:17.360 --> 00:19:19.030 align:start position:0% The answer is nothing. 00:19:19.030 --> 00:19:19.040 align:start position:0% nothing. 00:19:19.040 --> 00:19:21.830 align:start position:0% nothing. The<00:19:19.080> Dipole<00:19:19.520> Repeller<00:19:20.040> is<00:19:20.200> a<00:19:20.280> void,<00:19:21.200> a<00:19:21.320> bubble 00:19:21.830 --> 00:19:21.840 align:start position:0% The Dipole Repeller is a void, a bubble 00:19:21.840 --> 00:19:24.550 align:start position:0% The Dipole Repeller is a void, a bubble about<00:19:22.240> 100<00:19:22.920> million<00:19:23.360> light-years<00:19:23.720> across 00:19:24.550 --> 00:19:24.560 align:start position:0% about 100 million light-years across 00:19:24.560 --> 00:19:27.510 align:start position:0% about 100 million light-years across that<00:19:24.720> does<00:19:24.920> not<00:19:25.280> contain<00:19:25.760> many,<00:19:26.320> if<00:19:26.720> any, 00:19:27.510 --> 00:19:27.520 align:start position:0% that does not contain many, if any, 00:19:27.520 --> 00:19:29.150 align:start position:0% that does not contain many, if any, major<00:19:27.880> galaxies. 00:19:29.150 --> 00:19:29.160 align:start position:0% major galaxies. 00:19:29.160 --> 00:19:30.830 align:start position:0% major galaxies. It's<00:19:29.440> one<00:19:29.640> of<00:19:29.720> the<00:19:29.800> bubbles<00:19:30.240> that<00:19:30.400> exist 00:19:30.830 --> 00:19:30.840 align:start position:0% It's one of the bubbles that exist 00:19:30.840 --> 00:19:32.710 align:start position:0% It's one of the bubbles that exist between<00:19:31.280> the<00:19:31.400> filaments<00:19:31.880> of<00:19:32.000> the<00:19:32.120> universe's 00:19:32.710 --> 00:19:32.720 align:start position:0% between the filaments of the universe's 00:19:32.720 --> 00:19:34.070 align:start position:0% between the filaments of the universe's structures. 00:19:34.070 --> 00:19:34.080 align:start position:0% structures. 00:19:34.080 --> 00:19:36.950 align:start position:0% structures. But,<00:19:34.360> interestingly,<00:19:35.600> our<00:19:35.880> galaxy's<00:19:36.520> current 00:19:36.950 --> 00:19:36.960 align:start position:0% But, interestingly, our galaxy's current 00:19:36.960 --> 00:19:40.230 align:start position:0% But, interestingly, our galaxy's current motion<00:19:37.680> lines<00:19:38.080> up<00:19:38.360> much<00:19:38.840> more<00:19:39.080> satisfyingly 00:19:40.230 --> 00:19:40.240 align:start position:0% motion lines up much more satisfyingly 00:19:40.240 --> 00:19:42.590 align:start position:0% motion lines up much more satisfyingly with<00:19:40.400> the<00:19:40.560> push<00:19:41.080> from<00:19:41.280> this<00:19:41.520> region<00:19:42.360> than<00:19:42.480> it 00:19:42.590 --> 00:19:42.600 align:start position:0% with the push from this region than it 00:19:42.600 --> 00:19:44.750 align:start position:0% with the push from this region than it does<00:19:43.000> from<00:19:43.200> the<00:19:43.320> pull<00:19:44.080> of<00:19:44.240> the<00:19:44.360> Shapley 00:19:44.750 --> 00:19:44.760 align:start position:0% does from the pull of the Shapley 00:19:44.760 --> 00:19:46.150 align:start position:0% does from the pull of the Shapley Attractor, 00:19:46.150 --> 00:19:46.160 align:start position:0% Attractor, 00:19:46.160 --> 00:19:48.350 align:start position:0% Attractor, which<00:19:46.360> is<00:19:46.640> a<00:19:46.760> compelling<00:19:47.480> argument<00:19:48.040> in<00:19:48.160> this 00:19:48.350 --> 00:19:48.360 align:start position:0% which is a compelling argument in this 00:19:48.360 --> 00:19:50.390 align:start position:0% which is a compelling argument in this theory's<00:19:48.880> favor. 00:19:50.390 --> 00:19:50.400 align:start position:0% theory's favor. 00:19:50.400 --> 00:19:54.270 align:start position:0% theory's favor. So,<00:19:51.000> how<00:19:51.560> does<00:19:51.840> nothing<00:19:52.520> push? 00:19:54.270 --> 00:19:54.280 align:start position:0% So, how does nothing push? 00:19:54.280 --> 00:19:56.230 align:start position:0% So, how does nothing push? The<00:19:54.400> answer<00:19:54.760> is<00:19:55.000> actually<00:19:55.480> that<00:19:55.640> this<00:19:55.920> could 00:19:56.230 --> 00:19:56.240 align:start position:0% The answer is actually that this could 00:19:56.240 --> 00:19:58.950 align:start position:0% The answer is actually that this could be<00:19:56.520> a<00:19:56.640> pseudo<00:19:57.120> force<00:19:57.880> more<00:19:58.200> than<00:19:58.360> it<00:19:58.480> is<00:19:58.640> a<00:19:58.720> real 00:19:58.950 --> 00:19:58.960 align:start position:0% be a pseudo force more than it is a real 00:19:58.960 --> 00:19:59.950 align:start position:0% be a pseudo force more than it is a real one. 00:19:59.950 --> 00:19:59.960 align:start position:0% one. 00:19:59.960 --> 00:20:01.670 align:start position:0% one. Imagine<00:20:00.560> a<00:20:00.640> universe<00:20:01.240> where<00:20:01.440> all<00:20:01.600> the 00:20:01.670 --> 00:20:01.680 align:start position:0% Imagine a universe where all the 00:20:01.680 --> 00:20:03.950 align:start position:0% Imagine a universe where all the galaxies<00:20:02.280> were<00:20:02.400> spaced<00:20:02.840> equally. 00:20:03.950 --> 00:20:03.960 align:start position:0% galaxies were spaced equally. 00:20:03.960 --> 00:20:05.830 align:start position:0% galaxies were spaced equally. While<00:20:04.080> the<00:20:04.200> gravity<00:20:04.600> of<00:20:04.680> galaxies<00:20:05.280> above 00:20:05.830 --> 00:20:05.840 align:start position:0% While the gravity of galaxies above 00:20:05.840 --> 00:20:08.030 align:start position:0% While the gravity of galaxies above would<00:20:06.040> pull<00:20:06.280> you,<00:20:06.880> the<00:20:06.960> gravity<00:20:07.320> of<00:20:07.440> galaxies 00:20:08.030 --> 00:20:08.040 align:start position:0% would pull you, the gravity of galaxies 00:20:08.040 --> 00:20:10.790 align:start position:0% would pull you, the gravity of galaxies below<00:20:08.440> you<00:20:08.840> would<00:20:08.960> do<00:20:09.120> the<00:20:09.240> same.<00:20:10.200> So<00:20:10.400> would 00:20:10.790 --> 00:20:10.800 align:start position:0% below you would do the same. So would 00:20:10.800 --> 00:20:12.790 align:start position:0% below you would do the same. So would the<00:20:10.920> pull<00:20:11.200> of<00:20:11.320> galaxies<00:20:11.800> to<00:20:11.920> your<00:20:12.040> left<00:20:12.560> and<00:20:12.680> to 00:20:12.790 --> 00:20:12.800 align:start position:0% the pull of galaxies to your left and to 00:20:12.800 --> 00:20:15.030 align:start position:0% the pull of galaxies to your left and to your<00:20:12.920> right.<00:20:13.920> In<00:20:13.960> this<00:20:14.200> way,<00:20:14.480> the<00:20:14.600> varying 00:20:15.030 --> 00:20:15.040 align:start position:0% your right. In this way, the varying 00:20:15.040 --> 00:20:16.790 align:start position:0% your right. In this way, the varying forces<00:20:15.520> of<00:20:15.640> all<00:20:15.800> these<00:20:16.000> gravities<00:20:16.560> would 00:20:16.790 --> 00:20:16.800 align:start position:0% forces of all these gravities would 00:20:16.800 --> 00:20:19.270 align:start position:0% forces of all these gravities would balance<00:20:17.200> each<00:20:17.400> other,<00:20:17.960> leaving<00:20:18.320> you<00:20:18.800> to<00:20:18.920> not 00:20:19.270 --> 00:20:19.280 align:start position:0% balance each other, leaving you to not 00:20:19.280 --> 00:20:21.710 align:start position:0% balance each other, leaving you to not really<00:20:19.480> travel<00:20:19.880> in<00:20:20.040> any<00:20:20.200> direction.<00:20:21.240> You'd<00:20:21.440> be 00:20:21.710 --> 00:20:21.720 align:start position:0% really travel in any direction. You'd be 00:20:21.720 --> 00:20:23.870 align:start position:0% really travel in any direction. You'd be in<00:20:21.840> a<00:20:21.920> perfect<00:20:22.480> equilibrium. 00:20:23.870 --> 00:20:23.880 align:start position:0% in a perfect equilibrium. 00:20:23.880 --> 00:20:25.630 align:start position:0% in a perfect equilibrium. But,<00:20:24.000> what<00:20:24.160> would<00:20:24.360> happen<00:20:24.720> if<00:20:24.880> we<00:20:25.040> removed<00:20:25.560> the 00:20:25.630 --> 00:20:25.640 align:start position:0% But, what would happen if we removed the 00:20:25.640 --> 00:20:28.350 align:start position:0% But, what would happen if we removed the galaxies<00:20:26.240> from<00:20:26.560> one<00:20:26.720> of<00:20:26.840> these<00:20:27.040> directions? 00:20:28.350 --> 00:20:28.360 align:start position:0% galaxies from one of these directions? 00:20:28.360 --> 00:20:30.070 align:start position:0% galaxies from one of these directions? What<00:20:28.640> would<00:20:28.794> [music]<00:20:28.840> happen<00:20:29.280> if<00:20:29.440> we<00:20:29.600> added<00:20:30.040> a 00:20:30.070 --> 00:20:30.080 align:start position:0% What would [music] happen if we added a 00:20:30.080 --> 00:20:31.390 align:start position:0% What would [music] happen if we added a void? 00:20:31.390 --> 00:20:31.400 align:start position:0% void? 00:20:31.400 --> 00:20:33.950 align:start position:0% void? Well,<00:20:32.040> then<00:20:32.280> the<00:20:32.400> scales<00:20:32.760> would<00:20:32.920> tip. 00:20:33.950 --> 00:20:33.960 align:start position:0% Well, then the scales would tip. 00:20:33.960 --> 00:20:35.550 align:start position:0% Well, then the scales would tip. There<00:20:34.080> would<00:20:34.240> be<00:20:34.480> one<00:20:34.680> direction<00:20:35.200> that<00:20:35.360> no 00:20:35.550 --> 00:20:35.560 align:start position:0% There would be one direction that no 00:20:35.560 --> 00:20:37.470 align:start position:0% There would be one direction that no longer<00:20:35.960> pulls<00:20:35.999> [music]<00:20:36.320> you,<00:20:36.880> leaving<00:20:37.280> the 00:20:37.470 --> 00:20:37.480 align:start position:0% longer pulls [music] you, leaving the 00:20:37.480 --> 00:20:39.590 align:start position:0% longer pulls [music] you, leaving the opposite<00:20:37.920> direction's<00:20:38.480> pull<00:20:38.760> to<00:20:38.920> act<00:20:39.200> on<00:20:39.360> you 00:20:39.590 --> 00:20:39.600 align:start position:0% opposite direction's pull to act on you 00:20:39.600 --> 00:20:42.350 align:start position:0% opposite direction's pull to act on you unimpeded.<00:20:41.080> As<00:20:41.240> a<00:20:41.320> result,<00:20:41.800> you<00:20:41.920> would<00:20:42.120> move 00:20:42.350 --> 00:20:42.360 align:start position:0% unimpeded. As a result, you would move 00:20:42.360 --> 00:20:45.110 align:start position:0% unimpeded. As a result, you would move away<00:20:42.680> from<00:20:42.840> the<00:20:42.960> void<00:20:43.680> as<00:20:43.859> [music]<00:20:44.120> if<00:20:44.760> it<00:20:44.960> were 00:20:45.110 --> 00:20:45.120 align:start position:0% away from the void as [music] if it were 00:20:45.120 --> 00:20:46.630 align:start position:0% away from the void as [music] if it were pushing<00:20:45.600> you. 00:20:46.630 --> 00:20:46.640 align:start position:0% pushing you. 00:20:46.640 --> 00:20:48.910 align:start position:0% pushing you. Everything<00:20:47.040> near<00:20:47.320> a<00:20:47.360> void<00:20:48.040> will<00:20:48.240> thus<00:20:48.680> move 00:20:48.910 --> 00:20:48.920 align:start position:0% Everything near a void will thus move 00:20:48.920 --> 00:20:51.870 align:start position:0% Everything near a void will thus move away<00:20:49.160> from<00:20:49.440> it,<00:20:49.960> making<00:20:50.280> it<00:20:50.520> seem<00:20:51.240> to<00:20:51.400> have<00:20:51.760> a 00:20:51.870 --> 00:20:51.880 align:start position:0% away from it, making it seem to have a 00:20:51.880 --> 00:20:54.329 align:start position:0% away from it, making it seem to have a repelling<00:20:52.640> gravitational<00:20:53.320> force. 00:20:54.329 --> 00:20:54.339 align:start position:0% repelling gravitational force. 00:20:54.339 --> 00:20:54.550 align:start position:0% repelling gravitational force. >> [music] 00:20:54.550 --> 00:20:54.560 align:start position:0% >> [music] 00:20:54.560 --> 00:20:58.310 align:start position:0% >> [music] >> It<00:20:54.680> is<00:20:54.800> something<00:20:55.360> of<00:20:55.520> an<00:20:55.640> optical<00:20:56.040> illusion. 00:20:58.310 --> 00:20:58.320 align:start position:0% >> It is something of an optical illusion. 00:20:58.320 --> 00:21:00.230 align:start position:0% >> It is something of an optical illusion. There<00:20:58.480> is<00:20:58.920> another<00:20:58.940> [music]<00:20:59.280> explanation<00:21:00.040> for 00:21:00.230 --> 00:21:00.240 align:start position:0% There is another [music] explanation for 00:21:00.240 --> 00:21:03.110 align:start position:0% There is another [music] explanation for why<00:21:00.560> a<00:21:00.680> void<00:21:01.160> space<00:21:01.680> might<00:21:01.960> push<00:21:02.240> you,<00:21:02.920> which 00:21:03.110 --> 00:21:03.120 align:start position:0% why a void space might push you, which 00:21:03.120 --> 00:21:04.430 align:start position:0% why a void space might push you, which might<00:21:03.360> work<00:21:03.509> [music]<00:21:03.600> in<00:21:03.760> tandem<00:21:04.240> with<00:21:04.360> the 00:21:04.430 --> 00:21:04.440 align:start position:0% might work [music] in tandem with the 00:21:04.440 --> 00:21:06.230 align:start position:0% might work [music] in tandem with the pseudo<00:21:04.840> force. 00:21:06.230 --> 00:21:06.240 align:start position:0% pseudo force. 00:21:06.240 --> 00:21:08.350 align:start position:0% pseudo force. The<00:21:06.280> universe<00:21:06.840> is<00:21:06.960> expanding,<00:21:08.120> and<00:21:08.240> that 00:21:08.350 --> 00:21:08.360 align:start position:0% The universe is expanding, and that 00:21:08.360 --> 00:21:11.230 align:start position:0% The universe is expanding, and that expansion<00:21:09.000> shows<00:21:09.360> no<00:21:09.520> sign<00:21:09.960> of<00:21:10.080> slowing<00:21:10.400> down. 00:21:11.230 --> 00:21:11.240 align:start position:0% expansion shows no sign of slowing down. 00:21:11.240 --> 00:21:14.190 align:start position:0% expansion shows no sign of slowing down. In<00:21:11.360> fact,<00:21:12.040> it<00:21:12.200> seems<00:21:12.520> to<00:21:12.600> be<00:21:12.720> speeding<00:21:13.200> up. 00:21:14.190 --> 00:21:14.200 align:start position:0% In fact, it seems to be speeding up. 00:21:14.200 --> 00:21:16.110 align:start position:0% In fact, it seems to be speeding up. However,<00:21:14.520> this<00:21:14.680> expansion<00:21:15.240> is<00:21:15.400> counteracted 00:21:16.110 --> 00:21:16.120 align:start position:0% However, this expansion is counteracted 00:21:16.120 --> 00:21:18.830 align:start position:0% However, this expansion is counteracted by<00:21:16.280> gravity,<00:21:17.400> and<00:21:17.520> in<00:21:17.680> areas<00:21:18.200> where<00:21:18.400> there<00:21:18.680> is 00:21:18.830 --> 00:21:18.840 align:start position:0% by gravity, and in areas where there is 00:21:18.840 --> 00:21:21.750 align:start position:0% by gravity, and in areas where there is more<00:21:19.200> gravity,<00:21:20.240> less<00:21:20.640> expansion<00:21:21.320> seems<00:21:21.680> to 00:21:21.750 --> 00:21:21.760 align:start position:0% more gravity, less expansion seems to 00:21:21.760 --> 00:21:23.070 align:start position:0% more gravity, less expansion seems to take<00:21:22.000> place. 00:21:23.070 --> 00:21:23.080 align:start position:0% take place. 00:21:23.080 --> 00:21:24.870 align:start position:0% take place. Stars<00:21:23.440> aren't<00:21:23.680> just<00:21:24.000> being<00:21:24.240> pushed<00:21:24.520> away<00:21:24.720> from 00:21:24.870 --> 00:21:24.880 align:start position:0% Stars aren't just being pushed away from 00:21:24.880 --> 00:21:26.870 align:start position:0% Stars aren't just being pushed away from each<00:21:25.080> other,<00:21:25.760> they're<00:21:25.960> also<00:21:26.280> being<00:21:26.520> pulled 00:21:26.870 --> 00:21:26.880 align:start position:0% each other, they're also being pulled 00:21:26.880 --> 00:21:28.150 align:start position:0% each other, they're also being pulled together. 00:21:28.150 --> 00:21:28.160 align:start position:0% together. 00:21:28.160 --> 00:21:30.670 align:start position:0% together. Conversely,<00:21:28.960> in<00:21:29.080> a<00:21:29.160> void,<00:21:29.720> there<00:21:29.880> is<00:21:30.000> nothing 00:21:30.670 --> 00:21:30.680 align:start position:0% Conversely, in a void, there is nothing 00:21:30.680 --> 00:21:32.319 align:start position:0% Conversely, in a void, there is nothing to<00:21:30.800> contain<00:21:31.280> this<00:21:31.560> rampant<00:21:32.160> expansion. 00:21:32.319 --> 00:21:32.329 align:start position:0% to contain this rampant expansion. 00:21:32.329 --> 00:21:33.670 align:start position:0% to contain this rampant expansion. [music] 00:21:33.670 --> 00:21:33.680 align:start position:0% [music] 00:21:33.680 --> 00:21:36.390 align:start position:0% [music] As<00:21:33.800> a<00:21:33.840> result,<00:21:34.720> void<00:21:35.040> spaces<00:21:35.640> literally<00:21:36.200> will 00:21:36.390 --> 00:21:36.400 align:start position:0% As a result, void spaces literally will 00:21:36.400 --> 00:21:38.830 align:start position:0% As a result, void spaces literally will swell<00:21:37.400> compared<00:21:37.880> to<00:21:37.960> their<00:21:38.160> supercluster 00:21:38.830 --> 00:21:38.840 align:start position:0% swell compared to their supercluster 00:21:38.840 --> 00:21:40.310 align:start position:0% swell compared to their supercluster counterparts. 00:21:40.310 --> 00:21:40.320 align:start position:0% counterparts. 00:21:40.320 --> 00:21:42.350 align:start position:0% counterparts. It<00:21:40.440> might<00:21:40.680> be<00:21:40.800> done<00:21:41.120> by<00:21:41.400> warping<00:21:41.880> the<00:21:41.960> fabric 00:21:42.350 --> 00:21:42.360 align:start position:0% It might be done by warping the fabric 00:21:42.360 --> 00:21:45.230 align:start position:0% It might be done by warping the fabric of<00:21:42.480> reality,<00:21:43.520> but<00:21:43.760> this<00:21:44.120> also<00:21:44.600> achieves<00:21:45.160> a 00:21:45.230 --> 00:21:45.240 align:start position:0% of reality, but this also achieves a 00:21:45.240 --> 00:21:48.710 align:start position:0% of reality, but this also achieves a sort<00:21:45.560> of<00:21:45.760> push. 00:21:48.710 --> 00:21:48.720 align:start position:0% 00:21:48.720 --> 00:21:52.110 align:start position:0% Since<00:21:49.320> 2017,<00:21:50.680> not<00:21:50.920> much<00:21:51.200> more<00:21:51.600> has<00:21:51.800> come<00:21:52.000> to 00:21:52.110 --> 00:21:52.120 align:start position:0% Since 2017, not much more has come to 00:21:52.120 --> 00:21:53.510 align:start position:0% Since 2017, not much more has come to light<00:21:52.440> about<00:21:52.720> the<00:21:52.800> existence<00:21:53.290> [music]<00:21:53.320> of<00:21:53.440> the 00:21:53.510 --> 00:21:53.520 align:start position:0% light about the existence [music] of the 00:21:53.520 --> 00:21:56.270 align:start position:0% light about the existence [music] of the Dipole<00:21:54.040> Repeller.<00:21:55.120> As<00:21:55.280> this<00:21:55.520> is<00:21:55.640> still<00:21:56.160> an 00:21:56.270 --> 00:21:56.280 align:start position:0% Dipole Repeller. As this is still an 00:21:56.280 --> 00:21:58.670 align:start position:0% Dipole Repeller. As this is still an expanding<00:21:57.000> field<00:21:57.360> of<00:21:57.480> research,<00:21:58.400> there's 00:21:58.670 --> 00:21:58.680 align:start position:0% expanding field of research, there's 00:21:58.680 --> 00:22:00.870 align:start position:0% expanding field of research, there's some<00:21:58.960> debate<00:21:59.440> about<00:21:59.720> whether<00:22:00.080> it's<00:22:00.400> really 00:22:00.870 --> 00:22:00.880 align:start position:0% some debate about whether it's really 00:22:00.880 --> 00:22:03.590 align:start position:0% some debate about whether it's really there<00:22:01.720> or<00:22:02.000> how<00:22:02.280> influential<00:22:02.920> it<00:22:03.000> might<00:22:03.240> be<00:22:03.440> on 00:22:03.590 --> 00:22:03.600 align:start position:0% there or how influential it might be on 00:22:03.600 --> 00:22:05.910 align:start position:0% there or how influential it might be on our<00:22:03.800> galaxy's<00:22:04.320> current<00:22:04.640> motion. 00:22:05.910 --> 00:22:05.920 align:start position:0% our galaxy's current motion. 00:22:05.920 --> 00:22:08.150 align:start position:0% our galaxy's current motion. It<00:22:06.000> is<00:22:06.240> difficult<00:22:06.720> to<00:22:06.800> observe<00:22:07.760> due<00:22:07.960> to<00:22:08.080> the 00:22:08.150 --> 00:22:08.160 align:start position:0% It is difficult to observe due to the 00:22:08.160 --> 00:22:10.350 align:start position:0% It is difficult to observe due to the Milky<00:22:08.355> [music]<00:22:08.480> Way's<00:22:08.800> obscuring<00:22:09.320> effect, 00:22:10.350 --> 00:22:10.360 align:start position:0% Milky [music] Way's obscuring effect, 00:22:10.360 --> 00:22:12.510 align:start position:0% Milky [music] Way's obscuring effect, and<00:22:10.480> there<00:22:10.600> is<00:22:10.760> always<00:22:11.280> a<00:22:11.360> challenge<00:22:11.920> inherent 00:22:12.510 --> 00:22:12.520 align:start position:0% and there is always a challenge inherent 00:22:12.520 --> 00:22:14.350 align:start position:0% and there is always a challenge inherent in<00:22:12.640> trying<00:22:12.940> [music]<00:22:12.960> to<00:22:13.080> spot<00:22:13.480> the<00:22:13.720> absence<00:22:14.240> of 00:22:14.350 --> 00:22:14.360 align:start position:0% in trying [music] to spot the absence of 00:22:14.360 --> 00:22:17.270 align:start position:0% in trying [music] to spot the absence of a<00:22:14.400> thing<00:22:15.040> rather<00:22:15.360> than<00:22:15.600> its<00:22:15.760> presence. 00:22:17.270 --> 00:22:17.280 align:start position:0% a thing rather than its presence. 00:22:17.280 --> 00:22:19.110 align:start position:0% a thing rather than its presence. However,<00:22:18.000> Tully<00:22:18.560> and<00:22:18.680> his<00:22:18.840> fellow 00:22:19.110 --> 00:22:19.120 align:start position:0% However, Tully and his fellow 00:22:19.120 --> 00:22:21.590 align:start position:0% However, Tully and his fellow researchers<00:22:19.760> hope<00:22:20.400> that<00:22:20.640> with<00:22:20.800> the<00:22:21.040> aid<00:22:21.400> of 00:22:21.590 --> 00:22:21.600 align:start position:0% researchers hope that with the aid of 00:22:21.600 --> 00:22:24.190 align:start position:0% researchers hope that with the aid of future<00:22:22.160> ultra-sensitive<00:22:23.080> surveys<00:22:24.040> in 00:22:24.190 --> 00:22:24.200 align:start position:0% future ultra-sensitive surveys in 00:22:24.200 --> 00:22:26.550 align:start position:0% future ultra-sensitive surveys in multiple<00:22:24.600> spectrums<00:22:25.160> of<00:22:25.320> light,<00:22:26.200> it<00:22:26.320> will<00:22:26.440> be 00:22:26.550 --> 00:22:26.560 align:start position:0% multiple spectrums of light, it will be 00:22:26.560 --> 00:22:28.270 align:start position:0% multiple spectrums of light, it will be possible<00:22:27.200> to<00:22:27.320> map<00:22:27.640> out<00:22:27.920> the<00:22:28.005> [music]<00:22:28.040> few 00:22:28.270 --> 00:22:28.280 align:start position:0% possible to map out the [music] few 00:22:28.280 --> 00:22:31.150 align:start position:0% possible to map out the [music] few galaxies<00:22:28.960> that<00:22:29.240> lie<00:22:29.600> in<00:22:29.760> this<00:22:29.960> void<00:22:30.840> and 00:22:31.150 --> 00:22:31.160 align:start position:0% galaxies that lie in this void and 00:22:31.160 --> 00:22:33.150 align:start position:0% galaxies that lie in this void and generally<00:22:31.640> confirm<00:22:32.160> its<00:22:32.280> existence<00:22:32.960> in<00:22:33.080> the 00:22:33.150 --> 00:22:33.160 align:start position:0% generally confirm its existence in the 00:22:33.160 --> 00:22:37.430 align:start position:0% generally confirm its existence in the region<00:22:33.520> they<00:22:33.640> hypothesize. 00:22:37.430 --> 00:22:37.440 align:start position:0% 00:22:37.440 --> 00:22:40.590 align:start position:0% We<00:22:37.880> are<00:22:38.320> constantly<00:22:38.960> moving<00:22:39.360> through<00:22:39.600> space, 00:22:40.590 --> 00:22:40.600 align:start position:0% We are constantly moving through space, 00:22:40.600 --> 00:22:42.990 align:start position:0% We are constantly moving through space, but<00:22:40.840> even<00:22:41.320> the<00:22:41.440> science<00:22:41.960> of<00:22:42.080> space<00:22:42.415> [music]<00:22:42.720> is 00:22:42.990 --> 00:22:43.000 align:start position:0% but even the science of space [music] is 00:22:43.000 --> 00:22:44.710 align:start position:0% but even the science of space [music] is always<00:22:43.480> in<00:22:43.600> motion. 00:22:44.710 --> 00:22:44.720 align:start position:0% always in motion. 00:22:44.720 --> 00:22:46.950 align:start position:0% always in motion. Each<00:22:44.960> new<00:22:45.120> galaxy,<00:22:46.080> along<00:22:46.400> with<00:22:46.560> data 00:22:46.950 --> 00:22:46.960 align:start position:0% Each new galaxy, along with data 00:22:46.960 --> 00:22:49.550 align:start position:0% Each new galaxy, along with data regarding<00:22:47.560> its<00:22:47.760> redshift<00:22:48.320> and<00:22:48.440> travel<00:22:48.800> speed, 00:22:49.550 --> 00:22:49.560 align:start position:0% regarding its redshift and travel speed, 00:22:49.560 --> 00:22:52.150 align:start position:0% regarding its redshift and travel speed, helps<00:22:49.880> us<00:22:50.000> develop<00:22:50.640> a<00:22:50.720> broader<00:22:51.400> understanding 00:22:52.150 --> 00:22:52.160 align:start position:0% helps us develop a broader understanding 00:22:52.160 --> 00:22:54.230 align:start position:0% helps us develop a broader understanding of<00:22:52.320> the<00:22:52.400> movement<00:22:52.880> of<00:22:52.960> the<00:22:53.040> galaxy. 00:22:54.230 --> 00:22:54.240 align:start position:0% of the movement of the galaxy. 00:22:54.240 --> 00:22:56.470 align:start position:0% of the movement of the galaxy. It's<00:22:54.400> fascinating<00:22:55.000> to<00:22:55.120> think<00:22:55.760> that<00:22:55.920> not<00:22:56.240> all 00:22:56.470 --> 00:22:56.480 align:start position:0% It's fascinating to think that not all 00:22:56.480 --> 00:22:58.830 align:start position:0% It's fascinating to think that not all of<00:22:56.600> that<00:22:56.760> motion<00:22:57.360> is<00:22:57.560> caused<00:22:58.160> by<00:22:58.320> the<00:22:58.440> pull<00:22:58.680> of 00:22:58.830 --> 00:22:58.840 align:start position:0% of that motion is caused by the pull of 00:22:58.840 --> 00:23:00.190 align:start position:0% of that motion is caused by the pull of gravity. 00:23:00.190 --> 00:23:00.200 align:start position:0% gravity. 00:23:00.200 --> 00:23:02.950 align:start position:0% gravity. It<00:23:00.320> might<00:23:00.600> turn<00:23:00.880> out<00:23:01.280> that<00:23:01.640> sometimes<00:23:02.840> the 00:23:02.950 --> 00:23:02.960 align:start position:0% It might turn out that sometimes the 00:23:02.960 --> 00:23:05.390 align:start position:0% It might turn out that sometimes the universe<00:23:03.400> just<00:23:03.640> needs<00:23:03.960> a<00:23:04.040> little<00:23:04.400> push<00:23:05.040> to<00:23:05.200> get 00:23:05.390 --> 00:23:05.400 align:start position:0% universe just needs a little push to get 00:23:05.400 --> 00:23:13.630 align:start position:0% universe just needs a little push to get going. 00:23:13.630 --> 00:23:13.640 align:start position:0% 00:23:13.640 --> 00:23:15.750 align:start position:0% Tune<00:23:14.240> into<00:23:14.520> the<00:23:14.600> universe<00:23:15.200> with<00:23:15.320> the<00:23:15.440> right 00:23:15.750 --> 00:23:15.760 align:start position:0% Tune into the universe with the right 00:23:15.760 --> 00:23:18.470 align:start position:0% Tune into the universe with the right equipment<00:23:16.600> and<00:23:16.760> you<00:23:16.840> will<00:23:17.000> hear<00:23:17.400> it<00:23:17.680> humming 00:23:18.470 --> 00:23:18.480 align:start position:0% equipment and you will hear it humming 00:23:18.480 --> 00:23:21.150 align:start position:0% equipment and you will hear it humming no<00:23:18.640> matter<00:23:18.960> where<00:23:19.280> you<00:23:19.480> look<00:23:19.760> in<00:23:19.880> the<00:23:19.960> sky. 00:23:21.150 --> 00:23:21.160 align:start position:0% no matter where you look in the sky. 00:23:21.160 --> 00:23:23.270 align:start position:0% no matter where you look in the sky. Of<00:23:21.360> course,<00:23:22.000> it's<00:23:22.200> not<00:23:22.360> possible<00:23:22.840> for<00:23:22.960> sound 00:23:23.270 --> 00:23:23.280 align:start position:0% Of course, it's not possible for sound 00:23:23.280 --> 00:23:25.390 align:start position:0% Of course, it's not possible for sound to<00:23:23.320> travel<00:23:23.800> in<00:23:23.880> the<00:23:23.960> vacuum<00:23:24.320> of<00:23:24.440> space. 00:23:25.390 --> 00:23:25.400 align:start position:0% to travel in the vacuum of space. 00:23:25.400 --> 00:23:28.190 align:start position:0% to travel in the vacuum of space. Instead,<00:23:26.240> we<00:23:26.440> are<00:23:26.520> talking<00:23:26.920> about<00:23:27.200> the<00:23:27.320> hum<00:23:27.960> of 00:23:28.190 --> 00:23:28.200 align:start position:0% Instead, we are talking about the hum of 00:23:28.200 --> 00:23:30.910 align:start position:0% Instead, we are talking about the hum of gravitational<00:23:29.240> waves. 00:23:30.910 --> 00:23:30.920 align:start position:0% gravitational waves. 00:23:30.920 --> 00:23:32.870 align:start position:0% gravitational waves. You<00:23:31.120> might<00:23:31.480> already<00:23:31.960> be<00:23:32.120> familiar<00:23:32.640> with<00:23:32.840> a 00:23:32.870 --> 00:23:32.880 align:start position:0% You might already be familiar with a 00:23:32.880 --> 00:23:35.510 align:start position:0% You might already be familiar with a similar<00:23:33.320> signal<00:23:33.840> discovered<00:23:34.280> decades<00:23:34.720> ago. 00:23:35.510 --> 00:23:35.520 align:start position:0% similar signal discovered decades ago. 00:23:35.520 --> 00:23:37.470 align:start position:0% similar signal discovered decades ago. It's<00:23:35.720> called<00:23:35.920> the<00:23:36.000> cosmic<00:23:36.680> microwave 00:23:37.470 --> 00:23:37.480 align:start position:0% It's called the cosmic microwave 00:23:37.480 --> 00:23:39.790 align:start position:0% It's called the cosmic microwave background<00:23:38.440> and<00:23:38.560> it<00:23:38.720> is<00:23:38.840> the<00:23:39.040> afterglow<00:23:39.680> of 00:23:39.790 --> 00:23:39.800 align:start position:0% background and it is the afterglow of 00:23:39.800 --> 00:23:41.350 align:start position:0% background and it is the afterglow of the<00:23:39.920> Big<00:23:40.120> Bang. 00:23:41.350 --> 00:23:41.360 align:start position:0% the Big Bang. 00:23:41.360 --> 00:23:43.430 align:start position:0% the Big Bang. This<00:23:41.680> glow<00:23:42.160> of<00:23:42.320> microwave<00:23:42.920> light<00:23:43.280> was<00:23:43.400> a 00:23:43.430 --> 00:23:43.440 align:start position:0% This glow of microwave light was a 00:23:43.440 --> 00:23:45.630 align:start position:0% This glow of microwave light was a groundbreaking<00:23:44.120> discovery.<00:23:45.200> It<00:23:45.360> was<00:23:45.520> the 00:23:45.630 --> 00:23:45.640 align:start position:0% groundbreaking discovery. It was the 00:23:45.640 --> 00:23:48.070 align:start position:0% groundbreaking discovery. It was the smoking<00:23:46.280> gun<00:23:46.800> that<00:23:46.960> solidified<00:23:47.640> the<00:23:47.720> Big 00:23:48.070 --> 00:23:48.080 align:start position:0% smoking gun that solidified the Big 00:23:48.080 --> 00:23:50.390 align:start position:0% smoking gun that solidified the Big Bang's<00:23:48.360> place<00:23:48.960> as<00:23:49.160> the<00:23:49.320> leading<00:23:49.720> theory<00:23:50.160> of 00:23:50.390 --> 00:23:50.400 align:start position:0% Bang's place as the leading theory of 00:23:50.400 --> 00:23:52.510 align:start position:0% Bang's place as the leading theory of our<00:23:50.560> universe's<00:23:51.200> beginning. 00:23:52.510 --> 00:23:52.520 align:start position:0% our universe's beginning. 00:23:52.520 --> 00:23:55.590 align:start position:0% our universe's beginning. Yet,<00:23:53.440> this<00:23:53.720> light<00:23:54.000> signal<00:23:54.440> had<00:23:54.840> a<00:23:54.920> glaring 00:23:55.590 --> 00:23:55.600 align:start position:0% Yet, this light signal had a glaring 00:23:55.600 --> 00:23:56.710 align:start position:0% Yet, this light signal had a glaring weakness. 00:23:56.710 --> 00:23:56.720 align:start position:0% weakness. 00:23:56.720 --> 00:23:59.110 align:start position:0% weakness. Despite<00:23:57.360> it<00:23:57.480> being<00:23:57.760> the<00:23:58.040> earliest<00:23:58.560> light<00:23:58.920> of 00:23:59.110 --> 00:23:59.120 align:start position:0% Despite it being the earliest light of 00:23:59.120 --> 00:24:01.550 align:start position:0% Despite it being the earliest light of our<00:23:59.280> universe,<00:24:00.280> it<00:24:00.480> was<00:24:00.640> emitted<00:24:01.160> almost 00:24:01.550 --> 00:24:01.560 align:start position:0% our universe, it was emitted almost 00:24:01.560 --> 00:24:03.350 align:start position:0% our universe, it was emitted almost 400,000 00:24:03.350 --> 00:24:03.360 align:start position:0% 400,000 00:24:03.360 --> 00:24:06.110 align:start position:0% 400,000 years<00:24:03.960> after<00:24:04.440> the<00:24:04.560> Big<00:24:04.720> Bang. 00:24:06.110 --> 00:24:06.120 align:start position:0% years after the Big Bang. 00:24:06.120 --> 00:24:08.710 align:start position:0% years after the Big Bang. If<00:24:06.360> we<00:24:06.480> want<00:24:06.680> to<00:24:06.760> go<00:24:06.960> back<00:24:07.440> earlier,<00:24:08.480> we<00:24:08.600> will 00:24:08.710 --> 00:24:08.720 align:start position:0% If we want to go back earlier, we will 00:24:08.720 --> 00:24:10.990 align:start position:0% If we want to go back earlier, we will need<00:24:09.080> a<00:24:09.160> background<00:24:09.680> signal<00:24:10.360> made<00:24:10.640> not<00:24:10.880> of 00:24:10.990 --> 00:24:11.000 align:start position:0% need a background signal made not of 00:24:11.000 --> 00:24:13.790 align:start position:0% need a background signal made not of light,<00:24:11.880> but<00:24:12.080> of<00:24:12.200> the<00:24:12.320> ripples<00:24:12.920> of<00:24:13.080> the<00:24:13.200> fabric 00:24:13.790 --> 00:24:13.800 align:start position:0% light, but of the ripples of the fabric 00:24:13.800 --> 00:24:16.190 align:start position:0% light, but of the ripples of the fabric of<00:24:13.960> space-time. 00:24:16.190 --> 00:24:16.200 align:start position:0% of space-time. 00:24:16.200 --> 00:24:19.310 align:start position:0% of space-time. In<00:24:16.480> 2023,<00:24:17.840> astronomers<00:24:18.480> at<00:24:18.600> the<00:24:18.680> NANOGrav 00:24:19.310 --> 00:24:19.320 align:start position:0% In 2023, astronomers at the NANOGrav 00:24:19.320 --> 00:24:21.470 align:start position:0% In 2023, astronomers at the NANOGrav collaboration<00:24:20.200> have<00:24:20.360> announced<00:24:20.880> that<00:24:21.280> by 00:24:21.470 --> 00:24:21.480 align:start position:0% collaboration have announced that by 00:24:21.480 --> 00:24:23.750 align:start position:0% collaboration have announced that by using<00:24:21.880> a<00:24:21.960> clever<00:24:22.240> trick,<00:24:23.040> they<00:24:23.240> may<00:24:23.600> have 00:24:23.750 --> 00:24:23.760 align:start position:0% using a clever trick, they may have 00:24:23.760 --> 00:24:26.390 align:start position:0% using a clever trick, they may have detected<00:24:24.520> just<00:24:24.920> that. 00:24:26.390 --> 00:24:26.400 align:start position:0% detected just that. 00:24:26.400 --> 00:24:29.190 align:start position:0% detected just that. Using<00:24:26.880> exotic<00:24:27.440> stars<00:24:27.960> as<00:24:28.120> a<00:24:28.160> galactic<00:24:28.840> size 00:24:29.190 --> 00:24:29.200 align:start position:0% Using exotic stars as a galactic size 00:24:29.200 --> 00:24:31.310 align:start position:0% Using exotic stars as a galactic size gravitational<00:24:29.920> wave<00:24:30.160> detector,<00:24:31.160> they 00:24:31.310 --> 00:24:31.320 align:start position:0% gravitational wave detector, they 00:24:31.320 --> 00:24:33.270 align:start position:0% gravitational wave detector, they measured<00:24:31.760> the<00:24:31.880> faint<00:24:32.200> hum<00:24:32.520> of<00:24:32.680> space-time 00:24:33.270 --> 00:24:33.280 align:start position:0% measured the faint hum of space-time 00:24:33.280 --> 00:24:34.470 align:start position:0% measured the faint hum of space-time itself. 00:24:34.470 --> 00:24:34.480 align:start position:0% itself. 00:24:34.480 --> 00:24:36.870 align:start position:0% itself. This<00:24:34.800> hum<00:24:35.040> of<00:24:35.160> gravitational<00:24:35.840> waves<00:24:36.520> might 00:24:36.870 --> 00:24:36.880 align:start position:0% This hum of gravitational waves might 00:24:36.880 --> 00:24:39.510 align:start position:0% This hum of gravitational waves might just<00:24:37.200> be<00:24:37.600> the<00:24:37.720> reverberations<00:24:38.640> of<00:24:38.800> the<00:24:38.960> very 00:24:39.510 --> 00:24:39.520 align:start position:0% just be the reverberations of the very 00:24:39.520 --> 00:24:43.350 align:start position:0% just be the reverberations of the very creation<00:24:40.360> of<00:24:40.720> our<00:24:40.880> universe. 00:24:43.350 --> 00:24:43.360 align:start position:0% creation of our universe. 00:24:43.360 --> 00:24:45.510 align:start position:0% creation of our universe. I'm<00:24:43.840> Alex<00:24:44.120> Mackolgan<00:24:44.840> and<00:24:45.000> you're<00:24:45.160> watching 00:24:45.510 --> 00:24:45.520 align:start position:0% I'm Alex Mackolgan and you're watching 00:24:45.520 --> 00:24:48.030 align:start position:0% I'm Alex Mackolgan and you're watching Astrium.<00:24:46.440> Join<00:24:46.720> me<00:24:46.840> today<00:24:47.200> as<00:24:47.400> we<00:24:47.520> learn<00:24:47.800> about 00:24:48.030 --> 00:24:48.040 align:start position:0% Astrium. Join me today as we learn about 00:24:48.040 --> 00:24:50.630 align:start position:0% Astrium. Join me today as we learn about the<00:24:48.160> secrets<00:24:48.840> of<00:24:49.040> gargantuan<00:24:50.000> gravitational 00:24:50.630 --> 00:24:50.640 align:start position:0% the secrets of gargantuan gravitational 00:24:50.640 --> 00:24:53.230 align:start position:0% the secrets of gargantuan gravitational waves<00:24:51.480> and<00:24:51.640> the<00:24:51.760> ingenious<00:24:52.560> new<00:24:52.760> method 00:24:53.230 --> 00:24:53.240 align:start position:0% waves and the ingenious new method 00:24:53.240 --> 00:24:57.830 align:start position:0% waves and the ingenious new method astronomers<00:24:53.800> have<00:24:53.960> used<00:24:54.280> to<00:24:54.360> detect<00:24:54.760> them. 00:24:57.830 --> 00:24:57.840 align:start position:0% 00:24:57.840 --> 00:25:00.150 align:start position:0% In<00:24:58.040> a<00:24:58.120> previous<00:24:58.600> episode,<00:24:59.400> we<00:24:59.640> covered<00:25:00.040> the 00:25:00.150 --> 00:25:00.160 align:start position:0% In a previous episode, we covered the 00:25:00.160 --> 00:25:02.750 align:start position:0% In a previous episode, we covered the LIGO<00:25:00.520> detector<00:25:01.160> and<00:25:01.320> how<00:25:01.600> it<00:25:01.760> uses<00:25:02.120> lasers<00:25:02.640> to 00:25:02.750 --> 00:25:02.760 align:start position:0% LIGO detector and how it uses lasers to 00:25:02.760 --> 00:25:05.110 align:start position:0% LIGO detector and how it uses lasers to precisely<00:25:03.240> measure<00:25:03.680> the<00:25:03.840> minuscule<00:25:04.600> changes 00:25:05.110 --> 00:25:05.120 align:start position:0% precisely measure the minuscule changes 00:25:05.120 --> 00:25:07.150 align:start position:0% precisely measure the minuscule changes in<00:25:05.280> the<00:25:05.400> length<00:25:05.800> of<00:25:05.920> a<00:25:05.960> tunnel<00:25:06.680> caused<00:25:07.040> by 00:25:07.150 --> 00:25:07.160 align:start position:0% in the length of a tunnel caused by 00:25:07.160 --> 00:25:10.110 align:start position:0% in the length of a tunnel caused by gravitational<00:25:07.880> waves<00:25:08.320> passing<00:25:08.800> through. 00:25:10.110 --> 00:25:10.120 align:start position:0% gravitational waves passing through. 00:25:10.120 --> 00:25:12.550 align:start position:0% gravitational waves passing through. These<00:25:10.320> gravitational<00:25:10.960> waves<00:25:11.440> stretch<00:25:12.320> and 00:25:12.550 --> 00:25:12.560 align:start position:0% These gravitational waves stretch and 00:25:12.560 --> 00:25:15.550 align:start position:0% These gravitational waves stretch and squish<00:25:13.280> space-time<00:25:14.320> causing<00:25:14.760> changes<00:25:15.320> in<00:25:15.440> the 00:25:15.550 --> 00:25:15.560 align:start position:0% squish space-time causing changes in the 00:25:15.560 --> 00:25:17.310 align:start position:0% squish space-time causing changes in the time<00:25:15.880> it<00:25:16.000> takes<00:25:16.240> for<00:25:16.400> light<00:25:16.640> to<00:25:16.720> travel<00:25:17.040> from 00:25:17.310 --> 00:25:17.320 align:start position:0% time it takes for light to travel from 00:25:17.320 --> 00:25:19.870 align:start position:0% time it takes for light to travel from one<00:25:17.560> end<00:25:17.760> of<00:25:17.840> the<00:25:17.920> tunnel<00:25:18.360> to<00:25:18.480> the<00:25:18.640> other. 00:25:19.870 --> 00:25:19.880 align:start position:0% one end of the tunnel to the other. 00:25:19.880 --> 00:25:21.830 align:start position:0% one end of the tunnel to the other. But<00:25:20.000> detectors<00:25:20.440> like<00:25:20.680> LIGO<00:25:21.240> are<00:25:21.560> only 00:25:21.830 --> 00:25:21.840 align:start position:0% But detectors like LIGO are only 00:25:21.840 --> 00:25:24.310 align:start position:0% But detectors like LIGO are only sensitive<00:25:22.440> to<00:25:22.720> a<00:25:22.840> specific<00:25:23.760> kind<00:25:24.200> of 00:25:24.310 --> 00:25:24.320 align:start position:0% sensitive to a specific kind of 00:25:24.320 --> 00:25:26.190 align:start position:0% sensitive to a specific kind of gravitational<00:25:25.000> waves. 00:25:26.190 --> 00:25:26.200 align:start position:0% gravitational waves. 00:25:26.200 --> 00:25:27.990 align:start position:0% gravitational waves. Like<00:25:26.440> light<00:25:26.680> waves<00:25:26.960> and<00:25:27.120> sound<00:25:27.360> waves, 00:25:27.990 --> 00:25:28.000 align:start position:0% Like light waves and sound waves, 00:25:28.000 --> 00:25:29.750 align:start position:0% Like light waves and sound waves, gravitational<00:25:28.640> waves<00:25:28.960> can<00:25:29.120> come<00:25:29.520> in 00:25:29.750 --> 00:25:29.760 align:start position:0% gravitational waves can come in 00:25:29.760 --> 00:25:32.670 align:start position:0% gravitational waves can come in different<00:25:30.240> frequencies<00:25:31.440> and<00:25:31.560> LIGO<00:25:32.000> is<00:25:32.280> only 00:25:32.670 --> 00:25:32.680 align:start position:0% different frequencies and LIGO is only 00:25:32.680 --> 00:25:35.070 align:start position:0% different frequencies and LIGO is only able<00:25:32.960> to<00:25:33.080> listen<00:25:33.480> in<00:25:33.960> to<00:25:34.240> one<00:25:34.520> part<00:25:34.880> of<00:25:34.960> the 00:25:35.070 --> 00:25:35.080 align:start position:0% able to listen in to one part of the 00:25:35.080 --> 00:25:38.630 align:start position:0% able to listen in to one part of the spectrum,<00:25:36.120> the<00:25:36.320> high<00:25:36.600> frequencies. 00:25:38.630 --> 00:25:38.640 align:start position:0% spectrum, the high frequencies. 00:25:38.640 --> 00:25:40.990 align:start position:0% spectrum, the high frequencies. That's<00:25:38.840> when<00:25:39.120> these<00:25:39.400> binaries<00:25:40.080> are<00:25:40.240> spiraling 00:25:40.990 --> 00:25:41.000 align:start position:0% That's when these binaries are spiraling 00:25:41.000 --> 00:25:43.070 align:start position:0% That's when these binaries are spiraling in<00:25:41.160> on<00:25:41.280> each<00:25:41.440> other<00:25:41.640> rapidly,<00:25:42.560> completing 00:25:43.070 --> 00:25:43.080 align:start position:0% in on each other rapidly, completing 00:25:43.080 --> 00:25:45.830 align:start position:0% in on each other rapidly, completing hundreds<00:25:43.680> of<00:25:43.800> rotations<00:25:44.480> per<00:25:44.760> second<00:25:45.560> before 00:25:45.830 --> 00:25:45.840 align:start position:0% hundreds of rotations per second before 00:25:45.840 --> 00:25:49.310 align:start position:0% hundreds of rotations per second before colliding<00:25:46.680> in<00:25:46.800> a<00:25:46.880> great<00:25:47.560> bang. 00:25:49.310 --> 00:25:49.320 align:start position:0% colliding in a great bang. 00:25:49.320 --> 00:25:51.430 align:start position:0% colliding in a great bang. But<00:25:49.440> that<00:25:49.640> is<00:25:49.760> also<00:25:50.080> why<00:25:50.280> LIGO<00:25:50.800> cannot<00:25:51.160> listen 00:25:51.430 --> 00:25:51.440 align:start position:0% But that is also why LIGO cannot listen 00:25:51.440 --> 00:25:53.590 align:start position:0% But that is also why LIGO cannot listen in<00:25:51.760> on<00:25:51.880> the<00:25:51.960> much<00:25:52.360> earlier<00:25:52.800> stages<00:25:53.280> of<00:25:53.400> these 00:25:53.590 --> 00:25:53.600 align:start position:0% in on the much earlier stages of these 00:25:53.600 --> 00:25:56.070 align:start position:0% in on the much earlier stages of these binaries<00:25:54.600> when<00:25:54.800> the<00:25:54.920> objects<00:25:55.520> are<00:25:55.720> orbiting 00:25:56.070 --> 00:25:56.080 align:start position:0% binaries when the objects are orbiting 00:25:56.080 --> 00:25:59.070 align:start position:0% binaries when the objects are orbiting each<00:25:56.280> other<00:25:56.520> at<00:25:56.680> a<00:25:56.720> much<00:25:57.040> greater<00:25:57.560> distance. 00:25:59.070 --> 00:25:59.080 align:start position:0% each other at a much greater distance. 00:25:59.080 --> 00:26:01.670 align:start position:0% each other at a much greater distance. Because<00:25:59.360> these<00:25:59.600> orbits<00:26:00.080> are<00:26:00.320> much<00:26:00.800> slower, 00:26:01.670 --> 00:26:01.680 align:start position:0% Because these orbits are much slower, 00:26:01.680 --> 00:26:03.710 align:start position:0% Because these orbits are much slower, the<00:26:01.760> gravitational<00:26:02.480> waves<00:26:02.760> they<00:26:02.920> produce<00:26:03.480> are 00:26:03.710 --> 00:26:03.720 align:start position:0% the gravitational waves they produce are 00:26:03.720 --> 00:26:06.350 align:start position:0% the gravitational waves they produce are of<00:26:04.000> a<00:26:04.120> lower<00:26:04.520> frequency<00:26:05.080> and<00:26:05.200> energy. 00:26:06.350 --> 00:26:06.360 align:start position:0% of a lower frequency and energy. 00:26:06.360 --> 00:26:08.350 align:start position:0% of a lower frequency and energy. So<00:26:06.520> you<00:26:06.640> could<00:26:06.840> say,<00:26:07.480> rather<00:26:07.800> than<00:26:07.960> a<00:26:08.000> great 00:26:08.350 --> 00:26:08.360 align:start position:0% So you could say, rather than a great 00:26:08.360 --> 00:26:11.230 align:start position:0% So you could say, rather than a great bang,<00:26:09.160> they<00:26:09.280> give<00:26:09.520> off<00:26:09.760> a<00:26:09.840> faint<00:26:10.360> hum 00:26:11.230 --> 00:26:11.240 align:start position:0% bang, they give off a faint hum 00:26:11.240 --> 00:26:15.030 align:start position:0% bang, they give off a faint hum combining<00:26:11.920> into<00:26:12.200> one<00:26:12.720> collective<00:26:13.320> signal. 00:26:15.030 --> 00:26:15.040 align:start position:0% combining into one collective signal. 00:26:15.040 --> 00:26:16.910 align:start position:0% combining into one collective signal. Bigger<00:26:15.280> black<00:26:15.600> holes<00:26:16.160> give<00:26:16.400> greater 00:26:16.910 --> 00:26:16.920 align:start position:0% Bigger black holes give greater 00:26:16.920 --> 00:26:19.190 align:start position:0% Bigger black holes give greater contributions<00:26:17.640> to<00:26:17.760> this<00:26:17.920> signal. 00:26:19.190 --> 00:26:19.200 align:start position:0% contributions to this signal. 00:26:19.200 --> 00:26:21.350 align:start position:0% contributions to this signal. The<00:26:19.360> loudest<00:26:19.840> contributors<00:26:20.720> would<00:26:20.880> consist 00:26:21.350 --> 00:26:21.360 align:start position:0% The loudest contributors would consist 00:26:21.360 --> 00:26:24.270 align:start position:0% The loudest contributors would consist of<00:26:21.520> pairs<00:26:22.040> of<00:26:22.320> supermassive<00:26:23.200> black<00:26:23.480> holes, 00:26:24.270 --> 00:26:24.280 align:start position:0% of pairs of supermassive black holes, 00:26:24.280 --> 00:26:26.030 align:start position:0% of pairs of supermassive black holes, the<00:26:24.400> kind<00:26:24.680> you'd<00:26:24.880> find<00:26:25.240> at<00:26:25.360> the<00:26:25.440> center<00:26:25.840> of 00:26:26.030 --> 00:26:26.040 align:start position:0% the kind you'd find at the center of 00:26:26.040 --> 00:26:27.790 align:start position:0% the kind you'd find at the center of galaxies. 00:26:27.790 --> 00:26:27.800 align:start position:0% galaxies. 00:26:27.800 --> 00:26:30.110 align:start position:0% galaxies. These<00:26:28.120> binaries,<00:26:29.040> which<00:26:29.240> consist<00:26:29.680> of<00:26:29.800> black 00:26:30.110 --> 00:26:30.120 align:start position:0% These binaries, which consist of black 00:26:30.120 --> 00:26:32.510 align:start position:0% These binaries, which consist of black holes<00:26:30.680> billions<00:26:31.240> of<00:26:31.360> times<00:26:31.760> the<00:26:31.840> mass<00:26:32.120> of<00:26:32.320> our 00:26:32.510 --> 00:26:32.520 align:start position:0% holes billions of times the mass of our 00:26:32.520 --> 00:26:35.310 align:start position:0% holes billions of times the mass of our sun,<00:26:33.320> are<00:26:33.480> expected<00:26:34.000> to<00:26:34.080> be<00:26:34.200> rare<00:26:34.920> cuz<00:26:35.120> they 00:26:35.310 --> 00:26:35.320 align:start position:0% sun, are expected to be rare cuz they 00:26:35.320 --> 00:26:37.150 align:start position:0% sun, are expected to be rare cuz they only<00:26:35.600> form<00:26:35.960> when<00:26:36.160> something<00:26:36.560> truly 00:26:37.150 --> 00:26:37.160 align:start position:0% only form when something truly 00:26:37.160 --> 00:26:40.390 align:start position:0% only form when something truly spectacular<00:26:37.920> happens,<00:26:38.800> the<00:26:38.960> merger<00:26:39.760> of<00:26:40.080> two 00:26:40.390 --> 00:26:40.400 align:start position:0% spectacular happens, the merger of two 00:26:40.400 --> 00:26:42.550 align:start position:0% spectacular happens, the merger of two galaxies. 00:26:42.550 --> 00:26:42.560 align:start position:0% galaxies. 00:26:42.560 --> 00:26:45.270 align:start position:0% galaxies. When<00:26:42.840> galaxies<00:26:43.360> merge,<00:26:44.160> because<00:26:44.520> of<00:26:44.600> the<00:26:44.720> vast 00:26:45.270 --> 00:26:45.280 align:start position:0% When galaxies merge, because of the vast 00:26:45.280 --> 00:26:47.510 align:start position:0% When galaxies merge, because of the vast amounts<00:26:45.760> of<00:26:45.960> empty<00:26:46.360> interstellar<00:26:46.920> space<00:26:47.320> in 00:26:47.510 --> 00:26:47.520 align:start position:0% amounts of empty interstellar space in 00:26:47.520 --> 00:26:49.670 align:start position:0% amounts of empty interstellar space in them,<00:26:48.200> they<00:26:48.320> mostly<00:26:48.840> phase<00:26:49.200> through<00:26:49.480> each 00:26:49.670 --> 00:26:49.680 align:start position:0% them, they mostly phase through each 00:26:49.680 --> 00:26:50.790 align:start position:0% them, they mostly phase through each other. 00:26:50.790 --> 00:26:50.800 align:start position:0% other. 00:26:50.800 --> 00:26:53.830 align:start position:0% other. Very<00:26:51.160> few,<00:26:51.840> if<00:26:52.160> any,<00:26:52.800> actual<00:26:53.200> collisions<00:26:53.720> of 00:26:53.830 --> 00:26:53.840 align:start position:0% Very few, if any, actual collisions of 00:26:53.840 --> 00:26:56.190 align:start position:0% Very few, if any, actual collisions of stars<00:26:54.320> or<00:26:54.440> planets<00:26:54.840> happen. 00:26:56.190 --> 00:26:56.200 align:start position:0% stars or planets happen. 00:26:56.200 --> 00:26:58.710 align:start position:0% stars or planets happen. But,<00:26:56.680> the<00:26:56.800> stars<00:26:57.240> gravitationally<00:26:58.320> attract 00:26:58.710 --> 00:26:58.720 align:start position:0% But, the stars gravitationally attract 00:26:58.720 --> 00:27:00.990 align:start position:0% But, the stars gravitationally attract one<00:26:58.840> another<00:26:59.600> and<00:26:59.840> merge<00:27:00.320> into<00:27:00.600> one 00:27:00.990 --> 00:27:01.000 align:start position:0% one another and merge into one 00:27:01.000 --> 00:27:02.990 align:start position:0% one another and merge into one collective<00:27:01.600> galaxy. 00:27:02.990 --> 00:27:03.000 align:start position:0% collective galaxy. 00:27:03.000 --> 00:27:05.590 align:start position:0% collective galaxy. And<00:27:03.320> the<00:27:03.520> nuclei<00:27:04.120> of<00:27:04.240> these<00:27:04.440> galaxies,<00:27:05.480> the 00:27:05.590 --> 00:27:05.600 align:start position:0% And the nuclei of these galaxies, the 00:27:05.600 --> 00:27:08.550 align:start position:0% And the nuclei of these galaxies, the supermassive<00:27:06.200> black<00:27:06.520> holes,<00:27:07.320> form<00:27:07.600> binaries 00:27:08.550 --> 00:27:08.560 align:start position:0% supermassive black holes, form binaries 00:27:08.560 --> 00:27:11.070 align:start position:0% supermassive black holes, form binaries that<00:27:08.680> continue<00:27:09.320> orbiting<00:27:09.880> one<00:27:10.080> another<00:27:10.560> long 00:27:11.070 --> 00:27:11.080 align:start position:0% that continue orbiting one another long 00:27:11.080 --> 00:27:13.110 align:start position:0% that continue orbiting one another long after<00:27:11.360> the<00:27:11.440> galaxy<00:27:11.840> merger<00:27:12.280> appears<00:27:12.880> to<00:27:13.000> be 00:27:13.110 --> 00:27:13.120 align:start position:0% after the galaxy merger appears to be 00:27:13.120 --> 00:27:14.550 align:start position:0% after the galaxy merger appears to be complete. 00:27:14.550 --> 00:27:14.560 align:start position:0% complete. 00:27:14.560 --> 00:27:16.470 align:start position:0% complete. It's<00:27:14.720> these<00:27:14.960> remnants<00:27:15.480> of<00:27:15.560> galaxy<00:27:15.960> mergers 00:27:16.470 --> 00:27:16.480 align:start position:0% It's these remnants of galaxy mergers 00:27:16.480 --> 00:27:18.710 align:start position:0% It's these remnants of galaxy mergers that<00:27:16.640> we<00:27:16.800> would<00:27:16.960> hear<00:27:17.400> most<00:27:17.720> strongly<00:27:18.320> in<00:27:18.520> the 00:27:18.710 --> 00:27:18.720 align:start position:0% that we would hear most strongly in the 00:27:18.720 --> 00:27:21.910 align:start position:0% that we would hear most strongly in the ultra-low<00:27:19.520> frequency<00:27:20.160> range,<00:27:21.000> specifically 00:27:21.910 --> 00:27:21.920 align:start position:0% ultra-low frequency range, specifically 00:27:21.920 --> 00:27:24.270 align:start position:0% ultra-low frequency range, specifically around<00:27:22.360> the<00:27:22.480> nanohertz<00:27:23.120> range. 00:27:24.270 --> 00:27:24.280 align:start position:0% around the nanohertz range. 00:27:24.280 --> 00:27:27.070 align:start position:0% around the nanohertz range. Yet,<00:27:25.280> just<00:27:25.600> like<00:27:25.960> how<00:27:26.120> the<00:27:26.240> human<00:27:26.560> ear<00:27:26.800> cannot 00:27:27.070 --> 00:27:27.080 align:start position:0% Yet, just like how the human ear cannot 00:27:27.080 --> 00:27:29.590 align:start position:0% Yet, just like how the human ear cannot hear<00:27:27.320> sounds<00:27:27.640> with<00:27:27.840> ultra-low<00:27:28.400> frequencies, 00:27:29.590 --> 00:27:29.600 align:start position:0% hear sounds with ultra-low frequencies, 00:27:29.600 --> 00:27:33.830 align:start position:0% hear sounds with ultra-low frequencies, LIGO<00:27:30.200> is<00:27:30.440> deaf<00:27:31.120> to<00:27:31.240> this<00:27:31.440> cosmic<00:27:32.120> cacophony. 00:27:33.830 --> 00:27:33.840 align:start position:0% LIGO is deaf to this cosmic cacophony. 00:27:33.840 --> 00:27:36.510 align:start position:0% LIGO is deaf to this cosmic cacophony. If<00:27:34.080> we<00:27:34.280> could<00:27:34.600> listen<00:27:34.960> in,<00:27:35.560> we<00:27:35.680> would<00:27:35.840> gain<00:27:36.200> new 00:27:36.510 --> 00:27:36.520 align:start position:0% If we could listen in, we would gain new 00:27:36.520 --> 00:27:38.790 align:start position:0% If we could listen in, we would gain new insight<00:27:37.120> into<00:27:37.360> galaxy<00:27:37.840> mergers<00:27:38.400> and<00:27:38.520> black 00:27:38.790 --> 00:27:38.800 align:start position:0% insight into galaxy mergers and black 00:27:38.800 --> 00:27:40.070 align:start position:0% insight into galaxy mergers and black holes. 00:27:40.070 --> 00:27:40.080 align:start position:0% holes. 00:27:40.080 --> 00:27:42.230 align:start position:0% holes. But,<00:27:40.560> that's<00:27:40.880> not<00:27:41.160> all. 00:27:42.230 --> 00:27:42.240 align:start position:0% But, that's not all. 00:27:42.240 --> 00:27:44.110 align:start position:0% But, that's not all. One<00:27:42.400> of<00:27:42.480> the<00:27:42.560> most<00:27:42.880> exciting<00:27:43.560> things<00:27:43.880> about 00:27:44.110 --> 00:27:44.120 align:start position:0% One of the most exciting things about 00:27:44.120 --> 00:27:46.230 align:start position:0% One of the most exciting things about the<00:27:44.200> gravitational<00:27:45.000> wave<00:27:45.280> background<00:27:46.120> is 00:27:46.230 --> 00:27:46.240 align:start position:0% the gravitational wave background is 00:27:46.240 --> 00:27:48.590 align:start position:0% the gravitational wave background is that<00:27:46.440> it<00:27:46.600> is<00:27:46.800> a<00:27:46.920> window<00:27:47.520> to<00:27:47.680> the<00:27:47.800> very<00:27:48.240> first 00:27:48.590 --> 00:27:48.600 align:start position:0% that it is a window to the very first 00:27:48.600 --> 00:27:52.630 align:start position:0% that it is a window to the very first moments<00:27:49.160> of<00:27:49.360> our<00:27:49.600> universe's<00:27:50.400> existence. 00:27:52.630 --> 00:27:52.640 align:start position:0% moments of our universe's existence. 00:27:52.640 --> 00:27:54.910 align:start position:0% moments of our universe's existence. Let's<00:27:53.000> quickly<00:27:53.480> recap<00:27:54.080> what<00:27:54.320> we<00:27:54.440> know<00:27:54.680> about 00:27:54.910 --> 00:27:54.920 align:start position:0% Let's quickly recap what we know about 00:27:54.920 --> 00:27:57.550 align:start position:0% Let's quickly recap what we know about the<00:27:55.000> cosmic<00:27:55.600> microwave<00:27:56.200> background. 00:27:57.550 --> 00:27:57.560 align:start position:0% the cosmic microwave background. 00:27:57.560 --> 00:27:59.670 align:start position:0% the cosmic microwave background. This<00:27:57.760> microwave<00:27:58.360> light<00:27:58.720> is<00:27:58.920> the<00:27:59.200> earliest 00:27:59.670 --> 00:27:59.680 align:start position:0% This microwave light is the earliest 00:27:59.680 --> 00:28:01.790 align:start position:0% This microwave light is the earliest light<00:28:00.040> that<00:28:00.160> we<00:28:00.280> can<00:28:00.400> detect<00:28:01.120> because<00:28:01.520> for<00:28:01.720> the 00:28:01.790 --> 00:28:01.800 align:start position:0% light that we can detect because for the 00:28:01.800 --> 00:28:04.870 align:start position:0% light that we can detect because for the first<00:28:02.200> 400,000<00:28:03.360> years,<00:28:04.040> the<00:28:04.160> universe<00:28:04.640> was 00:28:04.870 --> 00:28:04.880 align:start position:0% first 400,000 years, the universe was 00:28:04.880 --> 00:28:06.870 align:start position:0% first 400,000 years, the universe was opaque<00:28:05.360> to<00:28:05.520> light. 00:28:06.870 --> 00:28:06.880 align:start position:0% opaque to light. 00:28:06.880 --> 00:28:08.590 align:start position:0% opaque to light. What<00:28:07.000> does<00:28:07.120> it<00:28:07.240> mean<00:28:07.560> for<00:28:07.680> the<00:28:07.800> universe<00:28:08.240> to<00:28:08.360> be 00:28:08.590 --> 00:28:08.600 align:start position:0% What does it mean for the universe to be 00:28:08.600 --> 00:28:09.910 align:start position:0% What does it mean for the universe to be opaque? 00:28:09.910 --> 00:28:09.920 align:start position:0% opaque? 00:28:09.920 --> 00:28:12.910 align:start position:0% opaque? Initially,<00:28:10.800> the<00:28:10.920> universe<00:28:11.480> was<00:28:11.760> far<00:28:12.280> too<00:28:12.520> hot 00:28:12.910 --> 00:28:12.920 align:start position:0% Initially, the universe was far too hot 00:28:12.920 --> 00:28:15.430 align:start position:0% Initially, the universe was far too hot for<00:28:13.080> neutral<00:28:13.520> matter<00:28:13.880> to<00:28:14.040> exist. 00:28:15.430 --> 00:28:15.440 align:start position:0% for neutral matter to exist. 00:28:15.440 --> 00:28:17.550 align:start position:0% for neutral matter to exist. Electrons<00:28:16.040> and<00:28:16.160> protons<00:28:16.720> were<00:28:17.000> unable<00:28:17.480> to 00:28:17.550 --> 00:28:17.560 align:start position:0% Electrons and protons were unable to 00:28:17.560 --> 00:28:20.190 align:start position:0% Electrons and protons were unable to bind<00:28:17.840> together<00:28:18.480> and<00:28:18.640> form<00:28:18.920> neutral<00:28:19.440> atoms 00:28:20.190 --> 00:28:20.200 align:start position:0% bind together and form neutral atoms 00:28:20.200 --> 00:28:23.110 align:start position:0% bind together and form neutral atoms simply<00:28:20.640> because<00:28:21.040> they<00:28:21.200> had<00:28:21.480> too<00:28:21.760> much<00:28:22.040> energy. 00:28:23.110 --> 00:28:23.120 align:start position:0% simply because they had too much energy. 00:28:23.120 --> 00:28:25.670 align:start position:0% simply because they had too much energy. This<00:28:23.320> state<00:28:23.640> of<00:28:23.760> matter<00:28:24.080> is<00:28:24.240> called<00:28:24.600> plasma, 00:28:25.670 --> 00:28:25.680 align:start position:0% This state of matter is called plasma, 00:28:25.680 --> 00:28:27.910 align:start position:0% This state of matter is called plasma, the<00:28:25.760> same<00:28:26.000> stuff<00:28:26.360> that<00:28:26.560> stars<00:28:26.960> are<00:28:27.040> made<00:28:27.320> of, 00:28:27.910 --> 00:28:27.920 align:start position:0% the same stuff that stars are made of, 00:28:27.920 --> 00:28:31.390 align:start position:0% the same stuff that stars are made of, and<00:28:28.040> the<00:28:28.120> universe<00:28:28.920> was<00:28:29.200> filled<00:28:29.640> with<00:28:29.800> it. 00:28:31.390 --> 00:28:31.400 align:start position:0% and the universe was filled with it. 00:28:31.400 --> 00:28:33.990 align:start position:0% and the universe was filled with it. Light<00:28:31.840> gets<00:28:32.080> trapped<00:28:32.400> in<00:28:32.520> plasma,<00:28:33.440> unable<00:28:33.880> to 00:28:33.990 --> 00:28:34.000 align:start position:0% Light gets trapped in plasma, unable to 00:28:34.000 --> 00:28:36.310 align:start position:0% Light gets trapped in plasma, unable to move<00:28:34.320> through<00:28:34.600> space<00:28:35.200> without<00:28:35.600> bumping<00:28:36.000> into 00:28:36.310 --> 00:28:36.320 align:start position:0% move through space without bumping into 00:28:36.320 --> 00:28:38.910 align:start position:0% move through space without bumping into the<00:28:36.440> charged<00:28:36.840> electrons<00:28:37.440> and<00:28:37.520> protons,<00:28:38.680> being 00:28:38.910 --> 00:28:38.920 align:start position:0% the charged electrons and protons, being 00:28:38.920 --> 00:28:42.470 align:start position:0% the charged electrons and protons, being continuously<00:28:39.880> absorbed<00:28:40.720> and<00:28:40.840> emitted. 00:28:42.470 --> 00:28:42.480 align:start position:0% continuously absorbed and emitted. 00:28:42.480 --> 00:28:44.350 align:start position:0% continuously absorbed and emitted. But,<00:28:42.680> once<00:28:42.960> the<00:28:43.040> universe<00:28:43.400> expanded<00:28:44.240> and 00:28:44.350 --> 00:28:44.360 align:start position:0% But, once the universe expanded and 00:28:44.360 --> 00:28:46.230 align:start position:0% But, once the universe expanded and cooled<00:28:44.640> down<00:28:44.920> enough<00:28:45.240> for<00:28:45.360> the<00:28:45.480> protons<00:28:46.120> and 00:28:46.230 --> 00:28:46.240 align:start position:0% cooled down enough for the protons and 00:28:46.240 --> 00:28:48.510 align:start position:0% cooled down enough for the protons and electrons<00:28:46.880> to<00:28:47.000> coalesce<00:28:47.800> into<00:28:48.040> neutral 00:28:48.510 --> 00:28:48.520 align:start position:0% electrons to coalesce into neutral 00:28:48.520 --> 00:28:51.110 align:start position:0% electrons to coalesce into neutral hydrogen<00:28:49.080> and<00:28:49.160> helium<00:28:49.600> atoms,<00:28:50.480> it<00:28:50.640> suddenly 00:28:51.110 --> 00:28:51.120 align:start position:0% hydrogen and helium atoms, it suddenly 00:28:51.120 --> 00:28:53.630 align:start position:0% hydrogen and helium atoms, it suddenly became<00:28:51.560> transparent.<00:28:52.960> The<00:28:53.080> light<00:28:53.440> was 00:28:53.630 --> 00:28:53.640 align:start position:0% became transparent. The light was 00:28:53.640 --> 00:28:55.910 align:start position:0% became transparent. The light was finally<00:28:54.160> freed. 00:28:55.910 --> 00:28:55.920 align:start position:0% finally freed. 00:28:55.920 --> 00:28:57.950 align:start position:0% finally freed. This<00:28:56.120> light<00:28:56.480> was<00:28:56.600> then<00:28:56.800> stretched<00:28:57.680> by<00:28:57.840> the 00:28:57.950 --> 00:28:57.960 align:start position:0% This light was then stretched by the 00:28:57.960 --> 00:28:59.910 align:start position:0% This light was then stretched by the expansion<00:28:58.440> of<00:28:58.520> the<00:28:58.600> universe<00:28:59.440> until<00:28:59.720> it 00:28:59.910 --> 00:28:59.920 align:start position:0% expansion of the universe until it 00:28:59.920 --> 00:29:02.790 align:start position:0% expansion of the universe until it redshifted<00:29:00.600> into<00:29:00.880> microwave<00:29:01.520> light. 00:29:02.790 --> 00:29:02.800 align:start position:0% redshifted into microwave light. 00:29:02.800 --> 00:29:04.630 align:start position:0% redshifted into microwave light. This<00:29:02.960> is<00:29:03.120> why<00:29:03.440> the<00:29:03.600> cosmic<00:29:04.120> microwave 00:29:04.630 --> 00:29:04.640 align:start position:0% This is why the cosmic microwave 00:29:04.640 --> 00:29:07.230 align:start position:0% This is why the cosmic microwave background<00:29:05.400> is<00:29:05.560> the<00:29:05.840> earliest<00:29:06.360> light<00:29:07.000> of<00:29:07.120> the 00:29:07.230 --> 00:29:07.240 align:start position:0% background is the earliest light of the 00:29:07.240 --> 00:29:08.750 align:start position:0% background is the earliest light of the universe. 00:29:08.750 --> 00:29:08.760 align:start position:0% universe. 00:29:08.760 --> 00:29:11.310 align:start position:0% universe. But<00:29:09.040> gravitational<00:29:10.040> waves<00:29:10.600> are<00:29:10.720> not<00:29:11.000> made<00:29:11.200> of 00:29:11.310 --> 00:29:11.320 align:start position:0% But gravitational waves are not made of 00:29:11.320 --> 00:29:12.270 align:start position:0% But gravitational waves are not made of light. 00:29:12.270 --> 00:29:12.280 align:start position:0% light. 00:29:12.280 --> 00:29:15.790 align:start position:0% light. They<00:29:12.440> are<00:29:12.520> made<00:29:12.880> of<00:29:13.080> space-time<00:29:14.000> itself. 00:29:15.790 --> 00:29:15.800 align:start position:0% They are made of space-time itself. 00:29:15.800 --> 00:29:18.390 align:start position:0% They are made of space-time itself. Plasma<00:29:16.400> is<00:29:16.680> no<00:29:16.960> obstacle<00:29:17.440> to<00:29:17.560> them. 00:29:18.390 --> 00:29:18.400 align:start position:0% Plasma is no obstacle to them. 00:29:18.400 --> 00:29:20.590 align:start position:0% Plasma is no obstacle to them. To<00:29:18.480> gravitational<00:29:19.200> waves,<00:29:19.880> the<00:29:20.000> universe<00:29:20.440> has 00:29:20.590 --> 00:29:20.600 align:start position:0% To gravitational waves, the universe has 00:29:20.600 --> 00:29:23.190 align:start position:0% To gravitational waves, the universe has been<00:29:20.760> transparent<00:29:21.720> from<00:29:22.040> almost<00:29:22.480> the<00:29:22.600> very 00:29:23.190 --> 00:29:23.200 align:start position:0% been transparent from almost the very 00:29:23.200 --> 00:29:26.190 align:start position:0% been transparent from almost the very instant<00:29:23.800> of<00:29:23.920> the<00:29:24.000> Big<00:29:24.200> Bang<00:29:24.520> itself. 00:29:26.190 --> 00:29:26.200 align:start position:0% instant of the Big Bang itself. 00:29:26.200 --> 00:29:28.110 align:start position:0% instant of the Big Bang itself. They<00:29:26.360> can<00:29:26.520> penetrate<00:29:27.040> past<00:29:27.520> this<00:29:27.680> plasma 00:29:28.110 --> 00:29:28.120 align:start position:0% They can penetrate past this plasma 00:29:28.120 --> 00:29:30.430 align:start position:0% They can penetrate past this plasma barrier<00:29:28.920> and<00:29:29.120> offer<00:29:29.360> us<00:29:29.600> a<00:29:29.680> glimpse<00:29:30.240> of<00:29:30.320> the 00:29:30.430 --> 00:29:30.440 align:start position:0% barrier and offer us a glimpse of the 00:29:30.440 --> 00:29:32.230 align:start position:0% barrier and offer us a glimpse of the very<00:29:30.800> first<00:29:31.080> moments<00:29:31.520> of<00:29:31.600> the<00:29:31.680> universe's 00:29:32.230 --> 00:29:32.240 align:start position:0% very first moments of the universe's 00:29:32.240 --> 00:29:33.990 align:start position:0% very first moments of the universe's creation. 00:29:33.990 --> 00:29:34.000 align:start position:0% creation. 00:29:34.000 --> 00:29:35.950 align:start position:0% creation. Because<00:29:34.400> these<00:29:34.640> primordial<00:29:35.320> gravitational 00:29:35.950 --> 00:29:35.960 align:start position:0% Because these primordial gravitational 00:29:35.960 --> 00:29:38.030 align:start position:0% Because these primordial gravitational waves<00:29:36.320> have<00:29:36.440> been<00:29:36.560> traveling<00:29:37.040> for<00:29:37.120> so<00:29:37.320> long, 00:29:38.030 --> 00:29:38.040 align:start position:0% waves have been traveling for so long, 00:29:38.040 --> 00:29:39.870 align:start position:0% waves have been traveling for so long, even<00:29:38.320> if<00:29:38.440> they<00:29:38.640> were<00:29:39.000> originally<00:29:39.440> produced 00:29:39.870 --> 00:29:39.880 align:start position:0% even if they were originally produced 00:29:39.880 --> 00:29:41.910 align:start position:0% even if they were originally produced with<00:29:40.000> a<00:29:40.080> high<00:29:40.240> frequency,<00:29:41.240> they<00:29:41.400> would<00:29:41.600> be 00:29:41.910 --> 00:29:41.920 align:start position:0% with a high frequency, they would be 00:29:41.920 --> 00:29:43.750 align:start position:0% with a high frequency, they would be greatly<00:29:42.440> stretched<00:29:42.880> by<00:29:43.000> the<00:29:43.120> expansion<00:29:43.640> of 00:29:43.750 --> 00:29:43.760 align:start position:0% greatly stretched by the expansion of 00:29:43.760 --> 00:29:45.430 align:start position:0% greatly stretched by the expansion of space-time. 00:29:45.430 --> 00:29:45.440 align:start position:0% space-time. 00:29:45.440 --> 00:29:47.830 align:start position:0% space-time. They<00:29:45.520> would<00:29:45.680> be<00:29:45.800> redshifted<00:29:46.680> into<00:29:47.000> ultra-low 00:29:47.830 --> 00:29:47.840 align:start position:0% They would be redshifted into ultra-low 00:29:47.840 --> 00:29:50.310 align:start position:0% They would be redshifted into ultra-low frequency<00:29:48.400> gravitational<00:29:49.080> waves,<00:29:49.840> the<00:29:49.960> same 00:29:50.310 --> 00:29:50.320 align:start position:0% frequency gravitational waves, the same 00:29:50.320 --> 00:29:52.150 align:start position:0% frequency gravitational waves, the same kind<00:29:50.720> that<00:29:50.840> would<00:29:51.000> come<00:29:51.320> from<00:29:51.560> black<00:29:51.920> hole 00:29:52.150 --> 00:29:52.160 align:start position:0% kind that would come from black hole 00:29:52.160 --> 00:29:54.950 align:start position:0% kind that would come from black hole binaries. 00:29:54.950 --> 00:29:54.960 align:start position:0% 00:29:54.960 --> 00:29:57.470 align:start position:0% Together,<00:29:55.760> these<00:29:56.120> multiple<00:29:56.720> sources<00:29:57.360> will 00:29:57.470 --> 00:29:57.480 align:start position:0% Together, these multiple sources will 00:29:57.480 --> 00:30:00.030 align:start position:0% Together, these multiple sources will give<00:29:57.680> us<00:29:57.840> a<00:29:57.880> so-called<00:29:58.800> stochastic 00:30:00.030 --> 00:30:00.040 align:start position:0% give us a so-called stochastic 00:30:00.040 --> 00:30:02.870 align:start position:0% give us a so-called stochastic gravitational<00:30:00.840> wave<00:30:01.360> background<00:30:02.200> existing 00:30:02.870 --> 00:30:02.880 align:start position:0% gravitational wave background existing 00:30:02.880 --> 00:30:06.150 align:start position:0% gravitational wave background existing over<00:30:03.200> a<00:30:03.320> range<00:30:03.840> of<00:30:04.000> low<00:30:04.160> frequencies. 00:30:06.150 --> 00:30:06.160 align:start position:0% over a range of low frequencies. 00:30:06.160 --> 00:30:07.830 align:start position:0% over a range of low frequencies. How<00:30:06.360> can<00:30:06.520> astronomers<00:30:07.000> retrieve<00:30:07.600> this 00:30:07.830 --> 00:30:07.840 align:start position:0% How can astronomers retrieve this 00:30:07.840 --> 00:30:09.470 align:start position:0% How can astronomers retrieve this treasure<00:30:08.200> trove<00:30:08.520> of<00:30:08.640> information<00:30:09.160> about 00:30:09.470 --> 00:30:09.480 align:start position:0% treasure trove of information about 00:30:09.480 --> 00:30:12.230 align:start position:0% treasure trove of information about black<00:30:09.800> holes,<00:30:10.280> the<00:30:10.400> Big<00:30:10.600> Bang,<00:30:11.040> and<00:30:11.200> more? 00:30:12.230 --> 00:30:12.240 align:start position:0% black holes, the Big Bang, and more? 00:30:12.240 --> 00:30:14.710 align:start position:0% black holes, the Big Bang, and more? Can<00:30:12.400> we<00:30:12.560> build<00:30:13.000> a<00:30:13.080> better<00:30:13.520> LIGO<00:30:14.160> and<00:30:14.280> detect 00:30:14.710 --> 00:30:14.720 align:start position:0% Can we build a better LIGO and detect 00:30:14.720 --> 00:30:16.790 align:start position:0% Can we build a better LIGO and detect how<00:30:14.840> the<00:30:15.080> Earth<00:30:15.280> is<00:30:15.520> bobbing<00:30:16.040> up<00:30:16.200> and<00:30:16.320> down<00:30:16.720> in 00:30:16.790 --> 00:30:16.800 align:start position:0% how the Earth is bobbing up and down in 00:30:16.800 --> 00:30:19.990 align:start position:0% how the Earth is bobbing up and down in these<00:30:17.000> gargantuan<00:30:17.880> gravitational<00:30:18.560> waves? 00:30:19.990 --> 00:30:20.000 align:start position:0% these gargantuan gravitational waves? 00:30:20.000 --> 00:30:20.870 align:start position:0% these gargantuan gravitational waves? Well, 00:30:20.870 --> 00:30:20.880 align:start position:0% Well, 00:30:20.880 --> 00:30:23.310 align:start position:0% Well, LIGO<00:30:21.200> works<00:30:21.600> by<00:30:21.760> sending<00:30:22.160> two<00:30:22.520> beams<00:30:22.840> of<00:30:22.960> light 00:30:23.310 --> 00:30:23.320 align:start position:0% LIGO works by sending two beams of light 00:30:23.320 --> 00:30:25.550 align:start position:0% LIGO works by sending two beams of light being<00:30:23.560> sent<00:30:23.840> along<00:30:24.160> perpendicular<00:30:25.120> tunnel 00:30:25.550 --> 00:30:25.560 align:start position:0% being sent along perpendicular tunnel 00:30:25.560 --> 00:30:26.750 align:start position:0% being sent along perpendicular tunnel arms. 00:30:26.750 --> 00:30:26.760 align:start position:0% arms. 00:30:26.760 --> 00:30:28.590 align:start position:0% arms. The<00:30:26.840> beams<00:30:27.240> are<00:30:27.360> reflected<00:30:27.960> by<00:30:28.160> mirrors<00:30:28.520> at 00:30:28.590 --> 00:30:28.600 align:start position:0% The beams are reflected by mirrors at 00:30:28.600 --> 00:30:30.510 align:start position:0% The beams are reflected by mirrors at the<00:30:28.720> ends<00:30:29.000> of<00:30:29.120> each<00:30:29.280> of<00:30:29.360> those<00:30:29.560> tunnels<00:30:30.400> and 00:30:30.510 --> 00:30:30.520 align:start position:0% the ends of each of those tunnels and 00:30:30.520 --> 00:30:32.550 align:start position:0% the ends of each of those tunnels and they<00:30:30.640> return<00:30:31.160> to<00:30:31.240> the<00:30:31.320> starting<00:30:31.760> point<00:30:32.400> and 00:30:32.550 --> 00:30:32.560 align:start position:0% they return to the starting point and 00:30:32.560 --> 00:30:35.150 align:start position:0% they return to the starting point and are<00:30:32.640> compared<00:30:33.040> with<00:30:33.160> each<00:30:33.360> other. 00:30:35.150 --> 00:30:35.160 align:start position:0% are compared with each other. 00:30:35.160 --> 00:30:37.270 align:start position:0% are compared with each other. This<00:30:35.320> is<00:30:35.480> so<00:30:35.960> that<00:30:36.240> if<00:30:36.440> space-time<00:30:37.040> gets 00:30:37.270 --> 00:30:37.280 align:start position:0% This is so that if space-time gets 00:30:37.280 --> 00:30:39.550 align:start position:0% This is so that if space-time gets distorted<00:30:37.920> along<00:30:38.280> one<00:30:38.440> direction,<00:30:39.480> the 00:30:39.550 --> 00:30:39.560 align:start position:0% distorted along one direction, the 00:30:39.560 --> 00:30:41.630 align:start position:0% distorted along one direction, the information<00:30:40.080> from<00:30:40.240> the<00:30:40.560> other<00:30:40.840> direction<00:30:41.440> can 00:30:41.630 --> 00:30:41.640 align:start position:0% information from the other direction can 00:30:41.640 --> 00:30:43.390 align:start position:0% information from the other direction can be<00:30:41.760> used<00:30:42.080> to<00:30:42.200> get<00:30:42.360> a<00:30:42.400> sense<00:30:42.720> of<00:30:42.840> how<00:30:43.080> much<00:30:43.320> it 00:30:43.390 --> 00:30:43.400 align:start position:0% be used to get a sense of how much it 00:30:43.400 --> 00:30:44.990 align:start position:0% be used to get a sense of how much it has<00:30:43.560> changed. 00:30:44.990 --> 00:30:45.000 align:start position:0% has changed. 00:30:45.000 --> 00:30:47.190 align:start position:0% has changed. Unfortunately,<00:30:46.000> if<00:30:46.160> we<00:30:46.320> were<00:30:46.600> to<00:30:46.680> design<00:30:47.120> a 00:30:47.190 --> 00:30:47.200 align:start position:0% Unfortunately, if we were to design a 00:30:47.200 --> 00:30:49.190 align:start position:0% Unfortunately, if we were to design a new<00:30:47.480> LIGO<00:30:47.880> to<00:30:48.000> detect<00:30:48.400> these<00:30:48.600> gravitational 00:30:49.190 --> 00:30:49.200 align:start position:0% new LIGO to detect these gravitational 00:30:49.200 --> 00:30:51.630 align:start position:0% new LIGO to detect these gravitational waves,<00:30:50.000> we<00:30:50.160> would<00:30:50.360> need<00:30:50.600> to<00:30:50.720> have<00:30:51.000> tunnel<00:30:51.360> arms 00:30:51.630 --> 00:30:51.640 align:start position:0% waves, we would need to have tunnel arms 00:30:51.640 --> 00:30:53.910 align:start position:0% waves, we would need to have tunnel arms that<00:30:51.840> are<00:30:51.960> much<00:30:52.720> larger<00:30:53.080> than<00:30:53.320> anything<00:30:53.800> we 00:30:53.910 --> 00:30:53.920 align:start position:0% that are much larger than anything we 00:30:53.920 --> 00:30:55.670 align:start position:0% that are much larger than anything we could<00:30:54.040> build<00:30:54.320> on<00:30:54.480> Earth. 00:30:55.670 --> 00:30:55.680 align:start position:0% could build on Earth. 00:30:55.680 --> 00:30:57.710 align:start position:0% could build on Earth. This<00:30:55.760> is<00:30:55.880> because<00:30:56.280> the<00:30:56.440> frequency<00:30:57.040> of<00:30:57.200> a<00:30:57.240> wave 00:30:57.710 --> 00:30:57.720 align:start position:0% This is because the frequency of a wave 00:30:57.720 --> 00:30:59.430 align:start position:0% This is because the frequency of a wave is<00:30:57.880> inversely<00:30:58.560> proportional<00:30:59.160> to<00:30:59.280> its 00:30:59.430 --> 00:30:59.440 align:start position:0% is inversely proportional to its 00:30:59.440 --> 00:31:00.910 align:start position:0% is inversely proportional to its wavelength. 00:31:00.910 --> 00:31:00.920 align:start position:0% wavelength. 00:31:00.920 --> 00:31:03.150 align:start position:0% wavelength. Ultra-low<00:31:01.640> frequency<00:31:02.120> waves<00:31:02.800> have<00:31:02.960> an 00:31:03.150 --> 00:31:03.160 align:start position:0% Ultra-low frequency waves have an 00:31:03.160 --> 00:31:05.710 align:start position:0% Ultra-low frequency waves have an ultra-long<00:31:03.840> wavelength<00:31:04.720> and<00:31:04.920> would<00:31:05.120> require 00:31:05.710 --> 00:31:05.720 align:start position:0% ultra-long wavelength and would require 00:31:05.720 --> 00:31:07.910 align:start position:0% ultra-long wavelength and would require us<00:31:05.920> to<00:31:06.080> look<00:31:06.360> at<00:31:06.480> changes<00:31:06.960> over<00:31:07.240> a<00:31:07.320> much 00:31:07.910 --> 00:31:07.920 align:start position:0% us to look at changes over a much 00:31:07.920 --> 00:31:09.990 align:start position:0% us to look at changes over a much greater<00:31:08.320> distance<00:31:08.920> to<00:31:09.040> notice<00:31:09.400> the<00:31:09.520> effects 00:31:09.990 --> 00:31:10.000 align:start position:0% greater distance to notice the effects 00:31:10.000 --> 00:31:12.070 align:start position:0% greater distance to notice the effects of<00:31:10.080> these<00:31:10.200> gravitational<00:31:10.840> waves. 00:31:12.070 --> 00:31:12.080 align:start position:0% of these gravitational waves. 00:31:12.080 --> 00:31:15.270 align:start position:0% of these gravitational waves. For<00:31:12.480> nanohertz<00:31:13.280> waves,<00:31:14.040> that<00:31:14.200> is<00:31:14.680> one<00:31:15.040> full 00:31:15.270 --> 00:31:15.280 align:start position:0% For nanohertz waves, that is one full 00:31:15.280 --> 00:31:18.550 align:start position:0% For nanohertz waves, that is one full fluctuation<00:31:16.240> taking<00:31:16.720> a<00:31:16.840> billion<00:31:17.520> seconds,<00:31:18.480> a 00:31:18.550 --> 00:31:18.560 align:start position:0% fluctuation taking a billion seconds, a 00:31:18.560 --> 00:31:20.310 align:start position:0% fluctuation taking a billion seconds, a quick<00:31:18.880> calculation 00:31:20.310 --> 00:31:20.320 align:start position:0% quick calculation 00:31:20.320 --> 00:31:22.230 align:start position:0% quick calculation wavelength<00:31:20.840> equals<00:31:21.200> speed<00:31:21.560> of<00:31:21.680> wave<00:31:22.040> over 00:31:22.230 --> 00:31:22.240 align:start position:0% wavelength equals speed of wave over 00:31:22.240 --> 00:31:23.510 align:start position:0% wavelength equals speed of wave over frequency 00:31:23.510 --> 00:31:23.520 align:start position:0% frequency 00:31:23.520 --> 00:31:25.830 align:start position:0% frequency tells<00:31:23.840> us<00:31:24.040> that<00:31:24.400> the<00:31:24.640> wavelength<00:31:25.240> would<00:31:25.400> be 00:31:25.830 --> 00:31:25.840 align:start position:0% tells us that the wavelength would be 00:31:25.840 --> 00:31:30.150 align:start position:0% tells us that the wavelength would be around<00:31:26.360> 10<00:31:26.880> to<00:31:27.000> the<00:31:27.080> power<00:31:27.400> 17<00:31:28.520> m. 00:31:30.150 --> 00:31:30.160 align:start position:0% around 10 to the power 17 m. 00:31:30.160 --> 00:31:32.230 align:start position:0% around 10 to the power 17 m. For<00:31:30.240> a<00:31:30.320> sense<00:31:30.560> of<00:31:30.680> scale,<00:31:31.680> the<00:31:31.760> distance 00:31:32.230 --> 00:31:32.240 align:start position:0% For a sense of scale, the distance 00:31:32.240 --> 00:31:34.550 align:start position:0% For a sense of scale, the distance between<00:31:32.640> the<00:31:32.800> Earth<00:31:33.160> and<00:31:33.280> the<00:31:33.360> Sun,<00:31:34.200> or<00:31:34.360> an 00:31:34.550 --> 00:31:34.560 align:start position:0% between the Earth and the Sun, or an 00:31:34.560 --> 00:31:37.590 align:start position:0% between the Earth and the Sun, or an astronomical<00:31:35.280> unit,<00:31:35.960> is<00:31:36.160> 10<00:31:36.400> to<00:31:36.480> the<00:31:36.600> power<00:31:37.040> 11 00:31:37.590 --> 00:31:37.600 align:start position:0% astronomical unit, is 10 to the power 11 00:31:37.600 --> 00:31:38.990 align:start position:0% astronomical unit, is 10 to the power 11 m. 00:31:38.990 --> 00:31:39.000 align:start position:0% m. 00:31:39.000 --> 00:31:41.750 align:start position:0% m. A<00:31:39.080> light-year<00:31:40.520> is<00:31:40.680> around<00:31:41.040> 10<00:31:41.320> to<00:31:41.440> the<00:31:41.520> power 00:31:41.750 --> 00:31:41.760 align:start position:0% A light-year is around 10 to the power 00:31:41.760 --> 00:31:43.790 align:start position:0% A light-year is around 10 to the power 16<00:31:42.360> m. 00:31:43.790 --> 00:31:43.800 align:start position:0% 16 m. 00:31:43.800 --> 00:31:45.990 align:start position:0% 16 m. The<00:31:43.880> wavelengths<00:31:44.480> we<00:31:44.640> are<00:31:44.720> discussing<00:31:45.800> are 00:31:45.990 --> 00:31:46.000 align:start position:0% The wavelengths we are discussing are 00:31:46.000 --> 00:31:49.230 align:start position:0% The wavelengths we are discussing are tens<00:31:46.720> of<00:31:46.960> light-years<00:31:47.600> long. 00:31:49.230 --> 00:31:49.240 align:start position:0% tens of light-years long. 00:31:49.240 --> 00:31:51.230 align:start position:0% tens of light-years long. Clearly,<00:31:49.960> we<00:31:50.080> cannot<00:31:50.440> build<00:31:50.840> anything 00:31:51.230 --> 00:31:51.240 align:start position:0% Clearly, we cannot build anything 00:31:51.240 --> 00:31:53.670 align:start position:0% Clearly, we cannot build anything suitable<00:31:51.760> for<00:31:51.840> this<00:31:52.000> task<00:31:52.320> on<00:31:52.520> Earth<00:31:53.080> or<00:31:53.360> even 00:31:53.670 --> 00:31:53.680 align:start position:0% suitable for this task on Earth or even 00:31:53.680 --> 00:31:55.190 align:start position:0% suitable for this task on Earth or even in<00:31:53.760> the<00:31:53.840> solar<00:31:54.120> system. 00:31:55.190 --> 00:31:55.200 align:start position:0% in the solar system. 00:31:55.200 --> 00:31:56.950 align:start position:0% in the solar system. We<00:31:55.240> need<00:31:55.400> to<00:31:55.480> go<00:31:55.760> beyond<00:31:56.440> our<00:31:56.640> stellar 00:31:56.950 --> 00:31:56.960 align:start position:0% We need to go beyond our stellar 00:31:56.960 --> 00:31:58.470 align:start position:0% We need to go beyond our stellar neighborhood. 00:31:58.470 --> 00:31:58.480 align:start position:0% neighborhood. 00:31:58.480 --> 00:32:00.550 align:start position:0% neighborhood. But<00:31:58.880> rather<00:31:59.240> than<00:31:59.480> wait<00:31:59.800> for<00:31:59.920> humanity<00:32:00.440> to 00:32:00.550 --> 00:32:00.560 align:start position:0% But rather than wait for humanity to 00:32:00.560 --> 00:32:02.790 align:start position:0% But rather than wait for humanity to ascend<00:32:01.160> beyond<00:32:01.480> the<00:32:01.560> confines<00:32:02.200> of<00:32:02.320> our<00:32:02.480> solar 00:32:02.790 --> 00:32:02.800 align:start position:0% ascend beyond the confines of our solar 00:32:02.800 --> 00:32:04.710 align:start position:0% ascend beyond the confines of our solar system<00:32:03.560> and<00:32:03.680> become<00:32:04.040> a<00:32:04.120> space-faring 00:32:04.710 --> 00:32:04.720 align:start position:0% system and become a space-faring 00:32:04.720 --> 00:32:07.870 align:start position:0% system and become a space-faring civilization,<00:32:06.040> astronomers<00:32:06.720> at<00:32:06.920> NANOGrav 00:32:07.870 --> 00:32:07.880 align:start position:0% civilization, astronomers at NANOGrav 00:32:07.880 --> 00:32:11.110 align:start position:0% civilization, astronomers at NANOGrav have<00:32:08.040> used<00:32:08.400> a<00:32:08.440> clever<00:32:08.880> trick. 00:32:11.110 --> 00:32:11.120 align:start position:0% have used a clever trick. 00:32:11.120 --> 00:32:13.190 align:start position:0% have used a clever trick. You<00:32:11.200> may<00:32:11.400> recall<00:32:12.080> our<00:32:12.320> recent<00:32:12.680> episode<00:32:13.080> on 00:32:13.190 --> 00:32:13.200 align:start position:0% You may recall our recent episode on 00:32:13.200 --> 00:32:15.430 align:start position:0% You may recall our recent episode on pulsars<00:32:14.120> and<00:32:14.240> how<00:32:14.360> we<00:32:14.480> discussed<00:32:15.000> that<00:32:15.120> these 00:32:15.430 --> 00:32:15.440 align:start position:0% pulsars and how we discussed that these 00:32:15.440 --> 00:32:17.790 align:start position:0% pulsars and how we discussed that these ultra-dense<00:32:16.240> neutron<00:32:16.600> stars<00:32:17.200> are<00:32:17.400> able<00:32:17.680> to 00:32:17.790 --> 00:32:17.800 align:start position:0% ultra-dense neutron stars are able to 00:32:17.800 --> 00:32:20.670 align:start position:0% ultra-dense neutron stars are able to spin<00:32:18.200> with<00:32:18.520> remarkable<00:32:19.160> stability. 00:32:20.670 --> 00:32:20.680 align:start position:0% spin with remarkable stability. 00:32:20.680 --> 00:32:22.950 align:start position:0% spin with remarkable stability. They<00:32:20.800> emit<00:32:21.080> light<00:32:21.480> along<00:32:21.760> their<00:32:21.920> poles<00:32:22.720> and<00:32:22.840> we 00:32:22.950 --> 00:32:22.960 align:start position:0% They emit light along their poles and we 00:32:22.960 --> 00:32:25.190 align:start position:0% They emit light along their poles and we can<00:32:23.080> detect<00:32:23.520> the<00:32:23.600> pulses<00:32:24.160> that<00:32:24.320> we<00:32:24.440> receive<00:32:25.000> as 00:32:25.190 --> 00:32:25.200 align:start position:0% can detect the pulses that we receive as 00:32:25.200 --> 00:32:27.190 align:start position:0% can detect the pulses that we receive as those<00:32:25.440> of<00:32:25.520> vast<00:32:26.000> beams<00:32:26.320> of<00:32:26.440> light<00:32:26.840> swoop 00:32:27.190 --> 00:32:27.200 align:start position:0% those of vast beams of light swoop 00:32:27.200 --> 00:32:29.470 align:start position:0% those of vast beams of light swoop around<00:32:27.840> and<00:32:27.960> hit<00:32:28.120> the<00:32:28.320> Earth<00:32:28.680> again<00:32:29.360> and 00:32:29.470 --> 00:32:29.480 align:start position:0% around and hit the Earth again and 00:32:29.480 --> 00:32:31.030 align:start position:0% around and hit the Earth again and again. 00:32:31.030 --> 00:32:31.040 align:start position:0% again. 00:32:31.040 --> 00:32:32.950 align:start position:0% again. These<00:32:31.200> pulses<00:32:31.600> come<00:32:31.880> with<00:32:32.000> such<00:32:32.280> precise 00:32:32.950 --> 00:32:32.960 align:start position:0% These pulses come with such precise 00:32:32.960 --> 00:32:35.390 align:start position:0% These pulses come with such precise certainty<00:32:33.840> that<00:32:34.000> they<00:32:34.160> are<00:32:34.320> used<00:32:34.720> as<00:32:34.880> clocks 00:32:35.390 --> 00:32:35.400 align:start position:0% certainty that they are used as clocks 00:32:35.400 --> 00:32:38.190 align:start position:0% certainty that they are used as clocks of<00:32:35.520> the<00:32:35.640> cosmos,<00:32:36.760> able<00:32:37.040> to<00:32:37.120> keep<00:32:37.400> time<00:32:37.800> across 00:32:38.190 --> 00:32:38.200 align:start position:0% of the cosmos, able to keep time across 00:32:38.200 --> 00:32:40.270 align:start position:0% of the cosmos, able to keep time across vast<00:32:38.640> distances. 00:32:40.270 --> 00:32:40.280 align:start position:0% vast distances. 00:32:40.280 --> 00:32:42.990 align:start position:0% vast distances. Therefore,<00:32:41.160> we<00:32:41.280> can<00:32:41.480> use<00:32:41.880> already<00:32:42.280> identified 00:32:42.990 --> 00:32:43.000 align:start position:0% Therefore, we can use already identified 00:32:43.000 --> 00:32:44.950 align:start position:0% Therefore, we can use already identified pulsars<00:32:43.560> to<00:32:43.680> supply<00:32:44.040> us<00:32:44.240> with<00:32:44.480> reliable 00:32:44.950 --> 00:32:44.960 align:start position:0% pulsars to supply us with reliable 00:32:44.960 --> 00:32:46.830 align:start position:0% pulsars to supply us with reliable signals<00:32:45.440> from<00:32:45.640> thousands<00:32:46.320> of<00:32:46.440> light-years 00:32:46.830 --> 00:32:46.840 align:start position:0% signals from thousands of light-years 00:32:46.840 --> 00:32:48.510 align:start position:0% signals from thousands of light-years away. 00:32:48.510 --> 00:32:48.520 align:start position:0% away. 00:32:48.520 --> 00:32:50.630 align:start position:0% away. The<00:32:48.640> pulsars<00:32:49.360> are<00:32:49.480> like<00:32:49.720> the<00:32:49.840> mirrors<00:32:50.400> at<00:32:50.520> the 00:32:50.630 --> 00:32:50.640 align:start position:0% The pulsars are like the mirrors at the 00:32:50.640 --> 00:32:52.950 align:start position:0% The pulsars are like the mirrors at the end<00:32:50.840> of<00:32:50.920> the<00:32:51.040> LIGO<00:32:51.520> arms,<00:32:52.360> but<00:32:52.520> rather<00:32:52.800> than 00:32:52.950 --> 00:32:52.960 align:start position:0% end of the LIGO arms, but rather than 00:32:52.960 --> 00:32:55.550 align:start position:0% end of the LIGO arms, but rather than sending<00:32:53.320> us<00:32:53.440> back<00:32:53.760> a<00:32:53.840> signal<00:32:54.280> we<00:32:54.440> sent<00:32:54.640> across, 00:32:55.550 --> 00:32:55.560 align:start position:0% sending us back a signal we sent across, 00:32:55.560 --> 00:32:58.270 align:start position:0% sending us back a signal we sent across, they<00:32:55.800> are<00:32:55.960> generating<00:32:56.600> their<00:32:56.880> own. 00:32:58.270 --> 00:32:58.280 align:start position:0% they are generating their own. 00:32:58.280 --> 00:33:01.030 align:start position:0% they are generating their own. NANOGrav<00:32:59.040> have<00:32:59.440> cleverly<00:33:00.200> concocted<00:33:00.920> an 00:33:01.030 --> 00:33:01.040 align:start position:0% NANOGrav have cleverly concocted an 00:33:01.040 --> 00:33:03.630 align:start position:0% NANOGrav have cleverly concocted an imaginary<00:33:01.840> interferometer<00:33:02.960> that<00:33:03.080> stretches 00:33:03.630 --> 00:33:03.640 align:start position:0% imaginary interferometer that stretches 00:33:03.640 --> 00:33:06.510 align:start position:0% imaginary interferometer that stretches for<00:33:03.800> thousands<00:33:04.480> of<00:33:04.640> light-years,<00:33:05.800> and<00:33:06.120> all<00:33:06.400> we 00:33:06.510 --> 00:33:06.520 align:start position:0% for thousands of light-years, and all we 00:33:06.520 --> 00:33:09.270 align:start position:0% for thousands of light-years, and all we need<00:33:06.880> to<00:33:07.000> use<00:33:07.240> it<00:33:07.760> are<00:33:07.880> the<00:33:08.040> good<00:33:08.560> old<00:33:08.960> radio 00:33:09.270 --> 00:33:09.280 align:start position:0% need to use it are the good old radio 00:33:09.280 --> 00:33:11.110 align:start position:0% need to use it are the good old radio telescopes<00:33:10.160> that<00:33:10.280> we've<00:33:10.480> been<00:33:10.680> using<00:33:11.000> for 00:33:11.110 --> 00:33:11.120 align:start position:0% telescopes that we've been using for 00:33:11.120 --> 00:33:12.630 align:start position:0% telescopes that we've been using for decades. 00:33:12.630 --> 00:33:12.640 align:start position:0% decades. 00:33:12.640 --> 00:33:14.990 align:start position:0% decades. But,<00:33:13.040> our<00:33:13.240> calculations<00:33:14.200> will<00:33:14.480> only<00:33:14.760> be<00:33:14.880> as 00:33:14.990 --> 00:33:15.000 align:start position:0% But, our calculations will only be as 00:33:15.000 --> 00:33:17.190 align:start position:0% But, our calculations will only be as good<00:33:15.280> as<00:33:15.400> our<00:33:15.600> observations. 00:33:17.190 --> 00:33:17.200 align:start position:0% good as our observations. 00:33:17.200 --> 00:33:19.390 align:start position:0% good as our observations. When<00:33:17.440> choosing<00:33:17.880> pulsars<00:33:18.480> to<00:33:18.560> observe,<00:33:19.320> we 00:33:19.390 --> 00:33:19.400 align:start position:0% When choosing pulsars to observe, we 00:33:19.400 --> 00:33:21.150 align:start position:0% When choosing pulsars to observe, we need<00:33:19.560> to<00:33:19.640> make<00:33:19.840> sure<00:33:20.040> that<00:33:20.200> they<00:33:20.400> are<00:33:20.560> suitable 00:33:21.150 --> 00:33:21.160 align:start position:0% need to make sure that they are suitable 00:33:21.160 --> 00:33:22.670 align:start position:0% need to make sure that they are suitable for<00:33:21.280> the<00:33:21.400> task. 00:33:22.670 --> 00:33:22.680 align:start position:0% for the task. 00:33:22.680 --> 00:33:25.430 align:start position:0% for the task. The<00:33:22.840> best<00:33:23.120> candidates<00:33:23.960> are<00:33:24.160> hand-picked<00:33:25.200> and 00:33:25.430 --> 00:33:25.440 align:start position:0% The best candidates are hand-picked and 00:33:25.440 --> 00:33:28.230 align:start position:0% The best candidates are hand-picked and added<00:33:25.720> to<00:33:25.840> a<00:33:25.920> group<00:33:26.280> called<00:33:26.840> a<00:33:27.000> pulsar<00:33:27.680> timing 00:33:28.230 --> 00:33:28.240 align:start position:0% added to a group called a pulsar timing 00:33:28.240 --> 00:33:29.790 align:start position:0% added to a group called a pulsar timing array. 00:33:29.790 --> 00:33:29.800 align:start position:0% array. 00:33:29.800 --> 00:33:32.790 align:start position:0% array. For<00:33:29.960> NANOGrav,<00:33:30.600> they<00:33:30.800> have<00:33:31.040> made<00:33:31.280> use<00:33:31.640> of<00:33:31.880> 68 00:33:32.790 --> 00:33:32.800 align:start position:0% For NANOGrav, they have made use of 68 00:33:32.800 --> 00:33:34.950 align:start position:0% For NANOGrav, they have made use of 68 pulsars,<00:33:33.640> which<00:33:33.800> were<00:33:33.880> chosen<00:33:34.560> for<00:33:34.720> the 00:33:34.950 --> 00:33:34.960 align:start position:0% pulsars, which were chosen for the 00:33:34.960 --> 00:33:37.230 align:start position:0% pulsars, which were chosen for the following<00:33:35.480> special<00:33:35.840> properties. 00:33:37.230 --> 00:33:37.240 align:start position:0% following special properties. 00:33:37.240 --> 00:33:39.350 align:start position:0% following special properties. They<00:33:37.480> had<00:33:37.840> to<00:33:37.960> be<00:33:38.120> spread<00:33:38.680> all<00:33:38.960> across<00:33:39.280> the 00:33:39.350 --> 00:33:39.360 align:start position:0% They had to be spread all across the 00:33:39.360 --> 00:33:41.550 align:start position:0% They had to be spread all across the sky,<00:33:40.280> so<00:33:40.440> we<00:33:40.520> can<00:33:40.680> figure<00:33:40.960> out<00:33:41.160> how<00:33:41.360> these 00:33:41.550 --> 00:33:41.560 align:start position:0% sky, so we can figure out how these 00:33:41.560 --> 00:33:43.070 align:start position:0% sky, so we can figure out how these massive<00:33:41.920> gravitational<00:33:42.480> waves<00:33:42.880> are 00:33:43.070 --> 00:33:43.080 align:start position:0% massive gravitational waves are 00:33:43.080 --> 00:33:46.110 align:start position:0% massive gravitational waves are affecting<00:33:43.480> space-time<00:33:44.160> in<00:33:44.400> all<00:33:44.600> directions. 00:33:46.110 --> 00:33:46.120 align:start position:0% affecting space-time in all directions. 00:33:46.120 --> 00:33:48.630 align:start position:0% affecting space-time in all directions. Also,<00:33:47.080> they<00:33:47.200> had<00:33:47.440> to<00:33:47.520> be<00:33:47.880> millisecond 00:33:48.630 --> 00:33:48.640 align:start position:0% Also, they had to be millisecond 00:33:48.640 --> 00:33:50.790 align:start position:0% Also, they had to be millisecond pulsars,<00:33:49.640> which<00:33:49.840> means<00:33:50.200> they<00:33:50.360> complete 00:33:50.790 --> 00:33:50.800 align:start position:0% pulsars, which means they complete 00:33:50.800 --> 00:33:54.270 align:start position:0% pulsars, which means they complete millions<00:33:51.360> of<00:33:51.480> rotations<00:33:52.200> per<00:33:52.480> second. 00:33:54.270 --> 00:33:54.280 align:start position:0% millions of rotations per second. 00:33:54.280 --> 00:33:56.990 align:start position:0% millions of rotations per second. In<00:33:54.640> our<00:33:54.920> recent<00:33:55.320> pulsar<00:33:55.760> video,<00:33:56.600> we<00:33:56.720> talked 00:33:56.990 --> 00:33:57.000 align:start position:0% In our recent pulsar video, we talked 00:33:57.000 --> 00:33:59.630 align:start position:0% In our recent pulsar video, we talked about<00:33:57.280> how<00:33:57.480> these<00:33:57.800> fast-spinning<00:33:58.880> pulsars 00:33:59.630 --> 00:33:59.640 align:start position:0% about how these fast-spinning pulsars 00:33:59.640 --> 00:34:01.510 align:start position:0% about how these fast-spinning pulsars are<00:33:59.760> expected<00:34:00.320> to<00:34:00.400> be<00:34:00.520> the<00:34:00.600> most<00:34:00.840> stable<00:34:01.400> and 00:34:01.510 --> 00:34:01.520 align:start position:0% are expected to be the most stable and 00:34:01.520 --> 00:34:02.710 align:start position:0% are expected to be the most stable and dependable<00:34:02.080> when<00:34:02.240> it<00:34:02.320> comes<00:34:02.560> to<00:34:02.640> the 00:34:02.710 --> 00:34:02.720 align:start position:0% dependable when it comes to the 00:34:02.720 --> 00:34:04.910 align:start position:0% dependable when it comes to the regularity<00:34:03.440> of<00:34:03.520> their<00:34:03.680> pulses. 00:34:04.910 --> 00:34:04.920 align:start position:0% regularity of their pulses. 00:34:04.920 --> 00:34:07.110 align:start position:0% regularity of their pulses. In<00:34:05.080> fact,<00:34:05.440> their<00:34:05.560> stability<00:34:06.280> even<00:34:06.680> rivals 00:34:07.110 --> 00:34:07.120 align:start position:0% In fact, their stability even rivals 00:34:07.120 --> 00:34:09.990 align:start position:0% In fact, their stability even rivals that<00:34:07.520> of<00:34:07.680> some<00:34:08.080> atomic<00:34:08.480> clocks.<00:34:09.480> We<00:34:09.600> could<00:34:09.760> not 00:34:09.990 --> 00:34:10.000 align:start position:0% that of some atomic clocks. We could not 00:34:10.000 --> 00:34:11.830 align:start position:0% that of some atomic clocks. We could not ask<00:34:10.320> for<00:34:10.440> better<00:34:10.679> timekeepers<00:34:11.280> to<00:34:11.360> be<00:34:11.480> dotted 00:34:11.830 --> 00:34:11.840 align:start position:0% ask for better timekeepers to be dotted 00:34:11.840 --> 00:34:13.990 align:start position:0% ask for better timekeepers to be dotted across<00:34:12.159> space<00:34:12.520> and<00:34:12.679> time. 00:34:13.990 --> 00:34:14.000 align:start position:0% across space and time. 00:34:14.000 --> 00:34:15.909 align:start position:0% across space and time. This<00:34:14.240> regularity<00:34:15.000> means<00:34:15.320> that<00:34:15.440> we<00:34:15.520> can<00:34:15.639> take 00:34:15.909 --> 00:34:15.919 align:start position:0% This regularity means that we can take 00:34:15.919 --> 00:34:17.510 align:start position:0% This regularity means that we can take measurements<00:34:16.480> of<00:34:16.600> the<00:34:16.720> time<00:34:17.000> their<00:34:17.159> pulses 00:34:17.510 --> 00:34:17.520 align:start position:0% measurements of the time their pulses 00:34:17.520 --> 00:34:19.470 align:start position:0% measurements of the time their pulses arrive,<00:34:18.360> and<00:34:18.480> continue<00:34:18.919> taking<00:34:19.280> these 00:34:19.470 --> 00:34:19.480 align:start position:0% arrive, and continue taking these 00:34:19.480 --> 00:34:21.470 align:start position:0% arrive, and continue taking these measurements<00:34:20.000> over<00:34:20.200> multiple<00:34:20.639> years<00:34:21.040> to<00:34:21.200> see 00:34:21.470 --> 00:34:21.480 align:start position:0% measurements over multiple years to see 00:34:21.480 --> 00:34:24.230 align:start position:0% measurements over multiple years to see if<00:34:21.639> there<00:34:21.840> are<00:34:21.919> any<00:34:22.080> changes<00:34:22.520> happening. 00:34:24.230 --> 00:34:24.240 align:start position:0% if there are any changes happening. 00:34:24.240 --> 00:34:27.030 align:start position:0% if there are any changes happening. Of<00:34:24.440> course,<00:34:25.120> the<00:34:25.240> times<00:34:25.600> of<00:34:25.720> arrival<00:34:26.320> can<00:34:26.520> vary 00:34:27.030 --> 00:34:27.040 align:start position:0% Of course, the times of arrival can vary 00:34:27.040 --> 00:34:29.230 align:start position:0% Of course, the times of arrival can vary due<00:34:27.200> to<00:34:27.360> all<00:34:27.520> sorts<00:34:27.879> of<00:34:27.960> factors,<00:34:28.800> such<00:34:29.040> as<00:34:29.159> the 00:34:29.230 --> 00:34:29.240 align:start position:0% due to all sorts of factors, such as the 00:34:29.240 --> 00:34:30.990 align:start position:0% due to all sorts of factors, such as the change<00:34:29.639> in<00:34:29.760> distance<00:34:30.200> between<00:34:30.520> the<00:34:30.639> Earth<00:34:30.919> and 00:34:30.990 --> 00:34:31.000 align:start position:0% change in distance between the Earth and 00:34:31.000 --> 00:34:33.310 align:start position:0% change in distance between the Earth and the<00:34:31.080> pulsar<00:34:32.040> as<00:34:32.240> both<00:34:32.520> objects<00:34:32.919> continue 00:34:33.310 --> 00:34:33.320 align:start position:0% the pulsar as both objects continue 00:34:33.320 --> 00:34:35.430 align:start position:0% the pulsar as both objects continue moving<00:34:33.639> around<00:34:33.960> space,<00:34:34.840> but<00:34:35.000> we<00:34:35.120> can<00:34:35.240> take 00:34:35.430 --> 00:34:35.440 align:start position:0% moving around space, but we can take 00:34:35.440 --> 00:34:38.389 align:start position:0% moving around space, but we can take this<00:34:35.560> into<00:34:35.800> account<00:34:36.240> quite<00:34:36.639> easily. 00:34:38.389 --> 00:34:38.399 align:start position:0% this into account quite easily. 00:34:38.399 --> 00:34:40.510 align:start position:0% this into account quite easily. However,<00:34:39.000> there<00:34:39.280> are<00:34:39.480> less<00:34:40.000> predictable 00:34:40.510 --> 00:34:40.520 align:start position:0% However, there are less predictable 00:34:40.520 --> 00:34:43.190 align:start position:0% However, there are less predictable factors,<00:34:41.320> such<00:34:41.600> as<00:34:41.840> random<00:34:42.280> fluctuations<00:34:43.080> in 00:34:43.190 --> 00:34:43.200 align:start position:0% factors, such as random fluctuations in 00:34:43.200 --> 00:34:44.629 align:start position:0% factors, such as random fluctuations in the<00:34:43.280> interstellar<00:34:43.840> gas<00:34:44.200> the<00:34:44.320> light<00:34:44.520> is 00:34:44.629 --> 00:34:44.639 align:start position:0% the interstellar gas the light is 00:34:44.639 --> 00:34:46.990 align:start position:0% the interstellar gas the light is traveling<00:34:45.080> through,<00:34:45.760> causing<00:34:46.120> delays<00:34:46.720> that 00:34:46.990 --> 00:34:47.000 align:start position:0% traveling through, causing delays that 00:34:47.000 --> 00:34:48.470 align:start position:0% traveling through, causing delays that aren't<00:34:47.280> coming<00:34:47.560> from<00:34:47.760> the<00:34:47.840> stretching<00:34:48.399> of 00:34:48.470 --> 00:34:48.480 align:start position:0% aren't coming from the stretching of 00:34:48.480 --> 00:34:49.750 align:start position:0% aren't coming from the stretching of space-time. 00:34:49.750 --> 00:34:49.760 align:start position:0% space-time. 00:34:49.760 --> 00:34:51.669 align:start position:0% space-time. How<00:34:49.840> do<00:34:49.960> we<00:34:50.040> get<00:34:50.200> rid<00:34:50.360> of<00:34:50.440> the<00:34:50.560> random<00:34:51.000> noise<00:34:51.520> in 00:34:51.669 --> 00:34:51.679 align:start position:0% How do we get rid of the random noise in 00:34:51.679 --> 00:34:54.030 align:start position:0% How do we get rid of the random noise in our<00:34:51.800> data<00:34:52.200> from<00:34:52.360> pulsars<00:34:52.919> located<00:34:53.480> thousands 00:34:54.030 --> 00:34:54.040 align:start position:0% our data from pulsars located thousands 00:34:54.040 --> 00:34:55.990 align:start position:0% our data from pulsars located thousands of<00:34:54.200> light-years<00:34:54.600> away? 00:34:55.990 --> 00:34:56.000 align:start position:0% of light-years away? 00:34:56.000 --> 00:34:58.390 align:start position:0% of light-years away? With<00:34:56.240> statistics,<00:34:57.240> we<00:34:57.360> can<00:34:57.640> isolate<00:34:58.280> the 00:34:58.390 --> 00:34:58.400 align:start position:0% With statistics, we can isolate the 00:34:58.400 --> 00:34:59.990 align:start position:0% With statistics, we can isolate the gravitational<00:34:59.000> wave<00:34:59.240> background<00:34:59.760> from<00:34:59.920> the 00:34:59.990 --> 00:35:00.000 align:start position:0% gravitational wave background from the 00:35:00.000 --> 00:35:02.390 align:start position:0% gravitational wave background from the random<00:35:00.360> noise<00:35:00.840> by<00:35:01.480> considering<00:35:01.800> correlations 00:35:02.390 --> 00:35:02.400 align:start position:0% random noise by considering correlations 00:35:02.400 --> 00:35:04.470 align:start position:0% random noise by considering correlations between<00:35:02.760> pairs<00:35:03.160> of<00:35:03.280> pulsars<00:35:03.840> in<00:35:04.000> the<00:35:04.080> pulsar 00:35:04.470 --> 00:35:04.480 align:start position:0% between pairs of pulsars in the pulsar 00:35:04.480 --> 00:35:06.110 align:start position:0% between pairs of pulsars in the pulsar timing<00:35:04.880> array. 00:35:06.110 --> 00:35:06.120 align:start position:0% timing array. 00:35:06.120 --> 00:35:08.390 align:start position:0% timing array. Just<00:35:06.320> like<00:35:06.520> LIGO,<00:35:07.400> one<00:35:07.680> tunnel<00:35:08.080> isn't 00:35:08.390 --> 00:35:08.400 align:start position:0% Just like LIGO, one tunnel isn't 00:35:08.400 --> 00:35:11.270 align:start position:0% Just like LIGO, one tunnel isn't sufficient.<00:35:09.440> We<00:35:09.520> need<00:35:09.840> two<00:35:10.080> pulsars<00:35:10.720> on<00:35:10.960> each 00:35:11.270 --> 00:35:11.280 align:start position:0% sufficient. We need two pulsars on each 00:35:11.280 --> 00:35:13.710 align:start position:0% sufficient. We need two pulsars on each end<00:35:11.640> of<00:35:11.760> our<00:35:11.920> imaginary<00:35:12.360> tunnels. 00:35:13.710 --> 00:35:13.720 align:start position:0% end of our imaginary tunnels. 00:35:13.720 --> 00:35:15.750 align:start position:0% end of our imaginary tunnels. If<00:35:13.920> similar<00:35:14.280> fluctuations<00:35:14.960> show<00:35:15.160> up<00:35:15.280> with<00:35:15.520> two 00:35:15.750 --> 00:35:15.760 align:start position:0% If similar fluctuations show up with two 00:35:15.760 --> 00:35:18.230 align:start position:0% If similar fluctuations show up with two pulsars,<00:35:16.800> it<00:35:16.920> is<00:35:17.040> unlikely<00:35:17.640> that<00:35:17.800> the<00:35:17.880> random 00:35:18.230 --> 00:35:18.240 align:start position:0% pulsars, it is unlikely that the random 00:35:18.240 --> 00:35:20.070 align:start position:0% pulsars, it is unlikely that the random noise<00:35:18.520> aligned<00:35:18.960> in<00:35:19.080> such<00:35:19.360> a<00:35:19.400> way<00:35:19.640> to<00:35:19.800> make<00:35:19.960> it 00:35:20.070 --> 00:35:20.080 align:start position:0% noise aligned in such a way to make it 00:35:20.080 --> 00:35:22.550 align:start position:0% noise aligned in such a way to make it appear<00:35:20.760> by<00:35:20.920> chance<00:35:21.680> that<00:35:21.800> they<00:35:21.960> are<00:35:22.080> acting<00:35:22.440> in 00:35:22.550 --> 00:35:22.560 align:start position:0% appear by chance that they are acting in 00:35:22.560 --> 00:35:23.990 align:start position:0% appear by chance that they are acting in unison. 00:35:23.990 --> 00:35:24.000 align:start position:0% unison. 00:35:24.000 --> 00:35:26.110 align:start position:0% unison. It<00:35:24.120> is<00:35:24.320> far<00:35:24.680> more<00:35:24.840> likely<00:35:25.360> that<00:35:25.600> there<00:35:25.880> is<00:35:26.040> a 00:35:26.110 --> 00:35:26.120 align:start position:0% It is far more likely that there is a 00:35:26.120 --> 00:35:28.110 align:start position:0% It is far more likely that there is a common<00:35:26.560> cause<00:35:27.000> underlying<00:35:27.600> both<00:35:27.920> those 00:35:28.110 --> 00:35:28.120 align:start position:0% common cause underlying both those 00:35:28.120 --> 00:35:30.550 align:start position:0% common cause underlying both those fluctuations,<00:35:29.400> such<00:35:29.640> as<00:35:29.760> the<00:35:29.880> possibility 00:35:30.550 --> 00:35:30.560 align:start position:0% fluctuations, such as the possibility 00:35:30.560 --> 00:35:32.790 align:start position:0% fluctuations, such as the possibility that<00:35:30.720> the<00:35:30.800> photons<00:35:31.320> from<00:35:31.520> the<00:35:31.640> two<00:35:31.920> pulsars 00:35:32.790 --> 00:35:32.800 align:start position:0% that the photons from the two pulsars 00:35:32.800 --> 00:35:34.990 align:start position:0% that the photons from the two pulsars are<00:35:32.920> riding<00:35:33.320> the<00:35:33.440> same<00:35:33.720> gravitational<00:35:34.360> wave 00:35:34.990 --> 00:35:35.000 align:start position:0% are riding the same gravitational wave 00:35:35.000 --> 00:35:37.230 align:start position:0% are riding the same gravitational wave that<00:35:35.120> are<00:35:35.200> washing<00:35:35.560> by<00:35:35.760> them<00:35:35.880> both. 00:35:37.230 --> 00:35:37.240 align:start position:0% that are washing by them both. 00:35:37.240 --> 00:35:39.150 align:start position:0% that are washing by them both. We<00:35:37.360> can<00:35:37.480> then<00:35:37.720> relate<00:35:38.200> these<00:35:38.480> correlations<00:35:39.040> of 00:35:39.150 --> 00:35:39.160 align:start position:0% We can then relate these correlations of 00:35:39.160 --> 00:35:41.310 align:start position:0% We can then relate these correlations of pulsar<00:35:39.600> pairs<00:35:40.240> with<00:35:40.360> their<00:35:40.520> angular<00:35:40.920> distance 00:35:41.310 --> 00:35:41.320 align:start position:0% pulsar pairs with their angular distance 00:35:41.320 --> 00:35:42.790 align:start position:0% pulsar pairs with their angular distance in<00:35:41.440> the<00:35:41.520> sky. 00:35:42.790 --> 00:35:42.800 align:start position:0% in the sky. 00:35:42.800 --> 00:35:44.390 align:start position:0% in the sky. If<00:35:42.920> there<00:35:43.080> is<00:35:43.200> no<00:35:43.560> gravitational<00:35:44.200> wave 00:35:44.390 --> 00:35:44.400 align:start position:0% If there is no gravitational wave 00:35:44.400 --> 00:35:46.390 align:start position:0% If there is no gravitational wave background,<00:35:45.360> we<00:35:45.440> expect<00:35:45.800> there<00:35:45.920> to<00:35:46.040> be<00:35:46.160> no 00:35:46.390 --> 00:35:46.400 align:start position:0% background, we expect there to be no 00:35:46.400 --> 00:35:48.630 align:start position:0% background, we expect there to be no correlation,<00:35:47.520> and<00:35:47.640> the<00:35:47.760> graph<00:35:48.120> to<00:35:48.240> show<00:35:48.560> a 00:35:48.630 --> 00:35:48.640 align:start position:0% correlation, and the graph to show a 00:35:48.640 --> 00:35:50.910 align:start position:0% correlation, and the graph to show a straight<00:35:49.040> line<00:35:49.320> at<00:35:49.400> zero. 00:35:50.910 --> 00:35:50.920 align:start position:0% straight line at zero. 00:35:50.920 --> 00:35:53.070 align:start position:0% straight line at zero. However,<00:35:51.400> if<00:35:51.600> the<00:35:51.720> data<00:35:52.000> shows<00:35:52.360> a<00:35:52.440> special 00:35:53.070 --> 00:35:53.080 align:start position:0% However, if the data shows a special 00:35:53.080 --> 00:35:56.270 align:start position:0% However, if the data shows a special curve<00:35:53.640> called<00:35:54.120> a<00:35:54.240> Hellings<00:35:54.760> and<00:35:55.000> Downs<00:35:55.440> curve, 00:35:56.270 --> 00:35:56.280 align:start position:0% curve called a Hellings and Downs curve, 00:35:56.280 --> 00:35:58.030 align:start position:0% curve called a Hellings and Downs curve, that<00:35:56.440> would<00:35:56.600> indicate<00:35:57.120> that<00:35:57.320> a<00:35:57.400> gravitational 00:35:58.030 --> 00:35:58.040 align:start position:0% that would indicate that a gravitational 00:35:58.040 --> 00:36:00.230 align:start position:0% that would indicate that a gravitational wave<00:35:58.280> background<00:35:59.040> is<00:35:59.240> responsible<00:36:00.040> for<00:36:00.160> the 00:36:00.230 --> 00:36:00.240 align:start position:0% wave background is responsible for the 00:36:00.240 --> 00:36:01.870 align:start position:0% wave background is responsible for the variances. 00:36:01.870 --> 00:36:01.880 align:start position:0% variances. 00:36:01.880 --> 00:36:04.350 align:start position:0% variances. That's<00:36:02.360> what<00:36:02.680> NANOGrav<00:36:03.360> have<00:36:03.600> succeeded<00:36:04.200> in 00:36:04.350 --> 00:36:04.360 align:start position:0% That's what NANOGrav have succeeded in 00:36:04.360 --> 00:36:05.590 align:start position:0% That's what NANOGrav have succeeded in doing. 00:36:05.590 --> 00:36:05.600 align:start position:0% doing. 00:36:05.600 --> 00:36:08.230 align:start position:0% doing. On<00:36:05.680> the<00:36:05.760> 28th<00:36:06.200> of<00:36:06.320> June,<00:36:06.680> 2023, 00:36:08.230 --> 00:36:08.240 align:start position:0% On the 28th of June, 2023, 00:36:08.240 --> 00:36:10.870 align:start position:0% On the 28th of June, 2023, based<00:36:08.600> on<00:36:08.720> over<00:36:08.960> 15<00:36:09.760> years<00:36:10.160> of<00:36:10.240> continuous 00:36:10.870 --> 00:36:10.880 align:start position:0% based on over 15 years of continuous 00:36:10.880 --> 00:36:13.790 align:start position:0% based on over 15 years of continuous observations<00:36:11.640> of<00:36:11.760> their<00:36:11.960> 68<00:36:12.560> pulsars,<00:36:13.600> they 00:36:13.790 --> 00:36:13.800 align:start position:0% observations of their 68 pulsars, they 00:36:13.800 --> 00:36:15.670 align:start position:0% observations of their 68 pulsars, they announced<00:36:14.360> strong<00:36:15.000> evidence<00:36:15.440> for<00:36:15.560> the 00:36:15.670 --> 00:36:15.680 align:start position:0% announced strong evidence for the 00:36:15.680 --> 00:36:18.590 align:start position:0% announced strong evidence for the gravitational<00:36:16.480> wave<00:36:16.840> background. 00:36:18.590 --> 00:36:18.600 align:start position:0% gravitational wave background. 00:36:18.600 --> 00:36:20.750 align:start position:0% gravitational wave background. This<00:36:19.080> is<00:36:19.280> the<00:36:19.360> graph<00:36:19.920> we've<00:36:20.160> been<00:36:20.400> waiting 00:36:20.750 --> 00:36:20.760 align:start position:0% This is the graph we've been waiting 00:36:20.760 --> 00:36:23.550 align:start position:0% This is the graph we've been waiting for. 00:36:23.550 --> 00:36:23.560 align:start position:0% 00:36:23.560 --> 00:36:25.470 align:start position:0% This<00:36:23.840> is<00:36:24.000> a<00:36:24.080> hallmark<00:36:24.760> of<00:36:24.840> gravitational 00:36:25.470 --> 00:36:25.480 align:start position:0% This is a hallmark of gravitational 00:36:25.480 --> 00:36:28.430 align:start position:0% This is a hallmark of gravitational waves,<00:36:26.280> which<00:36:26.560> stretch<00:36:27.120> along<00:36:27.480> one<00:36:27.640> direction 00:36:28.430 --> 00:36:28.440 align:start position:0% waves, which stretch along one direction 00:36:28.440 --> 00:36:30.350 align:start position:0% waves, which stretch along one direction and<00:36:28.720> squish<00:36:29.440> in<00:36:29.520> the<00:36:29.600> perpendicular 00:36:30.350 --> 00:36:30.360 align:start position:0% and squish in the perpendicular 00:36:30.360 --> 00:36:32.910 align:start position:0% and squish in the perpendicular direction. 00:36:32.910 --> 00:36:32.920 align:start position:0% direction. 00:36:32.920 --> 00:36:34.910 align:start position:0% direction. This<00:36:33.080> is<00:36:33.280> exactly<00:36:33.960> what<00:36:34.200> we<00:36:34.320> are<00:36:34.400> seeing<00:36:34.760> with 00:36:34.910 --> 00:36:34.920 align:start position:0% This is exactly what we are seeing with 00:36:34.920 --> 00:36:36.230 align:start position:0% This is exactly what we are seeing with this<00:36:35.120> graph. 00:36:36.230 --> 00:36:36.240 align:start position:0% this graph. 00:36:36.240 --> 00:36:37.990 align:start position:0% this graph. When<00:36:36.360> pulsars<00:36:36.920> are<00:36:37.000> separated<00:36:37.600> at<00:36:37.680> right 00:36:37.990 --> 00:36:38.000 align:start position:0% When pulsars are separated at right 00:36:38.000 --> 00:36:40.590 align:start position:0% When pulsars are separated at right angles,<00:36:38.800> their<00:36:39.080> photons<00:36:39.720> are<00:36:39.840> experiencing 00:36:40.590 --> 00:36:40.600 align:start position:0% angles, their photons are experiencing 00:36:40.600 --> 00:36:42.670 align:start position:0% angles, their photons are experiencing an<00:36:40.720> opposing<00:36:41.320> effect<00:36:41.920> as<00:36:42.040> they<00:36:42.160> travel<00:36:42.520> to 00:36:42.670 --> 00:36:42.680 align:start position:0% an opposing effect as they travel to 00:36:42.680 --> 00:36:43.790 align:start position:0% an opposing effect as they travel to Earth. 00:36:43.790 --> 00:36:43.800 align:start position:0% Earth. 00:36:43.800 --> 00:36:45.750 align:start position:0% Earth. The<00:36:43.920> error<00:36:44.160> bars<00:36:44.520> in<00:36:44.640> the<00:36:44.720> data<00:36:45.160> appear<00:36:45.480> quite 00:36:45.750 --> 00:36:45.760 align:start position:0% The error bars in the data appear quite 00:36:45.760 --> 00:36:47.470 align:start position:0% The error bars in the data appear quite large,<00:36:46.560> but<00:36:46.680> the<00:36:46.800> researchers<00:36:47.360> have 00:36:47.470 --> 00:36:47.480 align:start position:0% large, but the researchers have 00:36:47.480 --> 00:36:49.430 align:start position:0% large, but the researchers have calculated<00:36:48.240> that<00:36:48.360> the<00:36:48.480> data<00:36:48.840> shows<00:36:49.200> that<00:36:49.320> the 00:36:49.430 --> 00:36:49.440 align:start position:0% calculated that the data shows that the 00:36:49.440 --> 00:36:51.310 align:start position:0% calculated that the data shows that the existence<00:36:49.960> of<00:36:50.200> a<00:36:50.320> gravitational<00:36:51.080> wave 00:36:51.310 --> 00:36:51.320 align:start position:0% existence of a gravitational wave 00:36:51.320 --> 00:36:54.070 align:start position:0% existence of a gravitational wave background<00:36:52.200> is<00:36:52.360> statistically<00:36:53.200> significant 00:36:54.070 --> 00:36:54.080 align:start position:0% background is statistically significant 00:36:54.080 --> 00:36:56.550 align:start position:0% background is statistically significant at<00:36:54.240> the<00:36:54.360> three-sigma<00:36:55.400> level. 00:36:56.550 --> 00:36:56.560 align:start position:0% at the three-sigma level. 00:36:56.560 --> 00:36:58.470 align:start position:0% at the three-sigma level. This<00:36:56.720> means<00:36:57.080> that<00:36:57.240> there's<00:36:57.440> only<00:36:57.760> a<00:36:57.880> one<00:36:58.320> in 00:36:58.470 --> 00:36:58.480 align:start position:0% This means that there's only a one in 00:36:58.480 --> 00:37:01.150 align:start position:0% This means that there's only a one in 1,000<00:36:59.200> chance<00:36:59.600> that<00:36:59.760> this<00:37:00.000> is<00:37:00.120> a<00:37:00.200> false<00:37:00.480> alarm 00:37:01.150 --> 00:37:01.160 align:start position:0% 1,000 chance that this is a false alarm 00:37:01.160 --> 00:37:02.870 align:start position:0% 1,000 chance that this is a false alarm and<00:37:01.280> that<00:37:01.400> this<00:37:01.560> data<00:37:01.920> was<00:37:02.080> the<00:37:02.160> result<00:37:02.720> of 00:37:02.870 --> 00:37:02.880 align:start position:0% and that this data was the result of 00:37:02.880 --> 00:37:04.470 align:start position:0% and that this data was the result of mere<00:37:03.120> chance. 00:37:04.470 --> 00:37:04.480 align:start position:0% mere chance. 00:37:04.480 --> 00:37:06.470 align:start position:0% mere chance. In<00:37:04.600> physics,<00:37:05.160> the<00:37:05.320> five-sigma<00:37:06.000> level<00:37:06.360> is 00:37:06.470 --> 00:37:06.480 align:start position:0% In physics, the five-sigma level is 00:37:06.480 --> 00:37:07.790 align:start position:0% In physics, the five-sigma level is considered<00:37:06.960> the<00:37:07.040> gold<00:37:07.280> standard<00:37:07.680> for 00:37:07.790 --> 00:37:07.800 align:start position:0% considered the gold standard for 00:37:07.800 --> 00:37:10.950 align:start position:0% considered the gold standard for discovery,<00:37:08.880> but<00:37:09.200> three-sigma<00:37:10.080> is<00:37:10.280> still<00:37:10.600> very 00:37:10.950 --> 00:37:10.960 align:start position:0% discovery, but three-sigma is still very 00:37:10.960 --> 00:37:13.070 align:start position:0% discovery, but three-sigma is still very strong<00:37:11.400> evidence. 00:37:13.070 --> 00:37:13.080 align:start position:0% strong evidence. 00:37:13.080 --> 00:37:15.270 align:start position:0% strong evidence. As<00:37:13.200> they<00:37:13.320> collect<00:37:13.760> and<00:37:13.920> analyze<00:37:14.360> more<00:37:14.560> data, 00:37:15.270 --> 00:37:15.280 align:start position:0% As they collect and analyze more data, 00:37:15.280 --> 00:37:17.110 align:start position:0% As they collect and analyze more data, astronomers<00:37:15.840> will<00:37:15.960> be<00:37:16.080> able<00:37:16.320> to<00:37:16.440> reduce<00:37:16.840> those 00:37:17.110 --> 00:37:17.120 align:start position:0% astronomers will be able to reduce those 00:37:17.120 --> 00:37:19.470 align:start position:0% astronomers will be able to reduce those error<00:37:17.360> bars<00:37:18.040> and<00:37:18.200> finally<00:37:18.800> announce<00:37:19.360> an 00:37:19.470 --> 00:37:19.480 align:start position:0% error bars and finally announce an 00:37:19.480 --> 00:37:21.710 align:start position:0% error bars and finally announce an official<00:37:20.080> discovery. 00:37:21.710 --> 00:37:21.720 align:start position:0% official discovery. 00:37:21.720 --> 00:37:24.150 align:start position:0% official discovery. So,<00:37:22.200> what<00:37:22.480> secrets<00:37:23.000> does<00:37:23.240> this<00:37:23.440> gravitational 00:37:24.150 --> 00:37:24.160 align:start position:0% So, what secrets does this gravitational 00:37:24.160 --> 00:37:26.310 align:start position:0% So, what secrets does this gravitational wave<00:37:24.480> background<00:37:25.000> reveal? 00:37:26.310 --> 00:37:26.320 align:start position:0% wave background reveal? 00:37:26.320 --> 00:37:28.110 align:start position:0% wave background reveal? While<00:37:26.480> we<00:37:26.600> cannot<00:37:27.000> pick<00:37:27.200> apart<00:37:27.560> the<00:37:27.640> sources 00:37:28.110 --> 00:37:28.120 align:start position:0% While we cannot pick apart the sources 00:37:28.120 --> 00:37:30.470 align:start position:0% While we cannot pick apart the sources of<00:37:28.240> the<00:37:28.360> collective<00:37:28.800> noise<00:37:29.200> just<00:37:29.560> yet,<00:37:30.400> we 00:37:30.470 --> 00:37:30.480 align:start position:0% of the collective noise just yet, we 00:37:30.480 --> 00:37:31.870 align:start position:0% of the collective noise just yet, we hope<00:37:30.680> that<00:37:30.840> these<00:37:31.040> techniques<00:37:31.560> will 00:37:31.870 --> 00:37:31.880 align:start position:0% hope that these techniques will 00:37:31.880 --> 00:37:33.830 align:start position:0% hope that these techniques will eventually<00:37:32.480> allow<00:37:32.760> us<00:37:32.920> to<00:37:33.080> listen<00:37:33.440> in<00:37:33.680> to 00:37:33.830 --> 00:37:33.840 align:start position:0% eventually allow us to listen in to 00:37:33.840 --> 00:37:35.830 align:start position:0% eventually allow us to listen in to specific<00:37:34.640> supermassive<00:37:35.360> black<00:37:35.680> hole 00:37:35.830 --> 00:37:35.840 align:start position:0% specific supermassive black hole 00:37:35.840 --> 00:37:38.390 align:start position:0% specific supermassive black hole binaries<00:37:36.840> and<00:37:37.000> figure<00:37:37.320> out<00:37:37.600> what<00:37:37.920> the<00:37:38.000> signal 00:37:38.390 --> 00:37:38.400 align:start position:0% binaries and figure out what the signal 00:37:38.400 --> 00:37:40.270 align:start position:0% binaries and figure out what the signal can<00:37:38.560> tell<00:37:38.800> us<00:37:39.040> about<00:37:39.360> the<00:37:39.440> creation<00:37:40.080> of<00:37:40.200> the 00:37:40.270 --> 00:37:40.280 align:start position:0% can tell us about the creation of the 00:37:40.280 --> 00:37:41.750 align:start position:0% can tell us about the creation of the universe. 00:37:41.750 --> 00:37:41.760 align:start position:0% universe. 00:37:41.760 --> 00:37:44.150 align:start position:0% universe. Until<00:37:42.080> then,<00:37:42.800> astronomers<00:37:43.360> will<00:37:43.480> continue<00:37:44.000> to 00:37:44.150 --> 00:37:44.160 align:start position:0% Until then, astronomers will continue to 00:37:44.160 --> 00:37:46.470 align:start position:0% Until then, astronomers will continue to use<00:37:44.360> their<00:37:44.600> galaxy-sized<00:37:45.560> detector<00:37:46.320> to 00:37:46.470 --> 00:37:46.480 align:start position:0% use their galaxy-sized detector to 00:37:46.480 --> 00:37:48.950 align:start position:0% use their galaxy-sized detector to calculate<00:37:47.120> how<00:37:47.440> we<00:37:47.600> are<00:37:47.720> bobbing<00:37:48.160> up<00:37:48.360> and<00:37:48.480> down 00:37:48.950 --> 00:37:48.960 align:start position:0% calculate how we are bobbing up and down 00:37:48.960 --> 00:37:52.230 align:start position:0% calculate how we are bobbing up and down in<00:37:49.080> the<00:37:49.200> turbulent<00:37:49.960> sea<00:37:50.320> of<00:37:50.480> space-time. 00:37:52.230 --> 00:37:52.240 align:start position:0% in the turbulent sea of space-time. 00:37:52.240 --> 00:37:54.590 align:start position:0% in the turbulent sea of space-time. Have<00:37:52.480> you<00:37:52.680> heard<00:37:52.880> about<00:37:53.080> NANOGrav<00:37:53.560> before? 00:37:54.590 --> 00:37:54.600 align:start position:0% Have you heard about NANOGrav before? 00:37:54.600 --> 00:37:56.150 align:start position:0% Have you heard about NANOGrav before? What<00:37:54.720> secrets<00:37:55.040> do<00:37:55.160> you<00:37:55.280> think<00:37:55.520> gravitational 00:37:56.150 --> 00:37:56.160 align:start position:0% What secrets do you think gravitational 00:37:56.160 --> 00:37:58.310 align:start position:0% What secrets do you think gravitational waves<00:37:56.440> could<00:37:56.600> reveal?<00:37:57.640> Let<00:37:57.760> us<00:37:57.880> know<00:37:58.120> in<00:37:58.240> the 00:37:58.310 --> 00:37:58.320 align:start position:0% waves could reveal? Let us know in the 00:37:58.320 --> 00:38:00.710 align:start position:0% waves could reveal? Let us know in the comments<00:37:58.800> below. 00:38:00.710 --> 00:38:00.720 align:start position:0% comments below. 00:38:00.720 --> 00:38:03.510 align:start position:0% comments below. On<00:38:00.800> the<00:38:00.920> 14th<00:38:01.400> of<00:38:01.520> September,<00:38:02.160> 2015, 00:38:03.510 --> 00:38:03.520 align:start position:0% On the 14th of September, 2015, 00:38:03.520 --> 00:38:05.870 align:start position:0% On the 14th of September, 2015, scientists<00:38:04.320> at<00:38:04.480> the<00:38:04.600> Laser<00:38:05.120> Interferometer 00:38:05.870 --> 00:38:05.880 align:start position:0% scientists at the Laser Interferometer 00:38:05.880 --> 00:38:08.510 align:start position:0% scientists at the Laser Interferometer Gravitational<00:38:06.720> Wave<00:38:06.960> Observatory<00:38:07.960> detected 00:38:08.510 --> 00:38:08.520 align:start position:0% Gravitational Wave Observatory detected 00:38:08.520 --> 00:38:11.030 align:start position:0% Gravitational Wave Observatory detected gravitational<00:38:09.400> waves<00:38:09.760> directly<00:38:10.800> for<00:38:10.920> the 00:38:11.030 --> 00:38:11.040 align:start position:0% gravitational waves directly for the 00:38:11.040 --> 00:38:13.870 align:start position:0% gravitational waves directly for the first<00:38:11.480> time.<00:38:12.320> A<00:38:12.440> stunning<00:38:12.920> achievement<00:38:13.720> that 00:38:13.870 --> 00:38:13.880 align:start position:0% first time. A stunning achievement that 00:38:13.880 --> 00:38:17.670 align:start position:0% first time. A stunning achievement that led<00:38:14.120> to<00:38:14.200> the<00:38:14.320> 2017<00:38:15.240> Nobel<00:38:15.640> Prize<00:38:16.040> in<00:38:16.160> Physics. 00:38:17.670 --> 00:38:17.680 align:start position:0% led to the 2017 Nobel Prize in Physics. 00:38:17.680 --> 00:38:19.510 align:start position:0% led to the 2017 Nobel Prize in Physics. Why<00:38:17.840> was<00:38:18.000> this<00:38:18.160> significant? 00:38:19.510 --> 00:38:19.520 align:start position:0% Why was this significant? 00:38:19.520 --> 00:38:21.790 align:start position:0% Why was this significant? Well,<00:38:20.120> here's<00:38:20.360> an<00:38:20.480> analogy. 00:38:21.790 --> 00:38:21.800 align:start position:0% Well, here's an analogy. 00:38:21.800 --> 00:38:24.110 align:start position:0% Well, here's an analogy. Let's<00:38:22.080> imagine<00:38:22.680> that<00:38:22.840> human<00:38:23.120> beings<00:38:23.520> evolved 00:38:24.110 --> 00:38:24.120 align:start position:0% Let's imagine that human beings evolved 00:38:24.120 --> 00:38:26.670 align:start position:0% Let's imagine that human beings evolved without<00:38:24.640> the<00:38:24.760> ability<00:38:25.200> to<00:38:25.320> see<00:38:25.520> light.<00:38:26.480> For 00:38:26.670 --> 00:38:26.680 align:start position:0% without the ability to see light. For 00:38:26.680 --> 00:38:28.830 align:start position:0% without the ability to see light. For thousands<00:38:27.200> of<00:38:27.320> years,<00:38:27.760> we'd<00:38:28.040> fumble<00:38:28.600> in<00:38:28.760> the 00:38:28.830 --> 00:38:28.840 align:start position:0% thousands of years, we'd fumble in the 00:38:28.840 --> 00:38:32.110 align:start position:0% thousands of years, we'd fumble in the dark,<00:38:29.560> relying<00:38:30.040> on<00:38:30.200> our<00:38:30.440> other<00:38:30.640> senses<00:38:31.440> until 00:38:32.110 --> 00:38:32.120 align:start position:0% dark, relying on our other senses until 00:38:32.120 --> 00:38:34.910 align:start position:0% dark, relying on our other senses until one<00:38:32.360> day<00:38:33.080> someone<00:38:33.480> invented<00:38:34.000> a<00:38:34.040> machine<00:38:34.760> that 00:38:34.910 --> 00:38:34.920 align:start position:0% one day someone invented a machine that 00:38:34.920 --> 00:38:37.190 align:start position:0% one day someone invented a machine that could<00:38:35.040> perceive<00:38:35.680> light<00:38:36.040> for<00:38:36.320> us. 00:38:37.190 --> 00:38:37.200 align:start position:0% could perceive light for us. 00:38:37.200 --> 00:38:39.590 align:start position:0% could perceive light for us. In<00:38:37.400> time,<00:38:38.040> we'd<00:38:38.240> see<00:38:38.480> everything<00:38:39.360> from<00:38:39.480> the 00:38:39.590 --> 00:38:39.600 align:start position:0% In time, we'd see everything from the 00:38:39.600 --> 00:38:42.350 align:start position:0% In time, we'd see everything from the tips<00:38:39.960> of<00:38:40.080> our<00:38:40.240> noses<00:38:41.040> to<00:38:41.160> the<00:38:41.280> farthest<00:38:42.000> flung 00:38:42.350 --> 00:38:42.360 align:start position:0% tips of our noses to the farthest flung 00:38:42.360 --> 00:38:43.750 align:start position:0% tips of our noses to the farthest flung galaxies. 00:38:43.750 --> 00:38:43.760 align:start position:0% galaxies. 00:38:43.760 --> 00:38:45.910 align:start position:0% galaxies. This<00:38:43.960> analogy<00:38:44.400> captures<00:38:44.880> the<00:38:45.000> magnificence 00:38:45.910 --> 00:38:45.920 align:start position:0% This analogy captures the magnificence 00:38:45.920 --> 00:38:47.470 align:start position:0% This analogy captures the magnificence of<00:38:46.120> LIGO. 00:38:47.470 --> 00:38:47.480 align:start position:0% of LIGO. 00:38:47.480 --> 00:38:49.750 align:start position:0% of LIGO. It's<00:38:47.720> about<00:38:48.160> much<00:38:48.560> more<00:38:49.000> than<00:38:49.200> proving<00:38:49.720> a 00:38:49.750 --> 00:38:49.760 align:start position:0% It's about much more than proving a 00:38:49.760 --> 00:38:53.030 align:start position:0% It's about much more than proving a scientific<00:38:50.360> prediction.<00:38:51.480> LIGO<00:38:52.000> enables<00:38:52.600> us 00:38:53.030 --> 00:38:53.040 align:start position:0% scientific prediction. LIGO enables us 00:38:53.040 --> 00:38:55.430 align:start position:0% scientific prediction. LIGO enables us to<00:38:53.160> perceive<00:38:53.760> the<00:38:53.880> physical<00:38:54.360> universe<00:38:55.240> and 00:38:55.430 --> 00:38:55.440 align:start position:0% to perceive the physical universe and 00:38:55.440 --> 00:38:58.550 align:start position:0% to perceive the physical universe and understand<00:38:55.920> reality<00:38:56.520> on<00:38:56.720> a<00:38:56.800> new<00:38:57.280> level. 00:38:58.550 --> 00:38:58.560 align:start position:0% understand reality on a new level. 00:38:58.560 --> 00:39:01.270 align:start position:0% understand reality on a new level. Like<00:38:58.840> photons,<00:38:59.720> gravitational<00:39:00.440> waves<00:39:00.880> travel 00:39:01.270 --> 00:39:01.280 align:start position:0% Like photons, gravitational waves travel 00:39:01.280 --> 00:39:03.110 align:start position:0% Like photons, gravitational waves travel at<00:39:01.360> the<00:39:01.480> speed<00:39:01.760> of<00:39:01.840> light<00:39:02.280> as<00:39:02.440> they<00:39:02.640> ripple 00:39:03.110 --> 00:39:03.120 align:start position:0% at the speed of light as they ripple 00:39:03.120 --> 00:39:04.790 align:start position:0% at the speed of light as they ripple across<00:39:03.520> space-time. 00:39:04.790 --> 00:39:04.800 align:start position:0% across space-time. 00:39:04.800 --> 00:39:07.470 align:start position:0% across space-time. Their<00:39:04.960> signals<00:39:05.600> are<00:39:05.920> all<00:39:06.160> around<00:39:06.560> us. 00:39:07.470 --> 00:39:07.480 align:start position:0% Their signals are all around us. 00:39:07.480 --> 00:39:09.510 align:start position:0% Their signals are all around us. By<00:39:07.720> listening<00:39:08.280> for<00:39:08.400> gravitational<00:39:09.080> waves 00:39:09.510 --> 00:39:09.520 align:start position:0% By listening for gravitational waves 00:39:09.520 --> 00:39:10.990 align:start position:0% By listening for gravitational waves with<00:39:09.720> some<00:39:09.920> of<00:39:10.000> the<00:39:10.120> most<00:39:10.360> sensitive 00:39:10.990 --> 00:39:11.000 align:start position:0% with some of the most sensitive 00:39:11.000 --> 00:39:13.710 align:start position:0% with some of the most sensitive instruments<00:39:11.760> ever<00:39:12.040> built,<00:39:12.840> scientists<00:39:13.560> are 00:39:13.710 --> 00:39:13.720 align:start position:0% instruments ever built, scientists are 00:39:13.720 --> 00:39:16.430 align:start position:0% instruments ever built, scientists are recording<00:39:14.320> tremors<00:39:14.960> of<00:39:15.240> distant,<00:39:15.920> violent 00:39:16.430 --> 00:39:16.440 align:start position:0% recording tremors of distant, violent 00:39:16.440 --> 00:39:17.550 align:start position:0% recording tremors of distant, violent events, 00:39:17.550 --> 00:39:17.560 align:start position:0% events, 00:39:17.560 --> 00:39:20.390 align:start position:0% events, the<00:39:17.720> formation<00:39:18.280> of<00:39:18.440> black<00:39:18.800> holes,<00:39:19.720> supernova 00:39:20.390 --> 00:39:20.400 align:start position:0% the formation of black holes, supernova 00:39:20.400 --> 00:39:24.310 align:start position:0% the formation of black holes, supernova explosions,<00:39:21.800> and<00:39:22.480> potentially<00:39:23.640> exotic 00:39:24.310 --> 00:39:24.320 align:start position:0% explosions, and potentially exotic 00:39:24.320 --> 00:39:27.070 align:start position:0% explosions, and potentially exotic phenomena<00:39:25.040> we<00:39:25.200> haven't<00:39:25.600> discovered<00:39:26.040> yet. 00:39:27.070 --> 00:39:27.080 align:start position:0% phenomena we haven't discovered yet. 00:39:27.080 --> 00:39:30.310 align:start position:0% phenomena we haven't discovered yet. So,<00:39:27.680> what<00:39:28.120> are<00:39:28.480> gravitational<00:39:29.160> waves?<00:39:30.000> What 00:39:30.310 --> 00:39:30.320 align:start position:0% So, what are gravitational waves? What 00:39:30.320 --> 00:39:33.430 align:start position:0% So, what are gravitational waves? What causes<00:39:30.760> them?<00:39:31.520> And<00:39:31.800> why<00:39:32.200> is<00:39:32.440> LIGO's<00:39:32.920> ability 00:39:33.430 --> 00:39:33.440 align:start position:0% causes them? And why is LIGO's ability 00:39:33.440 --> 00:39:36.110 align:start position:0% causes them? And why is LIGO's ability to<00:39:33.560> detect<00:39:34.040> them<00:39:34.560> already<00:39:35.080> transforming<00:39:35.840> our 00:39:36.110 --> 00:39:36.120 align:start position:0% to detect them already transforming our 00:39:36.120 --> 00:39:39.430 align:start position:0% to detect them already transforming our understanding<00:39:36.880> of<00:39:37.000> the<00:39:37.120> universe? 00:39:39.430 --> 00:39:39.440 align:start position:0% understanding of the universe? 00:39:39.440 --> 00:39:41.510 align:start position:0% understanding of the universe? I'm<00:39:39.760> Alex<00:39:40.000> McCollgan,<00:39:40.720> and<00:39:40.960> you're<00:39:41.120> watching 00:39:41.510 --> 00:39:41.520 align:start position:0% I'm Alex McCollgan, and you're watching 00:39:41.520 --> 00:39:44.230 align:start position:0% I'm Alex McCollgan, and you're watching Astrium.<00:39:42.320> Join<00:39:42.720> me<00:39:42.840> today<00:39:43.280> as<00:39:43.520> we<00:39:43.680> learn<00:39:43.920> about 00:39:44.230 --> 00:39:44.240 align:start position:0% Astrium. Join me today as we learn about 00:39:44.240 --> 00:39:46.350 align:start position:0% Astrium. Join me today as we learn about gravitational<00:39:44.920> waves,<00:39:45.680> unpack<00:39:46.240> the 00:39:46.350 --> 00:39:46.360 align:start position:0% gravitational waves, unpack the 00:39:46.360 --> 00:39:49.190 align:start position:0% gravitational waves, unpack the groundbreaking<00:39:47.320> technology<00:39:47.880> behind<00:39:48.360> LIGO, 00:39:49.190 --> 00:39:49.200 align:start position:0% groundbreaking technology behind LIGO, 00:39:49.200 --> 00:39:51.390 align:start position:0% groundbreaking technology behind LIGO, and<00:39:49.520> anticipate<00:39:50.320> some<00:39:50.600> of<00:39:50.720> the<00:39:50.840> stunning 00:39:51.390 --> 00:39:51.400 align:start position:0% and anticipate some of the stunning 00:39:51.400 --> 00:39:55.510 align:start position:0% and anticipate some of the stunning developments<00:39:52.200> that<00:39:52.400> lie<00:39:52.640> around<00:39:53.000> the<00:39:53.080> corner. 00:39:55.510 --> 00:39:55.520 align:start position:0% developments that lie around the corner. 00:39:55.520 --> 00:39:57.590 align:start position:0% developments that lie around the corner. Gravitational<00:39:56.200> waves<00:39:56.680> are<00:39:56.920> one<00:39:57.280> of<00:39:57.440> the 00:39:57.590 --> 00:39:57.600 align:start position:0% Gravitational waves are one of the 00:39:57.600 --> 00:39:59.670 align:start position:0% Gravitational waves are one of the stranger<00:39:58.240> implications<00:39:59.040> of<00:39:59.320> Albert 00:39:59.670 --> 00:39:59.680 align:start position:0% stranger implications of Albert 00:39:59.680 --> 00:40:02.710 align:start position:0% stranger implications of Albert Einstein's<00:40:00.320> general<00:40:00.800> theory<00:40:01.200> of<00:40:01.320> relativity. 00:40:02.710 --> 00:40:02.720 align:start position:0% Einstein's general theory of relativity. 00:40:02.720 --> 00:40:05.190 align:start position:0% Einstein's general theory of relativity. As<00:40:03.000> we've<00:40:03.200> covered<00:40:03.560> previously,<00:40:04.560> space-time 00:40:05.190 --> 00:40:05.200 align:start position:0% As we've covered previously, space-time 00:40:05.200 --> 00:40:06.830 align:start position:0% As we've covered previously, space-time is<00:40:05.360> a<00:40:05.400> model<00:40:05.840> that<00:40:06.000> combines<00:40:06.480> the<00:40:06.600> three 00:40:06.830 --> 00:40:06.840 align:start position:0% is a model that combines the three 00:40:06.840 --> 00:40:08.670 align:start position:0% is a model that combines the three dimensions<00:40:07.400> of<00:40:07.520> space<00:40:08.240> and<00:40:08.320> the<00:40:08.400> fourth 00:40:08.670 --> 00:40:08.680 align:start position:0% dimensions of space and the fourth 00:40:08.680 --> 00:40:10.630 align:start position:0% dimensions of space and the fourth dimension<00:40:09.080> of<00:40:09.200> time<00:40:09.840> into<00:40:10.120> a<00:40:10.200> single 00:40:10.630 --> 00:40:10.640 align:start position:0% dimension of time into a single 00:40:10.640 --> 00:40:12.070 align:start position:0% dimension of time into a single manifold. 00:40:12.070 --> 00:40:12.080 align:start position:0% manifold. 00:40:12.080 --> 00:40:14.470 align:start position:0% manifold. All<00:40:12.560> objects<00:40:12.960> with<00:40:13.160> mass<00:40:13.560> create<00:40:14.040> curvature 00:40:14.470 --> 00:40:14.480 align:start position:0% All objects with mass create curvature 00:40:14.480 --> 00:40:17.350 align:start position:0% All objects with mass create curvature in<00:40:14.600> space-time,<00:40:15.720> and<00:40:16.040> objects<00:40:16.520> with<00:40:16.720> a<00:40:16.840> lot<00:40:17.240> of 00:40:17.350 --> 00:40:17.360 align:start position:0% in space-time, and objects with a lot of 00:40:17.360 --> 00:40:20.350 align:start position:0% in space-time, and objects with a lot of mass<00:40:17.920> create<00:40:18.440> a<00:40:18.560> lot<00:40:18.880> of<00:40:19.000> curvature,<00:40:20.000> which<00:40:20.240> we 00:40:20.350 --> 00:40:20.360 align:start position:0% mass create a lot of curvature, which we 00:40:20.360 --> 00:40:23.470 align:start position:0% mass create a lot of curvature, which we experience<00:40:21.200> as<00:40:21.520> gravity. 00:40:23.470 --> 00:40:23.480 align:start position:0% experience as gravity. 00:40:23.480 --> 00:40:25.510 align:start position:0% experience as gravity. A<00:40:23.520> simple<00:40:23.840> way<00:40:24.040> to<00:40:24.200> visualize<00:40:24.840> this<00:40:25.280> is<00:40:25.400> to 00:40:25.510 --> 00:40:25.520 align:start position:0% A simple way to visualize this is to 00:40:25.520 --> 00:40:27.750 align:start position:0% A simple way to visualize this is to think<00:40:25.760> of<00:40:25.880> a<00:40:25.960> pool<00:40:26.280> ball<00:40:26.880> resting<00:40:27.360> on<00:40:27.640> an 00:40:27.750 --> 00:40:27.760 align:start position:0% think of a pool ball resting on an 00:40:27.760 --> 00:40:30.310 align:start position:0% think of a pool ball resting on an elastic<00:40:28.200> surface<00:40:29.200> and<00:40:29.360> a<00:40:29.480> bowling<00:40:29.960> ball 00:40:30.310 --> 00:40:30.320 align:start position:0% elastic surface and a bowling ball 00:40:30.320 --> 00:40:32.710 align:start position:0% elastic surface and a bowling ball resting<00:40:30.800> on<00:40:30.920> that<00:40:31.120> same<00:40:31.360> surface. 00:40:32.710 --> 00:40:32.720 align:start position:0% resting on that same surface. 00:40:32.720 --> 00:40:34.590 align:start position:0% resting on that same surface. The<00:40:32.800> more<00:40:33.040> massive<00:40:33.680> bowling<00:40:34.040> ball<00:40:34.480> will 00:40:34.590 --> 00:40:34.600 align:start position:0% The more massive bowling ball will 00:40:34.600 --> 00:40:36.950 align:start position:0% The more massive bowling ball will create<00:40:35.080> more<00:40:35.400> curvature. 00:40:36.950 --> 00:40:36.960 align:start position:0% create more curvature. 00:40:36.960 --> 00:40:39.270 align:start position:0% create more curvature. As<00:40:37.120> objects<00:40:37.560> move<00:40:37.840> across<00:40:38.160> space-time,<00:40:39.080> that 00:40:39.270 --> 00:40:39.280 align:start position:0% As objects move across space-time, that 00:40:39.280 --> 00:40:42.550 align:start position:0% As objects move across space-time, that curvature<00:40:40.080> changes<00:40:40.520> position<00:40:40.960> with<00:40:41.160> them. 00:40:42.550 --> 00:40:42.560 align:start position:0% curvature changes position with them. 00:40:42.560 --> 00:40:45.070 align:start position:0% curvature changes position with them. One<00:40:42.680> of<00:40:42.760> the<00:40:42.880> amazing<00:40:43.400> consequences<00:40:44.560> is<00:40:44.800> that 00:40:45.070 --> 00:40:45.080 align:start position:0% One of the amazing consequences is that 00:40:45.080 --> 00:40:46.670 align:start position:0% One of the amazing consequences is that when<00:40:45.360> objects<00:40:45.800> of<00:40:45.920> a<00:40:45.960> certain<00:40:46.400> mass 00:40:46.670 --> 00:40:46.680 align:start position:0% when objects of a certain mass 00:40:46.680 --> 00:40:49.670 align:start position:0% when objects of a certain mass accelerate,<00:40:47.880> they<00:40:48.040> can<00:40:48.200> send<00:40:48.680> ripples<00:40:49.320> across 00:40:49.670 --> 00:40:49.680 align:start position:0% accelerate, they can send ripples across 00:40:49.680 --> 00:40:53.030 align:start position:0% accelerate, they can send ripples across space-time<00:40:50.400> as<00:40:50.560> gravitational<00:40:51.480> energy. 00:40:53.030 --> 00:40:53.040 align:start position:0% space-time as gravitational energy. 00:40:53.040 --> 00:40:54.950 align:start position:0% space-time as gravitational energy. While<00:40:53.200> this<00:40:53.400> requires<00:40:54.000> a<00:40:54.080> special<00:40:54.640> set<00:40:54.880> of 00:40:54.950 --> 00:40:54.960 align:start position:0% While this requires a special set of 00:40:54.960 --> 00:40:57.870 align:start position:0% While this requires a special set of conditions,<00:40:56.040> namely<00:40:56.680> a<00:40:56.720> very<00:40:57.000> massive<00:40:57.400> object 00:40:57.870 --> 00:40:57.880 align:start position:0% conditions, namely a very massive object 00:40:57.880 --> 00:40:59.870 align:start position:0% conditions, namely a very massive object undergoing<00:40:58.360> acceleration, 00:40:59.870 --> 00:40:59.880 align:start position:0% undergoing acceleration, 00:40:59.880 --> 00:41:02.390 align:start position:0% undergoing acceleration, such<00:41:00.280> a<00:41:00.400> cataclysmic<00:41:01.280> event<00:41:01.800> would<00:41:01.960> send 00:41:02.390 --> 00:41:02.400 align:start position:0% such a cataclysmic event would send 00:41:02.400 --> 00:41:05.790 align:start position:0% such a cataclysmic event would send ripples<00:41:03.280> or<00:41:03.600> gravitational<00:41:04.480> waves<00:41:05.240> outward 00:41:05.790 --> 00:41:05.800 align:start position:0% ripples or gravitational waves outward 00:41:05.800 --> 00:41:07.590 align:start position:0% ripples or gravitational waves outward at<00:41:05.920> the<00:41:06.000> speed<00:41:06.320> of<00:41:06.440> light. 00:41:07.590 --> 00:41:07.600 align:start position:0% at the speed of light. 00:41:07.600 --> 00:41:10.230 align:start position:0% at the speed of light. Think<00:41:07.800> of<00:41:07.920> them<00:41:08.200> like<00:41:08.640> ripples<00:41:09.200> on<00:41:09.320> a<00:41:09.400> pond, 00:41:10.230 --> 00:41:10.240 align:start position:0% Think of them like ripples on a pond, 00:41:10.240 --> 00:41:12.110 align:start position:0% Think of them like ripples on a pond, but<00:41:10.360> instead<00:41:10.680> of<00:41:10.840> water,<00:41:11.600> they<00:41:11.720> travel 00:41:12.110 --> 00:41:12.120 align:start position:0% but instead of water, they travel 00:41:12.120 --> 00:41:14.510 align:start position:0% but instead of water, they travel through<00:41:12.520> the<00:41:12.640> fabric<00:41:13.040> of<00:41:13.160> space-time<00:41:13.760> in<00:41:14.200> all 00:41:14.510 --> 00:41:14.520 align:start position:0% through the fabric of space-time in all 00:41:14.520 --> 00:41:16.310 align:start position:0% through the fabric of space-time in all directions. 00:41:16.310 --> 00:41:16.320 align:start position:0% directions. 00:41:16.320 --> 00:41:18.110 align:start position:0% directions. As<00:41:16.520> in<00:41:16.680> the<00:41:16.760> pond<00:41:17.080> analogy,<00:41:17.960> these 00:41:18.110 --> 00:41:18.120 align:start position:0% As in the pond analogy, these 00:41:18.120 --> 00:41:19.950 align:start position:0% As in the pond analogy, these disturbances<00:41:18.800> become<00:41:19.200> weaker<00:41:19.720> as<00:41:19.840> they 00:41:19.950 --> 00:41:19.960 align:start position:0% disturbances become weaker as they 00:41:19.960 --> 00:41:21.670 align:start position:0% disturbances become weaker as they radiate<00:41:20.480> outward. 00:41:21.670 --> 00:41:21.680 align:start position:0% radiate outward. 00:41:21.680 --> 00:41:23.990 align:start position:0% radiate outward. To<00:41:21.840> an<00:41:21.920> observer,<00:41:22.920> the<00:41:23.040> distance<00:41:23.520> between 00:41:23.990 --> 00:41:24.000 align:start position:0% To an observer, the distance between 00:41:24.000 --> 00:41:26.510 align:start position:0% To an observer, the distance between objects<00:41:24.800> would<00:41:24.920> appear<00:41:25.240> to<00:41:25.360> expand<00:41:26.320> and 00:41:26.510 --> 00:41:26.520 align:start position:0% objects would appear to expand and 00:41:26.520 --> 00:41:29.870 align:start position:0% objects would appear to expand and shrink<00:41:27.400> as<00:41:27.560> the<00:41:27.680> gravitational<00:41:28.400> wave<00:41:28.640> passes. 00:41:29.870 --> 00:41:29.880 align:start position:0% shrink as the gravitational wave passes. 00:41:29.880 --> 00:41:32.470 align:start position:0% shrink as the gravitational wave passes. Mind-boggling<00:41:30.840> to<00:41:30.960> imagine. 00:41:32.470 --> 00:41:32.480 align:start position:0% Mind-boggling to imagine. 00:41:32.480 --> 00:41:34.390 align:start position:0% Mind-boggling to imagine. Yet,<00:41:33.040> although<00:41:33.360> Einstein<00:41:33.800> predicted<00:41:34.320> the 00:41:34.390 --> 00:41:34.400 align:start position:0% Yet, although Einstein predicted the 00:41:34.400 --> 00:41:36.910 align:start position:0% Yet, although Einstein predicted the existence<00:41:34.960> of<00:41:35.040> gravitational<00:41:35.720> waves,<00:41:36.600> he<00:41:36.720> was 00:41:36.910 --> 00:41:36.920 align:start position:0% existence of gravitational waves, he was 00:41:36.920 --> 00:41:39.270 align:start position:0% existence of gravitational waves, he was pessimistic<00:41:37.760> about<00:41:38.080> our<00:41:38.240> chances<00:41:38.760> of<00:41:39.000> ever 00:41:39.270 --> 00:41:39.280 align:start position:0% pessimistic about our chances of ever 00:41:39.280 --> 00:41:40.830 align:start position:0% pessimistic about our chances of ever detecting<00:41:39.800> them. 00:41:40.830 --> 00:41:40.840 align:start position:0% detecting them. 00:41:40.840 --> 00:41:42.510 align:start position:0% detecting them. He<00:41:40.920> thought<00:41:41.200> that<00:41:41.320> these<00:41:41.560> disturbances<00:41:42.360> would 00:41:42.510 --> 00:41:42.520 align:start position:0% He thought that these disturbances would 00:41:42.520 --> 00:41:45.550 align:start position:0% He thought that these disturbances would be<00:41:42.680> so<00:41:43.120> small<00:41:43.920> as<00:41:44.120> to<00:41:44.240> escape<00:41:44.800> our<00:41:44.960> ability<00:41:45.440> to 00:41:45.550 --> 00:41:45.560 align:start position:0% be so small as to escape our ability to 00:41:45.560 --> 00:41:46.710 align:start position:0% be so small as to escape our ability to measure<00:41:45.840> them. 00:41:46.710 --> 00:41:46.720 align:start position:0% measure them. 00:41:46.720 --> 00:41:49.030 align:start position:0% measure them. And<00:41:47.120> who<00:41:47.280> could<00:41:47.400> blame<00:41:47.720> him?<00:41:48.520> Many<00:41:48.800> of<00:41:48.920> the 00:41:49.030 --> 00:41:49.040 align:start position:0% And who could blame him? Many of the 00:41:49.040 --> 00:41:51.190 align:start position:0% And who could blame him? Many of the changes<00:41:49.480> in<00:41:49.640> distance<00:41:50.080> that<00:41:50.240> LIGO<00:41:50.680> seeks<00:41:51.040> to 00:41:51.190 --> 00:41:51.200 align:start position:0% changes in distance that LIGO seeks to 00:41:51.200 --> 00:41:54.430 align:start position:0% changes in distance that LIGO seeks to measure<00:41:52.040> are<00:41:52.280> 1/10,000 00:41:54.430 --> 00:41:54.440 align:start position:0% measure are 1/10,000 00:41:54.440 --> 00:41:56.590 align:start position:0% measure are 1/10,000 the<00:41:54.600> length<00:41:55.040> of<00:41:55.160> a<00:41:55.200> proton. 00:41:56.590 --> 00:41:56.600 align:start position:0% the length of a proton. 00:41:56.600 --> 00:41:59.750 align:start position:0% the length of a proton. Yes,<00:41:57.040> you<00:41:57.200> heard<00:41:57.360> that<00:41:57.520> correctly.<00:41:58.520> 10,000 00:41:59.750 --> 00:41:59.760 align:start position:0% Yes, you heard that correctly. 10,000 00:41:59.760 --> 00:42:03.590 align:start position:0% Yes, you heard that correctly. 10,000 times<00:42:00.080> smaller<00:42:00.880> than<00:42:01.000> a<00:42:01.080> single<00:42:01.800> proton. 00:42:03.590 --> 00:42:03.600 align:start position:0% times smaller than a single proton. 00:42:03.600 --> 00:42:05.790 align:start position:0% times smaller than a single proton. And<00:42:03.720> yet,<00:42:04.480> these<00:42:04.680> signals<00:42:05.240> would<00:42:05.440> come 00:42:05.790 --> 00:42:05.800 align:start position:0% And yet, these signals would come 00:42:05.800 --> 00:42:07.950 align:start position:0% And yet, these signals would come encoded<00:42:06.480> with<00:42:06.760> all<00:42:07.000> kinds<00:42:07.360> of<00:42:07.440> information 00:42:07.950 --> 00:42:07.960 align:start position:0% encoded with all kinds of information 00:42:07.960 --> 00:42:09.670 align:start position:0% encoded with all kinds of information about<00:42:08.280> their<00:42:08.480> origins. 00:42:09.670 --> 00:42:09.680 align:start position:0% about their origins. 00:42:09.680 --> 00:42:11.710 align:start position:0% about their origins. When<00:42:09.920> they<00:42:10.080> originated,<00:42:11.160> how<00:42:11.320> far<00:42:11.600> they 00:42:11.710 --> 00:42:11.720 align:start position:0% When they originated, how far they 00:42:11.720 --> 00:42:14.070 align:start position:0% When they originated, how far they traveled,<00:42:12.760> and<00:42:13.040> what<00:42:13.320> kind<00:42:13.600> of<00:42:13.720> event 00:42:14.070 --> 00:42:14.080 align:start position:0% traveled, and what kind of event 00:42:14.080 --> 00:42:15.950 align:start position:0% traveled, and what kind of event produced<00:42:14.560> them. 00:42:15.950 --> 00:42:15.960 align:start position:0% produced them. 00:42:15.960 --> 00:42:18.910 align:start position:0% produced them. This<00:42:16.200> is<00:42:16.360> where<00:42:16.800> LIGO<00:42:17.280> comes<00:42:17.640> in. 00:42:18.910 --> 00:42:18.920 align:start position:0% This is where LIGO comes in. 00:42:18.920 --> 00:42:21.750 align:start position:0% This is where LIGO comes in. It<00:42:19.040> consists<00:42:19.800> of<00:42:20.120> two<00:42:20.440> observatories<00:42:21.440> funded 00:42:21.750 --> 00:42:21.760 align:start position:0% It consists of two observatories funded 00:42:21.760 --> 00:42:24.030 align:start position:0% It consists of two observatories funded by<00:42:22.080> the<00:42:22.240> United<00:42:22.720> States<00:42:23.200> National<00:42:23.680> Science 00:42:24.030 --> 00:42:24.040 align:start position:0% by the United States National Science 00:42:24.040 --> 00:42:26.870 align:start position:0% by the United States National Science Foundation<00:42:25.080> and<00:42:25.240> operated<00:42:25.800> by<00:42:26.000> MIT<00:42:26.720> and 00:42:26.870 --> 00:42:26.880 align:start position:0% Foundation and operated by MIT and 00:42:26.880 --> 00:42:28.430 align:start position:0% Foundation and operated by MIT and Caltech. 00:42:28.430 --> 00:42:28.440 align:start position:0% Caltech. 00:42:28.440 --> 00:42:30.790 align:start position:0% Caltech. Among<00:42:28.880> its<00:42:29.040> driving<00:42:29.400> forces<00:42:30.000> are<00:42:30.200> renowned 00:42:30.790 --> 00:42:30.800 align:start position:0% Among its driving forces are renowned 00:42:30.800 --> 00:42:33.910 align:start position:0% Among its driving forces are renowned physicists<00:42:31.520> Kip<00:42:31.800> Thorne,<00:42:32.520> Rainer<00:42:32.800> Weiss,<00:42:33.600> and 00:42:33.910 --> 00:42:33.920 align:start position:0% physicists Kip Thorne, Rainer Weiss, and 00:42:33.920 --> 00:42:35.510 align:start position:0% physicists Kip Thorne, Rainer Weiss, and Barry<00:42:34.280> Barish, 00:42:35.510 --> 00:42:35.520 align:start position:0% Barry Barish, 00:42:35.520 --> 00:42:38.310 align:start position:0% Barry Barish, all<00:42:35.760> of<00:42:35.880> whom<00:42:36.160> shared<00:42:36.480> the<00:42:36.600> 2017<00:42:37.480> Nobel<00:42:37.840> Prize 00:42:38.310 --> 00:42:38.320 align:start position:0% all of whom shared the 2017 Nobel Prize 00:42:38.320 --> 00:42:40.270 align:start position:0% all of whom shared the 2017 Nobel Prize for<00:42:38.480> their<00:42:38.640> decisive<00:42:39.200> contributions<00:42:40.080> to<00:42:40.160> the 00:42:40.270 --> 00:42:40.280 align:start position:0% for their decisive contributions to the 00:42:40.280 --> 00:42:43.870 align:start position:0% for their decisive contributions to the detection<00:42:40.880> of<00:42:41.000> gravitational<00:42:41.760> waves. 00:42:43.870 --> 00:42:43.880 align:start position:0% detection of gravitational waves. 00:42:43.880 --> 00:42:46.990 align:start position:0% detection of gravitational waves. LIGO<00:42:44.360> is<00:42:44.520> essentially<00:42:45.280> a<00:42:45.400> large-scale<00:42:46.600> and 00:42:46.990 --> 00:42:47.000 align:start position:0% LIGO is essentially a large-scale and 00:42:47.000 --> 00:42:49.670 align:start position:0% LIGO is essentially a large-scale and very<00:42:47.440> sensitive<00:42:48.200> interferometer, 00:42:49.670 --> 00:42:49.680 align:start position:0% very sensitive interferometer, 00:42:49.680 --> 00:42:51.230 align:start position:0% very sensitive interferometer, an<00:42:49.760> invention<00:42:50.280> that's<00:42:50.480> been<00:42:50.640> around<00:42:51.000> since 00:42:51.230 --> 00:42:51.240 align:start position:0% an invention that's been around since 00:42:51.240 --> 00:42:53.070 align:start position:0% an invention that's been around since the<00:42:51.360> 1880s. 00:42:53.070 --> 00:42:53.080 align:start position:0% the 1880s. 00:42:53.080 --> 00:42:54.950 align:start position:0% the 1880s. An<00:42:53.120> interferometer<00:42:53.880> essentially<00:42:54.400> measures 00:42:54.950 --> 00:42:54.960 align:start position:0% An interferometer essentially measures 00:42:54.960 --> 00:42:56.470 align:start position:0% An interferometer essentially measures what<00:42:55.200> happens<00:42:55.600> when<00:42:55.800> light<00:42:56.040> waves<00:42:56.400> are 00:42:56.470 --> 00:42:56.480 align:start position:0% what happens when light waves are 00:42:56.480 --> 00:42:59.710 align:start position:0% what happens when light waves are combined<00:42:57.120> from<00:42:57.480> two<00:42:57.840> or<00:42:57.960> more<00:42:58.200> sources. 00:42:59.710 --> 00:42:59.720 align:start position:0% combined from two or more sources. 00:42:59.720 --> 00:43:01.190 align:start position:0% combined from two or more sources. For<00:42:59.760> example,<00:43:00.680> you<00:43:00.800> could<00:43:00.960> use<00:43:01.120> an 00:43:01.190 --> 00:43:01.200 align:start position:0% For example, you could use an 00:43:01.200 --> 00:43:03.110 align:start position:0% For example, you could use an interferometer<00:43:01.960> to<00:43:02.160> test<00:43:02.560> whether<00:43:02.840> light 00:43:03.110 --> 00:43:03.120 align:start position:0% interferometer to test whether light 00:43:03.120 --> 00:43:04.790 align:start position:0% interferometer to test whether light travels<00:43:03.600> at<00:43:03.720> different<00:43:04.080> speeds<00:43:04.560> through 00:43:04.790 --> 00:43:04.800 align:start position:0% travels at different speeds through 00:43:04.800 --> 00:43:06.870 align:start position:0% travels at different speeds through different<00:43:05.120> substances,<00:43:06.160> such<00:43:06.400> as<00:43:06.520> through 00:43:06.870 --> 00:43:06.880 align:start position:0% different substances, such as through 00:43:06.880 --> 00:43:09.270 align:start position:0% different substances, such as through air<00:43:07.440> or<00:43:07.800> water. 00:43:09.270 --> 00:43:09.280 align:start position:0% air or water. 00:43:09.280 --> 00:43:10.950 align:start position:0% air or water. Even<00:43:09.520> a<00:43:09.600> subtle<00:43:09.960> difference<00:43:10.320> in<00:43:10.440> speed<00:43:10.840> will 00:43:10.950 --> 00:43:10.960 align:start position:0% Even a subtle difference in speed will 00:43:10.960 --> 00:43:13.430 align:start position:0% Even a subtle difference in speed will produce<00:43:11.440> an<00:43:11.640> interference<00:43:12.360> pattern<00:43:13.120> when<00:43:13.320> the 00:43:13.430 --> 00:43:13.440 align:start position:0% produce an interference pattern when the 00:43:13.440 --> 00:43:15.630 align:start position:0% produce an interference pattern when the light<00:43:13.800> waves<00:43:14.080> combine,<00:43:15.040> much<00:43:15.280> like<00:43:15.480> what 00:43:15.630 --> 00:43:15.640 align:start position:0% light waves combine, much like what 00:43:15.640 --> 00:43:17.550 align:start position:0% light waves combine, much like what happens<00:43:16.000> when<00:43:16.360> two<00:43:16.640> ripples<00:43:17.080> on<00:43:17.160> a<00:43:17.200> pond 00:43:17.550 --> 00:43:17.560 align:start position:0% happens when two ripples on a pond 00:43:17.560 --> 00:43:18.910 align:start position:0% happens when two ripples on a pond intersect. 00:43:18.910 --> 00:43:18.920 align:start position:0% intersect. 00:43:18.920 --> 00:43:20.670 align:start position:0% intersect. If<00:43:19.040> the<00:43:19.200> peak<00:43:19.560> of<00:43:19.680> one<00:43:19.840> ripple<00:43:20.200> hits<00:43:20.560> the 00:43:20.670 --> 00:43:20.680 align:start position:0% If the peak of one ripple hits the 00:43:20.680 --> 00:43:22.390 align:start position:0% If the peak of one ripple hits the valley<00:43:21.000> of<00:43:21.120> a<00:43:21.160> second<00:43:21.480> ripple,<00:43:22.160> they<00:43:22.280> will 00:43:22.390 --> 00:43:22.400 align:start position:0% valley of a second ripple, they will 00:43:22.400 --> 00:43:24.310 align:start position:0% valley of a second ripple, they will subtract<00:43:22.880> from<00:43:23.000> each<00:43:23.200> other,<00:43:23.680> producing<00:43:24.200> a 00:43:24.310 --> 00:43:24.320 align:start position:0% subtract from each other, producing a 00:43:24.320 --> 00:43:26.030 align:start position:0% subtract from each other, producing a flat<00:43:24.680> surface. 00:43:26.030 --> 00:43:26.040 align:start position:0% flat surface. 00:43:26.040 --> 00:43:28.830 align:start position:0% flat surface. However,<00:43:26.840> if<00:43:26.960> the<00:43:27.080> peaks<00:43:27.400> line<00:43:27.680> up<00:43:27.880> exactly, 00:43:28.830 --> 00:43:28.840 align:start position:0% However, if the peaks line up exactly, 00:43:28.840 --> 00:43:31.310 align:start position:0% However, if the peaks line up exactly, it<00:43:29.000> means<00:43:29.280> that<00:43:29.360> the<00:43:29.480> waves<00:43:29.800> are<00:43:29.960> in<00:43:30.160> phase<00:43:31.080> and 00:43:31.310 --> 00:43:31.320 align:start position:0% it means that the waves are in phase and 00:43:31.320 --> 00:43:32.910 align:start position:0% it means that the waves are in phase and add<00:43:31.640> to<00:43:31.760> each<00:43:31.920> other. 00:43:32.910 --> 00:43:32.920 align:start position:0% add to each other. 00:43:32.920 --> 00:43:34.190 align:start position:0% add to each other. This<00:43:33.080> is<00:43:33.200> essentially<00:43:33.840> what<00:43:34.040> the 00:43:34.190 --> 00:43:34.200 align:start position:0% This is essentially what the 00:43:34.200 --> 00:43:36.870 align:start position:0% This is essentially what the interferometer<00:43:34.960> measures<00:43:35.480> with<00:43:35.720> light. 00:43:36.870 --> 00:43:36.880 align:start position:0% interferometer measures with light. 00:43:36.880 --> 00:43:39.430 align:start position:0% interferometer measures with light. By<00:43:36.960> seeing<00:43:37.320> how<00:43:37.760> in<00:43:38.240> or<00:43:38.520> out<00:43:38.720> of<00:43:38.800> phase<00:43:39.200> two 00:43:39.430 --> 00:43:39.440 align:start position:0% By seeing how in or out of phase two 00:43:39.440 --> 00:43:42.310 align:start position:0% By seeing how in or out of phase two light<00:43:39.680> waves<00:43:40.120> are,<00:43:40.880> an<00:43:41.000> observer<00:43:41.480> can<00:43:41.680> infer 00:43:42.310 --> 00:43:42.320 align:start position:0% light waves are, an observer can infer 00:43:42.320 --> 00:43:44.790 align:start position:0% light waves are, an observer can infer the<00:43:42.480> relative<00:43:43.000> speed<00:43:43.480> of<00:43:43.600> the<00:43:43.720> waves. 00:43:44.790 --> 00:43:44.800 align:start position:0% the relative speed of the waves. 00:43:44.800 --> 00:43:46.910 align:start position:0% the relative speed of the waves. And<00:43:44.880> the<00:43:44.960> larger<00:43:45.760> and<00:43:45.920> more<00:43:46.120> powerful<00:43:46.800> the 00:43:46.910 --> 00:43:46.920 align:start position:0% And the larger and more powerful the 00:43:46.920 --> 00:43:49.150 align:start position:0% And the larger and more powerful the interferometer,<00:43:48.040> the<00:43:48.160> more<00:43:48.440> sensitive<00:43:49.000> it 00:43:49.150 --> 00:43:49.160 align:start position:0% interferometer, the more sensitive it 00:43:49.160 --> 00:43:50.710 align:start position:0% interferometer, the more sensitive it is. 00:43:50.710 --> 00:43:50.720 align:start position:0% is. 00:43:50.720 --> 00:43:52.590 align:start position:0% is. Here's<00:43:51.000> how<00:43:51.160> it<00:43:51.320> works. 00:43:52.590 --> 00:43:52.600 align:start position:0% Here's how it works. 00:43:52.600 --> 00:43:55.270 align:start position:0% Here's how it works. LIGO<00:43:52.920> has<00:43:53.160> two<00:43:53.440> observatories<00:43:54.560> located<00:43:55.080> in 00:43:55.270 --> 00:43:55.280 align:start position:0% LIGO has two observatories located in 00:43:55.280 --> 00:43:58.070 align:start position:0% LIGO has two observatories located in Hanford,<00:43:55.920> Washington,<00:43:57.000> and<00:43:57.360> Livingston, 00:43:58.070 --> 00:43:58.080 align:start position:0% Hanford, Washington, and Livingston, 00:43:58.080 --> 00:43:59.670 align:start position:0% Hanford, Washington, and Livingston, Louisiana. 00:43:59.670 --> 00:43:59.680 align:start position:0% Louisiana. 00:43:59.680 --> 00:44:01.030 align:start position:0% Louisiana. Why<00:43:59.880> two? 00:44:01.030 --> 00:44:01.040 align:start position:0% Why two? 00:44:01.040 --> 00:44:02.910 align:start position:0% Why two? Well,<00:44:01.440> you<00:44:01.600> need<00:44:01.840> at<00:44:01.960> least<00:44:02.240> two<00:44:02.400> detection 00:44:02.910 --> 00:44:02.920 align:start position:0% Well, you need at least two detection 00:44:02.920 --> 00:44:04.910 align:start position:0% Well, you need at least two detection sites<00:44:02.955> [music]<00:44:03.360> to<00:44:03.520> triangulate<00:44:04.520> where<00:44:04.800> the 00:44:04.910 --> 00:44:04.920 align:start position:0% sites [music] to triangulate where the 00:44:04.920 --> 00:44:06.910 align:start position:0% sites [music] to triangulate where the signals<00:44:05.360> are<00:44:05.440> coming<00:44:05.720> from. 00:44:06.910 --> 00:44:06.920 align:start position:0% signals are coming from. 00:44:06.920 --> 00:44:09.030 align:start position:0% signals are coming from. Each<00:44:07.200> observatory<00:44:07.880> continuously<00:44:08.560> fires<00:44:08.960> a 00:44:09.030 --> 00:44:09.040 align:start position:0% Each observatory continuously fires a 00:44:09.040 --> 00:44:11.190 align:start position:0% Each observatory continuously fires a powerful<00:44:09.600> laser<00:44:10.280> at<00:44:10.400> a<00:44:10.440> beam<00:44:10.760> splitter 00:44:11.190 --> 00:44:11.200 align:start position:0% powerful laser at a beam splitter 00:44:11.200 --> 00:44:14.430 align:start position:0% powerful laser at a beam splitter positioned<00:44:11.760> at<00:44:11.920> a<00:44:12.000> 45°<00:44:12.960> angle. 00:44:14.430 --> 00:44:14.440 align:start position:0% positioned at a 45° angle. 00:44:14.440 --> 00:44:16.670 align:start position:0% positioned at a 45° angle. The<00:44:14.560> laser<00:44:14.840> beam<00:44:15.160> has<00:44:15.440> to<00:44:15.560> operate<00:44:16.080> at<00:44:16.240> around 00:44:16.670 --> 00:44:16.680 align:start position:0% The laser beam has to operate at around 00:44:16.680 --> 00:44:18.230 align:start position:0% The laser beam has to operate at around 750 00:44:18.230 --> 00:44:18.240 align:start position:0% 750 00:44:18.240 --> 00:44:19.550 align:start position:0% 750 kW. 00:44:19.550 --> 00:44:19.560 align:start position:0% kW. 00:44:19.560 --> 00:44:21.550 align:start position:0% kW. Powerful<00:44:20.000> enough<00:44:20.440> to<00:44:20.640> vaporize<00:44:21.440> you 00:44:21.550 --> 00:44:21.560 align:start position:0% Powerful enough to vaporize you 00:44:21.560 --> 00:44:24.110 align:start position:0% Powerful enough to vaporize you completely<00:44:22.240> if<00:44:22.360> you<00:44:22.480> got<00:44:22.720> in<00:44:22.800> its<00:44:22.960> path. 00:44:24.110 --> 00:44:24.120 align:start position:0% completely if you got in its path. 00:44:24.120 --> 00:44:26.470 align:start position:0% completely if you got in its path. The<00:44:24.200> splitter<00:44:24.920> then<00:44:25.160> splits<00:44:25.680> the<00:44:25.760> laser<00:44:26.080> beam 00:44:26.470 --> 00:44:26.480 align:start position:0% The splitter then splits the laser beam 00:44:26.480 --> 00:44:28.630 align:start position:0% The splitter then splits the laser beam perpendicularly. 00:44:28.630 --> 00:44:28.640 align:start position:0% perpendicularly. 00:44:28.640 --> 00:44:31.190 align:start position:0% perpendicularly. The<00:44:28.760> light<00:44:29.080> in<00:44:29.280> each<00:44:29.560> arm<00:44:29.920> travels<00:44:30.320> down<00:44:30.680> a<00:44:30.800> 4 00:44:31.190 --> 00:44:31.200 align:start position:0% The light in each arm travels down a 4 00:44:31.200 --> 00:44:33.830 align:start position:0% The light in each arm travels down a 4 km<00:44:31.760> vacuum<00:44:32.200> cavity<00:44:33.000> with<00:44:33.160> a<00:44:33.240> mirror<00:44:33.600> at<00:44:33.680> the 00:44:33.830 --> 00:44:33.840 align:start position:0% km vacuum cavity with a mirror at the 00:44:33.840 --> 00:44:35.070 align:start position:0% km vacuum cavity with a mirror at the end<00:44:33.960> of<00:44:34.080> it. 00:44:35.070 --> 00:44:35.080 align:start position:0% end of it. 00:44:35.080 --> 00:44:36.990 align:start position:0% end of it. The<00:44:35.200> beams<00:44:35.760> then<00:44:36.040> bounce<00:44:36.440> between<00:44:36.840> this 00:44:36.990 --> 00:44:37.000 align:start position:0% The beams then bounce between this 00:44:37.000 --> 00:44:38.950 align:start position:0% The beams then bounce between this mirror<00:44:37.600> and<00:44:37.680> a<00:44:37.720> recycling<00:44:38.360> mirror<00:44:38.680> at<00:44:38.800> the 00:44:38.950 --> 00:44:38.960 align:start position:0% mirror and a recycling mirror at the 00:44:38.960 --> 00:44:42.070 align:start position:0% mirror and a recycling mirror at the other<00:44:39.200> end<00:44:39.560> nearly<00:44:39.880> 300<00:44:40.760> times,<00:44:41.600> increasing 00:44:42.070 --> 00:44:42.080 align:start position:0% other end nearly 300 times, increasing 00:44:42.080 --> 00:44:46.110 align:start position:0% other end nearly 300 times, increasing the<00:44:42.160> distance<00:44:42.720> from<00:44:43.120> 4<00:44:43.960> to<00:44:44.240> 1,200 00:44:46.110 --> 00:44:46.120 align:start position:0% the distance from 4 to 1,200 00:44:46.120 --> 00:44:47.870 align:start position:0% the distance from 4 to 1,200 km. 00:44:47.870 --> 00:44:47.880 align:start position:0% km. 00:44:47.880 --> 00:44:49.590 align:start position:0% km. Remember<00:44:48.200> what<00:44:48.400> we<00:44:48.520> said?<00:44:49.320> With 00:44:49.590 --> 00:44:49.600 align:start position:0% Remember what we said? With 00:44:49.600 --> 00:44:53.030 align:start position:0% Remember what we said? With interferometers,<00:44:50.760> bigger<00:44:51.240> is<00:44:51.480> better. 00:44:53.030 --> 00:44:53.040 align:start position:0% interferometers, bigger is better. 00:44:53.040 --> 00:44:55.910 align:start position:0% interferometers, bigger is better. After<00:44:53.280> completing<00:44:53.840> nearly<00:44:54.160> 300<00:44:55.000> trips,<00:44:55.800> the 00:44:55.910 --> 00:44:55.920 align:start position:0% After completing nearly 300 trips, the 00:44:55.920 --> 00:44:58.430 align:start position:0% After completing nearly 300 trips, the laser<00:44:56.200> beams<00:44:56.520> combine<00:44:57.120> at<00:44:57.240> the<00:44:57.320> beam<00:44:57.560> splitter 00:44:58.430 --> 00:44:58.440 align:start position:0% laser beams combine at the beam splitter 00:44:58.440 --> 00:45:01.190 align:start position:0% laser beams combine at the beam splitter and<00:44:58.640> head<00:44:59.080> to<00:44:59.360> a<00:44:59.440> photodiode,<00:45:00.720> which<00:45:00.920> is<00:45:01.120> a 00:45:01.190 --> 00:45:01.200 align:start position:0% and head to a photodiode, which is a 00:45:01.200 --> 00:45:03.990 align:start position:0% and head to a photodiode, which is a light-sensitive<00:45:02.200> semiconductor. 00:45:03.990 --> 00:45:04.000 align:start position:0% light-sensitive semiconductor. 00:45:04.000 --> 00:45:06.190 align:start position:0% light-sensitive semiconductor. If<00:45:04.160> undisturbed,<00:45:05.280> the<00:45:05.400> beams<00:45:05.800> will<00:45:05.920> be<00:45:06.040> in 00:45:06.190 --> 00:45:06.200 align:start position:0% If undisturbed, the beams will be in 00:45:06.200 --> 00:45:08.390 align:start position:0% If undisturbed, the beams will be in phase,<00:45:07.040> meaning<00:45:07.320> their<00:45:07.480> frequencies<00:45:08.240> will 00:45:08.390 --> 00:45:08.400 align:start position:0% phase, meaning their frequencies will 00:45:08.400 --> 00:45:10.670 align:start position:0% phase, meaning their frequencies will subtract<00:45:08.920> each<00:45:09.120> other<00:45:09.720> and<00:45:09.960> no<00:45:10.160> light<00:45:10.560> will 00:45:10.670 --> 00:45:10.680 align:start position:0% subtract each other and no light will 00:45:10.680 --> 00:45:13.070 align:start position:0% subtract each other and no light will arrive<00:45:11.160> at<00:45:11.280> the<00:45:11.360> photodiode. 00:45:13.070 --> 00:45:13.080 align:start position:0% arrive at the photodiode. 00:45:13.080 --> 00:45:15.670 align:start position:0% arrive at the photodiode. But<00:45:13.280> if<00:45:13.480> there's<00:45:13.680> a<00:45:13.760> gravitational<00:45:14.640> wave,<00:45:15.520> the 00:45:15.670 --> 00:45:15.680 align:start position:0% But if there's a gravitational wave, the 00:45:15.680 --> 00:45:17.950 align:start position:0% But if there's a gravitational wave, the distance<00:45:16.360> each<00:45:16.640> beam<00:45:16.880> travels<00:45:17.680> will<00:45:17.840> be 00:45:17.950 --> 00:45:17.960 align:start position:0% distance each beam travels will be 00:45:17.960 --> 00:45:20.230 align:start position:0% distance each beam travels will be slightly<00:45:18.400> different<00:45:19.320> and<00:45:19.480> they'll<00:45:19.640> be<00:45:19.840> out<00:45:20.120> of 00:45:20.230 --> 00:45:20.240 align:start position:0% slightly different and they'll be out of 00:45:20.240 --> 00:45:21.510 align:start position:0% slightly different and they'll be out of phase. 00:45:21.510 --> 00:45:21.520 align:start position:0% phase. 00:45:21.520 --> 00:45:23.790 align:start position:0% phase. The<00:45:21.600> photodiode<00:45:22.400> will<00:45:22.560> pick<00:45:22.800> up<00:45:22.920> a<00:45:22.960> signal 00:45:23.790 --> 00:45:23.800 align:start position:0% The photodiode will pick up a signal 00:45:23.800 --> 00:45:25.270 align:start position:0% The photodiode will pick up a signal indicating<00:45:24.480> the<00:45:24.600> presence<00:45:25.080> of<00:45:25.200> a 00:45:25.270 --> 00:45:25.280 align:start position:0% indicating the presence of a 00:45:25.280 --> 00:45:27.910 align:start position:0% indicating the presence of a gravitational<00:45:26.040> wave. 00:45:27.910 --> 00:45:27.920 align:start position:0% gravitational wave. 00:45:27.920 --> 00:45:30.110 align:start position:0% gravitational wave. Now,<00:45:28.440> this<00:45:28.640> is<00:45:28.760> how<00:45:28.960> it<00:45:29.120> works<00:45:29.480> in<00:45:29.600> a<00:45:29.680> perfect 00:45:30.110 --> 00:45:30.120 align:start position:0% Now, this is how it works in a perfect 00:45:30.120 --> 00:45:32.630 align:start position:0% Now, this is how it works in a perfect world.<00:45:31.080> But<00:45:31.360> in<00:45:31.480> reality,<00:45:32.520> the 00:45:32.630 --> 00:45:32.640 align:start position:0% world. But in reality, the 00:45:32.640 --> 00:45:34.990 align:start position:0% world. But in reality, the interferometer<00:45:33.440> is<00:45:33.680> constantly<00:45:34.400> picking<00:45:34.760> up 00:45:34.990 --> 00:45:35.000 align:start position:0% interferometer is constantly picking up 00:45:35.000 --> 00:45:36.070 align:start position:0% interferometer is constantly picking up noise. 00:45:36.070 --> 00:45:36.080 align:start position:0% noise. 00:45:36.080 --> 00:45:39.110 align:start position:0% noise. To<00:45:36.200> minimize<00:45:36.680> this,<00:45:37.280> LIGO<00:45:37.680> uses<00:45:38.200> incredibly 00:45:39.110 --> 00:45:39.120 align:start position:0% To minimize this, LIGO uses incredibly 00:45:39.120 --> 00:45:42.590 align:start position:0% To minimize this, LIGO uses incredibly smooth<00:45:39.760> 40<00:45:40.160> kg<00:45:40.720> mirrors<00:45:41.320> suspended<00:45:41.920> by<00:45:42.080> silica 00:45:42.590 --> 00:45:42.600 align:start position:0% smooth 40 kg mirrors suspended by silica 00:45:42.600 --> 00:45:43.910 align:start position:0% smooth 40 kg mirrors suspended by silica threads. 00:45:43.910 --> 00:45:43.920 align:start position:0% threads. 00:45:43.920 --> 00:45:45.790 align:start position:0% threads. Any<00:45:44.200> particles<00:45:44.800> in<00:45:44.960> the<00:45:45.080> interferometers 00:45:45.790 --> 00:45:45.800 align:start position:0% Any particles in the interferometers 00:45:45.800 --> 00:45:48.230 align:start position:0% Any particles in the interferometers arms<00:45:46.320> are<00:45:46.520> also<00:45:46.840> a<00:45:46.880> problem,<00:45:47.680> which<00:45:47.840> is<00:45:48.000> why 00:45:48.230 --> 00:45:48.240 align:start position:0% arms are also a problem, which is why 00:45:48.240 --> 00:45:50.070 align:start position:0% arms are also a problem, which is why LIGO<00:45:48.720> pumps<00:45:49.080> the<00:45:49.240> air<00:45:49.400> from<00:45:49.560> its<00:45:49.720> vacuum 00:45:50.070 --> 00:45:50.080 align:start position:0% LIGO pumps the air from its vacuum 00:45:50.080 --> 00:45:53.190 align:start position:0% LIGO pumps the air from its vacuum chambers<00:45:50.800> to<00:45:51.000> 1<00:45:51.440> trillionth<00:45:52.480> of<00:45:52.680> atmospheric 00:45:53.190 --> 00:45:53.200 align:start position:0% chambers to 1 trillionth of atmospheric 00:45:53.200 --> 00:45:55.190 align:start position:0% chambers to 1 trillionth of atmospheric pressure. 00:45:55.190 --> 00:45:55.200 align:start position:0% pressure. 00:45:55.200 --> 00:45:57.310 align:start position:0% pressure. But<00:45:55.560> there's<00:45:55.760> another<00:45:56.040> problem. 00:45:57.310 --> 00:45:57.320 align:start position:0% But there's another problem. 00:45:57.320 --> 00:46:00.590 align:start position:0% But there's another problem. At<00:45:57.520> these<00:45:57.840> minuscule<00:45:58.720> levels,<00:45:59.640> even<00:46:00.120> quantum 00:46:00.590 --> 00:46:00.600 align:start position:0% At these minuscule levels, even quantum 00:46:00.600 --> 00:46:02.710 align:start position:0% At these minuscule levels, even quantum mechanics<00:46:01.320> are<00:46:01.440> a<00:46:01.520> nuisance<00:46:02.280> because<00:46:02.600> they 00:46:02.710 --> 00:46:02.720 align:start position:0% mechanics are a nuisance because they 00:46:02.720 --> 00:46:04.630 align:start position:0% mechanics are a nuisance because they introduce<00:46:03.240> randomness<00:46:04.000> into<00:46:04.240> photon 00:46:04.630 --> 00:46:04.640 align:start position:0% introduce randomness into photon 00:46:04.640 --> 00:46:06.110 align:start position:0% introduce randomness into photon behavior. 00:46:06.110 --> 00:46:06.120 align:start position:0% behavior. 00:46:06.120 --> 00:46:08.670 align:start position:0% behavior. LIGO<00:46:06.560> mitigates<00:46:07.120> this<00:46:07.640> with<00:46:07.960> an<00:46:08.160> optical 00:46:08.670 --> 00:46:08.680 align:start position:0% LIGO mitigates this with an optical 00:46:08.680 --> 00:46:11.670 align:start position:0% LIGO mitigates this with an optical cavity,<00:46:09.360> which<00:46:09.680> squeezes<00:46:10.360> the<00:46:10.480> light. 00:46:11.670 --> 00:46:11.680 align:start position:0% cavity, which squeezes the light. 00:46:11.680 --> 00:46:13.830 align:start position:0% cavity, which squeezes the light. This<00:46:11.880> squeezing<00:46:12.880> minimizes<00:46:13.480> the<00:46:13.600> light 00:46:13.830 --> 00:46:13.840 align:start position:0% This squeezing minimizes the light 00:46:13.840 --> 00:46:16.310 align:start position:0% This squeezing minimizes the light phases<00:46:14.240> noise<00:46:15.000> and<00:46:15.160> squeezes<00:46:15.640> it<00:46:15.840> into 00:46:16.310 --> 00:46:16.320 align:start position:0% phases noise and squeezes it into 00:46:16.320 --> 00:46:18.070 align:start position:0% phases noise and squeezes it into amplitude<00:46:16.920> noise,<00:46:17.680> which<00:46:17.880> the 00:46:18.070 --> 00:46:18.080 align:start position:0% amplitude noise, which the 00:46:18.080 --> 00:46:20.550 align:start position:0% amplitude noise, which the interferometer<00:46:18.840> doesn't<00:46:19.280> measure. 00:46:20.550 --> 00:46:20.560 align:start position:0% interferometer doesn't measure. 00:46:20.560 --> 00:46:22.910 align:start position:0% interferometer doesn't measure. In<00:46:20.680> other<00:46:20.840> words,<00:46:21.560> the<00:46:21.680> quantum<00:46:22.160> randomness 00:46:22.910 --> 00:46:22.920 align:start position:0% In other words, the quantum randomness 00:46:22.920 --> 00:46:24.910 align:start position:0% In other words, the quantum randomness will<00:46:23.080> show<00:46:23.280> up<00:46:23.440> more<00:46:24.080> in<00:46:24.240> the<00:46:24.360> height<00:46:24.720> of<00:46:24.840> the 00:46:24.910 --> 00:46:24.920 align:start position:0% will show up more in the height of the 00:46:24.920 --> 00:46:26.870 align:start position:0% will show up more in the height of the waves. 00:46:26.870 --> 00:46:26.880 align:start position:0% waves. 00:46:26.880 --> 00:46:29.750 align:start position:0% waves. Quantum<00:46:27.240> randomness<00:46:27.920> is<00:46:28.200> a<00:46:28.280> fact<00:46:28.680> of<00:46:28.800> life.<00:46:29.600> It 00:46:29.750 --> 00:46:29.760 align:start position:0% Quantum randomness is a fact of life. It 00:46:29.760 --> 00:46:31.830 align:start position:0% Quantum randomness is a fact of life. It can't<00:46:30.080> be<00:46:30.200> eliminated,<00:46:31.240> but<00:46:31.360> it<00:46:31.480> can<00:46:31.680> be 00:46:31.830 --> 00:46:31.840 align:start position:0% can't be eliminated, but it can be 00:46:31.840 --> 00:46:34.430 align:start position:0% can't be eliminated, but it can be shifted.<00:46:32.920> Much<00:46:33.160> as<00:46:33.240> you<00:46:33.360> might<00:46:33.680> move<00:46:33.960> clutter 00:46:34.430 --> 00:46:34.440 align:start position:0% shifted. Much as you might move clutter 00:46:34.440 --> 00:46:36.950 align:start position:0% shifted. Much as you might move clutter from<00:46:34.680> your<00:46:34.880> bedroom<00:46:35.280> floor<00:46:35.640> to<00:46:35.720> your<00:46:35.880> closet. 00:46:36.950 --> 00:46:36.960 align:start position:0% from your bedroom floor to your closet. 00:46:36.960 --> 00:46:39.270 align:start position:0% from your bedroom floor to your closet. The<00:46:37.000> chaos<00:46:37.400> isn't<00:46:37.720> gone,<00:46:38.520> just<00:46:38.720> out<00:46:38.880> of<00:46:39.000> sight 00:46:39.270 --> 00:46:39.280 align:start position:0% The chaos isn't gone, just out of sight 00:46:39.280 --> 00:46:40.590 align:start position:0% The chaos isn't gone, just out of sight for<00:46:39.400> the<00:46:39.480> moment. 00:46:40.590 --> 00:46:40.600 align:start position:0% for the moment. 00:46:40.600 --> 00:46:42.390 align:start position:0% for the moment. Plus,<00:46:40.840> the<00:46:40.960> goal<00:46:41.240> isn't<00:46:41.520> to<00:46:41.600> eliminate<00:46:42.160> noise 00:46:42.390 --> 00:46:42.400 align:start position:0% Plus, the goal isn't to eliminate noise 00:46:42.400 --> 00:46:45.030 align:start position:0% Plus, the goal isn't to eliminate noise completely,<00:46:43.320> but<00:46:43.480> to<00:46:43.600> get<00:46:43.960> the<00:46:44.120> best<00:46:44.600> signal 00:46:45.030 --> 00:46:45.040 align:start position:0% completely, but to get the best signal 00:46:45.040 --> 00:46:47.870 align:start position:0% completely, but to get the best signal to<00:46:45.120> noise<00:46:45.400> ratio<00:46:45.800> possible. 00:46:47.870 --> 00:46:47.880 align:start position:0% to noise ratio possible. 00:46:47.880 --> 00:46:49.790 align:start position:0% to noise ratio possible. That's<00:46:48.240> a<00:46:48.360> pretty<00:46:48.680> good<00:46:48.920> overview<00:46:49.400> of<00:46:49.600> how 00:46:49.790 --> 00:46:49.800 align:start position:0% That's a pretty good overview of how 00:46:49.800 --> 00:46:51.350 align:start position:0% That's a pretty good overview of how LIGO<00:46:50.200> works. 00:46:51.350 --> 00:46:51.360 align:start position:0% LIGO works. 00:46:51.360 --> 00:46:53.790 align:start position:0% LIGO works. So,<00:46:51.800> what<00:46:52.080> has<00:46:52.240> it<00:46:52.360> discovered? 00:46:53.790 --> 00:46:53.800 align:start position:0% So, what has it discovered? 00:46:53.800 --> 00:46:56.070 align:start position:0% So, what has it discovered? As<00:46:53.960> I<00:46:54.000> mentioned<00:46:54.440> earlier,<00:46:55.080> LIGO<00:46:55.480> detected 00:46:56.070 --> 00:46:56.080 align:start position:0% As I mentioned earlier, LIGO detected 00:46:56.080 --> 00:46:59.070 align:start position:0% As I mentioned earlier, LIGO detected its<00:46:56.280> first<00:46:56.520> signal<00:46:56.960> in<00:46:57.120> 2015. 00:46:59.070 --> 00:46:59.080 align:start position:0% its first signal in 2015. 00:46:59.080 --> 00:47:02.830 align:start position:0% its first signal in 2015. Named<00:46:59.480> GW150914, 00:47:02.830 --> 00:47:02.840 align:start position:0% 00:47:02.840 --> 00:47:04.910 align:start position:0% scientists<00:47:03.440> studied<00:47:03.800> the<00:47:03.920> data<00:47:04.520> and<00:47:04.680> learned 00:47:04.910 --> 00:47:04.920 align:start position:0% scientists studied the data and learned 00:47:04.920 --> 00:47:07.070 align:start position:0% scientists studied the data and learned that<00:47:05.040> it<00:47:05.120> was<00:47:05.280> caused<00:47:05.720> by<00:47:05.840> the<00:47:05.960> merger<00:47:06.400> of<00:47:06.680> two 00:47:07.070 --> 00:47:07.080 align:start position:0% that it was caused by the merger of two 00:47:07.080 --> 00:47:09.870 align:start position:0% that it was caused by the merger of two black<00:47:07.400> holes<00:47:08.200> about<00:47:08.560> 1.6<00:47:09.400> billion 00:47:09.870 --> 00:47:09.880 align:start position:0% black holes about 1.6 billion 00:47:09.880 --> 00:47:11.670 align:start position:0% black holes about 1.6 billion light-years<00:47:10.280> away. 00:47:11.670 --> 00:47:11.680 align:start position:0% light-years away. 00:47:11.680 --> 00:47:14.590 align:start position:0% light-years away. These<00:47:11.840> black<00:47:12.080> holes,<00:47:12.680> which<00:47:12.880> were<00:47:13.000> 29<00:47:13.800> and<00:47:14.040> 36 00:47:14.590 --> 00:47:14.600 align:start position:0% These black holes, which were 29 and 36 00:47:14.600 --> 00:47:17.310 align:start position:0% These black holes, which were 29 and 36 solar<00:47:14.880> masses,<00:47:15.680> became<00:47:16.080> a<00:47:16.160> binary<00:47:17.160> and 00:47:17.310 --> 00:47:17.320 align:start position:0% solar masses, became a binary and 00:47:17.320 --> 00:47:19.310 align:start position:0% solar masses, became a binary and spiraled<00:47:17.920> around<00:47:18.240> each<00:47:18.400> other<00:47:18.920> until<00:47:19.160> they 00:47:19.310 --> 00:47:19.320 align:start position:0% spiraled around each other until they 00:47:19.320 --> 00:47:21.870 align:start position:0% spiraled around each other until they merged<00:47:20.120> and<00:47:20.240> released<00:47:20.600> a<00:47:20.680> blast<00:47:21.320> in<00:47:21.440> the<00:47:21.520> final 00:47:21.870 --> 00:47:21.880 align:start position:0% merged and released a blast in the final 00:47:21.880 --> 00:47:25.710 align:start position:0% merged and released a blast in the final 20<00:47:22.360> milliseconds<00:47:23.560> that<00:47:23.720> was<00:47:24.040> so<00:47:24.400> powerful. 00:47:25.710 --> 00:47:25.720 align:start position:0% 20 milliseconds that was so powerful. 00:47:25.720 --> 00:47:27.870 align:start position:0% 20 milliseconds that was so powerful. Now,<00:47:26.200> get<00:47:26.360> ready<00:47:26.640> for<00:47:26.760> this<00:47:26.960> number<00:47:27.320> because 00:47:27.870 --> 00:47:27.880 align:start position:0% Now, get ready for this number because 00:47:27.880 --> 00:47:29.910 align:start position:0% Now, get ready for this number because this<00:47:28.120> is<00:47:28.360> what<00:47:28.560> the<00:47:28.640> scientists<00:47:29.400> actually 00:47:29.910 --> 00:47:29.920 align:start position:0% this is what the scientists actually 00:47:29.920 --> 00:47:30.990 align:start position:0% this is what the scientists actually think. 00:47:30.990 --> 00:47:31.000 align:start position:0% think. 00:47:31.000 --> 00:47:34.670 align:start position:0% think. It<00:47:31.240> contained<00:47:32.240> 50<00:47:32.840> times<00:47:33.720> the<00:47:33.840> combined<00:47:34.440> light 00:47:34.670 --> 00:47:34.680 align:start position:0% It contained 50 times the combined light 00:47:34.680 --> 00:47:37.710 align:start position:0% It contained 50 times the combined light power<00:47:35.360> of<00:47:35.720> every<00:47:36.160> star<00:47:36.800> in<00:47:36.920> the<00:47:37.040> observable 00:47:37.710 --> 00:47:37.720 align:start position:0% power of every star in the observable 00:47:37.720 --> 00:47:39.630 align:start position:0% power of every star in the observable universe. 00:47:39.630 --> 00:47:39.640 align:start position:0% universe. 00:47:39.640 --> 00:47:42.350 align:start position:0% universe. At<00:47:39.760> the<00:47:39.840> risk<00:47:40.120> of<00:47:40.240> sounding<00:47:40.640> crude,<00:47:41.440> that<00:47:41.960> is 00:47:42.350 --> 00:47:42.360 align:start position:0% At the risk of sounding crude, that is 00:47:42.360 --> 00:47:43.830 align:start position:0% At the risk of sounding crude, that is nuts. 00:47:43.830 --> 00:47:43.840 align:start position:0% nuts. 00:47:43.840 --> 00:47:46.110 align:start position:0% nuts. I've<00:47:44.040> read<00:47:44.200> this<00:47:44.360> fact<00:47:44.800> many<00:47:45.040> times<00:47:45.400> over<00:47:46.000> and 00:47:46.110 --> 00:47:46.120 align:start position:0% I've read this fact many times over and 00:47:46.120 --> 00:47:49.190 align:start position:0% I've read this fact many times over and I<00:47:46.200> still<00:47:46.640> cannot<00:47:47.200> comprehend<00:47:47.840> what<00:47:48.000> it<00:47:48.080> means. 00:47:49.190 --> 00:47:49.200 align:start position:0% I still cannot comprehend what it means. 00:47:49.200 --> 00:47:52.590 align:start position:0% I still cannot comprehend what it means. Yet,<00:47:49.840> after<00:47:50.080> traveling<00:47:50.600> for<00:47:50.920> 1.6<00:47:52.120> billion 00:47:52.590 --> 00:47:52.600 align:start position:0% Yet, after traveling for 1.6 billion 00:47:52.600 --> 00:47:55.430 align:start position:0% Yet, after traveling for 1.6 billion years<00:47:53.320> and<00:47:53.480> finally<00:47:54.040> reaching<00:47:54.440> LIGO,<00:47:55.320> the 00:47:55.430 --> 00:47:55.440 align:start position:0% years and finally reaching LIGO, the 00:47:55.440 --> 00:47:57.870 align:start position:0% years and finally reaching LIGO, the disturbance<00:47:56.120> was<00:47:56.320> so<00:47:56.600> faint,<00:47:57.400> it<00:47:57.600> moved 00:47:57.870 --> 00:47:57.880 align:start position:0% disturbance was so faint, it moved 00:47:57.880 --> 00:48:01.870 align:start position:0% disturbance was so faint, it moved LIGO's<00:47:58.480> 4-km<00:47:59.280> arm<00:48:00.000> 1/1000<00:48:01.200> of<00:48:01.320> the<00:48:01.440> width<00:48:01.720> of<00:48:01.840> a 00:48:01.870 --> 00:48:01.880 align:start position:0% LIGO's 4-km arm 1/1000 of the width of a 00:48:01.880 --> 00:48:03.630 align:start position:0% LIGO's 4-km arm 1/1000 of the width of a proton. 00:48:03.630 --> 00:48:03.640 align:start position:0% proton. 00:48:03.640 --> 00:48:05.390 align:start position:0% proton. To<00:48:03.720> visualize<00:48:04.360> this, 00:48:05.390 --> 00:48:05.400 align:start position:0% To visualize this, 00:48:05.400 --> 00:48:07.910 align:start position:0% To visualize this, imagine<00:48:05.920> the<00:48:06.000> distance<00:48:06.480> between<00:48:06.960> us<00:48:07.680> and 00:48:07.910 --> 00:48:07.920 align:start position:0% imagine the distance between us and 00:48:07.920 --> 00:48:10.110 align:start position:0% imagine the distance between us and Proxima<00:48:08.680> Centauri 00:48:10.110 --> 00:48:10.120 align:start position:0% Proxima Centauri 00:48:10.120 --> 00:48:12.510 align:start position:0% Proxima Centauri and<00:48:10.280> changing<00:48:10.800> it<00:48:11.080> the<00:48:11.280> width<00:48:11.960> of<00:48:12.080> a<00:48:12.160> human 00:48:12.510 --> 00:48:12.520 align:start position:0% and changing it the width of a human 00:48:12.520 --> 00:48:13.790 align:start position:0% and changing it the width of a human hair. 00:48:13.790 --> 00:48:13.800 align:start position:0% hair. 00:48:13.800 --> 00:48:16.710 align:start position:0% hair. That<00:48:14.320> is<00:48:14.520> the<00:48:14.680> level<00:48:15.080> of<00:48:15.200> precision<00:48:15.920> LIGO<00:48:16.480> was 00:48:16.710 --> 00:48:16.720 align:start position:0% That is the level of precision LIGO was 00:48:16.720 --> 00:48:18.670 align:start position:0% That is the level of precision LIGO was able<00:48:17.000> to<00:48:17.120> detect. 00:48:18.670 --> 00:48:18.680 align:start position:0% able to detect. 00:48:18.680 --> 00:48:19.990 align:start position:0% able to detect. If<00:48:18.800> that's<00:48:19.080> not<00:48:19.320> one<00:48:19.480> of<00:48:19.560> the<00:48:19.680> most 00:48:19.990 --> 00:48:20.000 align:start position:0% If that's not one of the most 00:48:20.000 --> 00:48:22.630 align:start position:0% If that's not one of the most astonishing<00:48:20.920> feats<00:48:21.320> in<00:48:21.440> human<00:48:21.760> history,<00:48:22.560> I 00:48:22.630 --> 00:48:22.640 align:start position:0% astonishing feats in human history, I 00:48:22.640 --> 00:48:24.750 align:start position:0% astonishing feats in human history, I don't<00:48:22.840> know<00:48:22.960> what<00:48:23.200> is. 00:48:24.750 --> 00:48:24.760 align:start position:0% don't know what is. 00:48:24.760 --> 00:48:25.990 align:start position:0% don't know what is. And<00:48:25.000> this<00:48:25.160> was<00:48:25.360> just<00:48:25.640> the<00:48:25.720> first 00:48:25.990 --> 00:48:26.000 align:start position:0% And this was just the first 00:48:26.000 --> 00:48:28.510 align:start position:0% And this was just the first gravitational<00:48:26.640> wave<00:48:26.920> LIGO<00:48:27.240> detected. 00:48:28.510 --> 00:48:28.520 align:start position:0% gravitational wave LIGO detected. 00:48:28.520 --> 00:48:30.870 align:start position:0% gravitational wave LIGO detected. The<00:48:28.640> second<00:48:29.120> detection<00:48:29.760> occurred<00:48:30.320> 3<00:48:30.600> months 00:48:30.870 --> 00:48:30.880 align:start position:0% The second detection occurred 3 months 00:48:30.880 --> 00:48:33.830 align:start position:0% The second detection occurred 3 months later<00:48:31.480> in<00:48:31.600> December<00:48:32.040> 2015. 00:48:33.830 --> 00:48:33.840 align:start position:0% later in December 2015. 00:48:33.840 --> 00:48:35.790 align:start position:0% later in December 2015. That<00:48:34.000> signal<00:48:34.480> also<00:48:34.800> came<00:48:35.080> from<00:48:35.240> a<00:48:35.320> black<00:48:35.600> hole 00:48:35.790 --> 00:48:35.800 align:start position:0% That signal also came from a black hole 00:48:35.800 --> 00:48:38.670 align:start position:0% That signal also came from a black hole merger,<00:48:36.520> which<00:48:36.720> took<00:48:36.920> place<00:48:37.280> 1.4<00:48:38.240> billion 00:48:38.670 --> 00:48:38.680 align:start position:0% merger, which took place 1.4 billion 00:48:38.680 --> 00:48:40.270 align:start position:0% merger, which took place 1.4 billion light-years<00:48:39.080> away. 00:48:40.270 --> 00:48:40.280 align:start position:0% light-years away. 00:48:40.280 --> 00:48:42.470 align:start position:0% light-years away. Over<00:48:40.480> its<00:48:40.600> initial<00:48:40.960> three<00:48:41.320> runs,<00:48:42.120> LIGO 00:48:42.470 --> 00:48:42.480 align:start position:0% Over its initial three runs, LIGO 00:48:42.480 --> 00:48:44.350 align:start position:0% Over its initial three runs, LIGO recorded<00:48:42.960> more<00:48:43.120> than<00:48:43.400> 80<00:48:43.840> black<00:48:44.160> hole 00:48:44.350 --> 00:48:44.360 align:start position:0% recorded more than 80 black hole 00:48:44.360 --> 00:48:47.990 align:start position:0% recorded more than 80 black hole mergers,<00:48:45.320> and<00:48:45.480> in<00:48:45.680> August<00:48:46.120> 2017,<00:48:47.360> it<00:48:47.480> detected 00:48:47.990 --> 00:48:48.000 align:start position:0% mergers, and in August 2017, it detected 00:48:48.000 --> 00:48:50.990 align:start position:0% mergers, and in August 2017, it detected the<00:48:48.080> merger<00:48:48.480> of<00:48:48.720> two<00:48:49.200> neutron<00:48:49.640> stars. 00:48:50.990 --> 00:48:51.000 align:start position:0% the merger of two neutron stars. 00:48:51.000 --> 00:48:54.510 align:start position:0% the merger of two neutron stars. Named<00:48:51.360> GW170817, 00:48:54.510 --> 00:48:54.520 align:start position:0% 00:48:54.520 --> 00:48:56.670 align:start position:0% this<00:48:54.760> signal<00:48:55.240> was<00:48:55.440> notable<00:48:56.200> for<00:48:56.320> being<00:48:56.560> the 00:48:56.670 --> 00:48:56.680 align:start position:0% this signal was notable for being the 00:48:56.680 --> 00:48:58.470 align:start position:0% this signal was notable for being the first<00:48:57.120> gravitational<00:48:57.760> wave<00:48:58.200> to<00:48:58.320> be 00:48:58.470 --> 00:48:58.480 align:start position:0% first gravitational wave to be 00:48:58.480 --> 00:49:00.710 align:start position:0% first gravitational wave to be corroborated<00:48:59.560> by<00:48:59.760> electromagnetic 00:49:00.710 --> 00:49:00.720 align:start position:0% corroborated by electromagnetic 00:49:00.720 --> 00:49:03.270 align:start position:0% corroborated by electromagnetic observations<00:49:01.640> from<00:49:01.840> 70<00:49:02.560> observatories 00:49:03.270 --> 00:49:03.280 align:start position:0% observations from 70 observatories 00:49:03.280 --> 00:49:05.070 align:start position:0% observations from 70 observatories across<00:49:03.603> [music]<00:49:03.680> the<00:49:03.760> planet. 00:49:05.070 --> 00:49:05.080 align:start position:0% across [music] the planet. 00:49:05.080 --> 00:49:07.150 align:start position:0% across [music] the planet. This<00:49:05.280> was<00:49:05.520> a<00:49:05.600> breakthrough,<00:49:06.560> not<00:49:06.840> only<00:49:07.080> in 00:49:07.150 --> 00:49:07.160 align:start position:0% This was a breakthrough, not only in 00:49:07.160 --> 00:49:09.350 align:start position:0% This was a breakthrough, not only in gravitational<00:49:07.800> wave<00:49:08.000> detection,<00:49:09.000> but<00:49:09.200> in 00:49:09.350 --> 00:49:09.360 align:start position:0% gravitational wave detection, but in 00:49:09.360 --> 00:49:12.510 align:start position:0% gravitational wave detection, but in multi-messenger<00:49:10.320> astronomy. 00:49:12.510 --> 00:49:12.520 align:start position:0% multi-messenger astronomy. 00:49:12.520 --> 00:49:15.350 align:start position:0% multi-messenger astronomy. It<00:49:12.640> turns<00:49:12.960> out<00:49:13.680> LIGO<00:49:14.120> was<00:49:14.320> just<00:49:14.720> warming<00:49:15.120> up 00:49:15.350 --> 00:49:15.360 align:start position:0% It turns out LIGO was just warming up 00:49:15.360 --> 00:49:17.390 align:start position:0% It turns out LIGO was just warming up during<00:49:15.640> these<00:49:15.840> three<00:49:16.160> runs. 00:49:17.390 --> 00:49:17.400 align:start position:0% during these three runs. 00:49:17.400 --> 00:49:19.790 align:start position:0% during these three runs. As<00:49:17.600> of<00:49:17.760> May<00:49:18.120> 2023, 00:49:19.790 --> 00:49:19.800 align:start position:0% As of May 2023, 00:49:19.800 --> 00:49:22.070 align:start position:0% As of May 2023, LIGO<00:49:20.240> has<00:49:20.400> begun<00:49:20.720> its<00:49:20.880> fourth<00:49:21.280> run<00:49:21.800> with 00:49:22.070 --> 00:49:22.080 align:start position:0% LIGO has begun its fourth run with 00:49:22.080 --> 00:49:24.870 align:start position:0% LIGO has begun its fourth run with better<00:49:22.440> sensitivity<00:49:23.200> than<00:49:23.440> ever. 00:49:24.870 --> 00:49:24.880 align:start position:0% better sensitivity than ever. 00:49:24.880 --> 00:49:26.950 align:start position:0% better sensitivity than ever. After<00:49:25.160> its<00:49:25.320> latest<00:49:25.680> round<00:49:26.000> of<00:49:26.120> upgrades, 00:49:26.950 --> 00:49:26.960 align:start position:0% After its latest round of upgrades, 00:49:26.960 --> 00:49:29.750 align:start position:0% After its latest round of upgrades, which<00:49:27.160> kept<00:49:27.440> LIGO<00:49:27.800> offline<00:49:28.280> for<00:49:28.400> 3<00:49:28.800> years,<00:49:29.640> the 00:49:29.750 --> 00:49:29.760 align:start position:0% which kept LIGO offline for 3 years, the 00:49:29.760 --> 00:49:31.750 align:start position:0% which kept LIGO offline for 3 years, the observatories<00:49:30.440> now<00:49:30.760> have<00:49:31.040> more<00:49:31.280> reflective 00:49:31.750 --> 00:49:31.760 align:start position:0% observatories now have more reflective 00:49:31.760 --> 00:49:34.470 align:start position:0% observatories now have more reflective mirrors,<00:49:32.640> better<00:49:33.000> mirror<00:49:33.240> suspension,<00:49:34.360> and 00:49:34.470 --> 00:49:34.480 align:start position:0% mirrors, better mirror suspension, and 00:49:34.480 --> 00:49:36.550 align:start position:0% mirrors, better mirror suspension, and improved<00:49:35.040> light<00:49:35.280> squeezing<00:49:36.000> with<00:49:36.240> lower 00:49:36.550 --> 00:49:36.560 align:start position:0% improved light squeezing with lower 00:49:36.560 --> 00:49:38.670 align:start position:0% improved light squeezing with lower quantum<00:49:37.000> uncertainty. 00:49:38.670 --> 00:49:38.680 align:start position:0% quantum uncertainty. 00:49:38.680 --> 00:49:41.590 align:start position:0% quantum uncertainty. And<00:49:38.920> this<00:49:39.160> time,<00:49:39.760> LIGO<00:49:40.240> also<00:49:40.560> has<00:49:40.760> the<00:49:40.880> support 00:49:41.590 --> 00:49:41.600 align:start position:0% And this time, LIGO also has the support 00:49:41.600 --> 00:49:43.230 align:start position:0% And this time, LIGO also has the support of<00:49:41.840> KAGRA, 00:49:43.230 --> 00:49:43.240 align:start position:0% of KAGRA, 00:49:43.240 --> 00:49:45.430 align:start position:0% of KAGRA, a<00:49:43.280> new<00:49:43.560> interferometer<00:49:44.320> observatory<00:49:45.280> in 00:49:45.430 --> 00:49:45.440 align:start position:0% a new interferometer observatory in 00:49:45.440 --> 00:49:47.550 align:start position:0% a new interferometer observatory in Hida,<00:49:45.800> Japan. 00:49:47.550 --> 00:49:47.560 align:start position:0% Hida, Japan. 00:49:47.560 --> 00:49:50.510 align:start position:0% Hida, Japan. KAGRA<00:49:48.240> is<00:49:48.360> located<00:49:48.920> underground,<00:49:50.080> making<00:49:50.400> it 00:49:50.510 --> 00:49:50.520 align:start position:0% KAGRA is located underground, making it 00:49:50.520 --> 00:49:52.590 align:start position:0% KAGRA is located underground, making it the<00:49:50.640> world's<00:49:51.200> first<00:49:51.880> subterranean 00:49:52.590 --> 00:49:52.600 align:start position:0% the world's first subterranean 00:49:52.600 --> 00:49:55.350 align:start position:0% the world's first subterranean gravitational<00:49:53.320> wave<00:49:53.560> observatory<00:49:54.680> and<00:49:54.960> also 00:49:55.350 --> 00:49:55.360 align:start position:0% gravitational wave observatory and also 00:49:55.360 --> 00:49:58.830 align:start position:0% gravitational wave observatory and also the<00:49:55.480> first<00:49:55.800> to<00:49:55.880> use<00:49:56.160> cryogenic<00:49:57.120> mirrors. 00:49:58.830 --> 00:49:58.840 align:start position:0% the first to use cryogenic mirrors. 00:49:58.840 --> 00:50:01.070 align:start position:0% the first to use cryogenic mirrors. During<00:49:59.240> an<00:49:59.360> engineering<00:49:59.960> run<00:50:00.240> on<00:50:00.400> the<00:50:00.560> 18th<00:50:00.960> of 00:50:01.070 --> 00:50:01.080 align:start position:0% During an engineering run on the 18th of 00:50:01.080 --> 00:50:03.950 align:start position:0% During an engineering run on the 18th of May,<00:50:01.920> LIGO<00:50:02.320> scientists<00:50:02.880> say<00:50:03.160> they<00:50:03.480> already 00:50:03.950 --> 00:50:03.960 align:start position:0% May, LIGO scientists say they already 00:50:03.960 --> 00:50:05.910 align:start position:0% May, LIGO scientists say they already received<00:50:04.360> a<00:50:04.440> signal<00:50:05.080> that<00:50:05.200> was<00:50:05.400> possibly 00:50:05.910 --> 00:50:05.920 align:start position:0% received a signal that was possibly 00:50:05.920 --> 00:50:08.190 align:start position:0% received a signal that was possibly caused<00:50:06.320> by<00:50:06.480> a<00:50:06.520> neutron<00:50:07.000> star<00:50:07.400> being<00:50:07.680> swallowed 00:50:08.190 --> 00:50:08.200 align:start position:0% caused by a neutron star being swallowed 00:50:08.200 --> 00:50:09.790 align:start position:0% caused by a neutron star being swallowed by<00:50:08.320> a<00:50:08.400> black<00:50:08.720> hole. 00:50:09.790 --> 00:50:09.800 align:start position:0% by a black hole. 00:50:09.800 --> 00:50:11.110 align:start position:0% by a black hole. We'll<00:50:10.000> have<00:50:10.160> to<00:50:10.280> wait<00:50:10.520> a<00:50:10.600> while<00:50:10.880> for 00:50:11.110 --> 00:50:11.120 align:start position:0% We'll have to wait a while for 00:50:11.120 --> 00:50:14.550 align:start position:0% We'll have to wait a while for confirmation,<00:50:12.480> but<00:50:13.160> if<00:50:13.360> these<00:50:13.720> early<00:50:14.000> results 00:50:14.550 --> 00:50:14.560 align:start position:0% confirmation, but if these early results 00:50:14.560 --> 00:50:17.550 align:start position:0% confirmation, but if these early results are<00:50:14.880> any<00:50:15.160> indication,<00:50:16.360> LIGO<00:50:16.960> is<00:50:17.120> about<00:50:17.440> to 00:50:17.550 --> 00:50:17.560 align:start position:0% are any indication, LIGO is about to 00:50:17.560 --> 00:50:20.150 align:start position:0% are any indication, LIGO is about to blow<00:50:18.040> the<00:50:18.160> doors<00:50:18.680> off<00:50:18.960> our<00:50:19.200> understanding<00:50:20.000> of 00:50:20.150 --> 00:50:20.160 align:start position:0% blow the doors off our understanding of 00:50:20.160 --> 00:50:24.070 align:start position:0% blow the doors off our understanding of gravitational<00:50:20.920> wave<00:50:21.320> generating<00:50:21.960> phenomena. 00:50:24.070 --> 00:50:24.080 align:start position:0% gravitational wave generating phenomena. 00:50:24.080 --> 00:50:27.430 align:start position:0% gravitational wave generating phenomena. So,<00:50:25.000> what<00:50:25.400> other<00:50:25.600> developments<00:50:26.120> lie<00:50:26.280> ahead? 00:50:27.430 --> 00:50:27.440 align:start position:0% So, what other developments lie ahead? 00:50:27.440 --> 00:50:29.430 align:start position:0% So, what other developments lie ahead? India<00:50:27.960> is<00:50:28.120> preparing<00:50:28.760> a<00:50:28.840> collaborative 00:50:29.430 --> 00:50:29.440 align:start position:0% India is preparing a collaborative 00:50:29.440 --> 00:50:33.110 align:start position:0% India is preparing a collaborative project<00:50:29.920> called<00:50:30.320> LIGO-India<00:50:31.640> or<00:50:32.040> INDIGO, 00:50:33.110 --> 00:50:33.120 align:start position:0% project called LIGO-India or INDIGO, 00:50:33.120 --> 00:50:35.350 align:start position:0% project called LIGO-India or INDIGO, which<00:50:33.320> will<00:50:33.480> help<00:50:33.800> LIGO<00:50:34.240> triangulate<00:50:35.040> better 00:50:35.350 --> 00:50:35.360 align:start position:0% which will help LIGO triangulate better 00:50:35.360 --> 00:50:37.110 align:start position:0% which will help LIGO triangulate better location<00:50:35.840> data. 00:50:37.110 --> 00:50:37.120 align:start position:0% location data. 00:50:37.120 --> 00:50:41.150 align:start position:0% location data. In<00:50:37.400> 2027<00:50:38.360> to<00:50:38.480> 2028,<00:50:39.840> LIGO<00:50:40.200> will<00:50:40.360> implement<00:50:40.960> its 00:50:41.150 --> 00:50:41.160 align:start position:0% In 2027 to 2028, LIGO will implement its 00:50:41.160 --> 00:50:43.790 align:start position:0% In 2027 to 2028, LIGO will implement its LIGO-Voyager<00:50:42.160> upgrade,<00:50:43.080> which<00:50:43.240> will<00:50:43.360> achieve 00:50:43.790 --> 00:50:43.800 align:start position:0% LIGO-Voyager upgrade, which will achieve 00:50:43.800 --> 00:50:46.150 align:start position:0% LIGO-Voyager upgrade, which will achieve higher<00:50:44.120> sensitivity<00:50:45.080> with<00:50:45.400> four<00:50:45.720> times 00:50:46.150 --> 00:50:46.160 align:start position:0% higher sensitivity with four times 00:50:46.160 --> 00:50:48.310 align:start position:0% higher sensitivity with four times heavier<00:50:46.560> mirrors<00:50:47.280> and<00:50:47.480> higher<00:50:47.840> frequency 00:50:48.310 --> 00:50:48.320 align:start position:0% heavier mirrors and higher frequency 00:50:48.320 --> 00:50:49.590 align:start position:0% heavier mirrors and higher frequency lasers. 00:50:49.590 --> 00:50:49.600 align:start position:0% lasers. 00:50:49.600 --> 00:50:51.830 align:start position:0% lasers. And<00:50:49.880> in<00:50:49.960> the<00:50:50.120> more<00:50:50.520> distant<00:50:50.880> future,<00:50:51.760> a 00:50:51.830 --> 00:50:51.840 align:start position:0% And in the more distant future, a 00:50:51.840 --> 00:50:53.670 align:start position:0% And in the more distant future, a third-generation<00:50:52.640> facility<00:50:53.240> has<00:50:53.520> been 00:50:53.670 --> 00:50:53.680 align:start position:0% third-generation facility has been 00:50:53.680 --> 00:50:57.070 align:start position:0% third-generation facility has been proposed<00:50:54.600> called<00:50:54.880> Cosmic<00:50:55.400> Explorer. 00:50:57.070 --> 00:50:57.080 align:start position:0% proposed called Cosmic Explorer. 00:50:57.080 --> 00:50:59.310 align:start position:0% proposed called Cosmic Explorer. This<00:50:57.360> facility<00:50:57.920> would<00:50:58.120> feature<00:50:58.520> two<00:50:59.080> new 00:50:59.310 --> 00:50:59.320 align:start position:0% This facility would feature two new 00:50:59.320 --> 00:51:02.670 align:start position:0% This facility would feature two new observatories<00:51:00.440> with<00:51:00.680> arms<00:51:01.000> spanning<00:51:01.480> 40<00:51:01.920> km 00:51:02.670 --> 00:51:02.680 align:start position:0% observatories with arms spanning 40 km 00:51:02.680 --> 00:51:05.230 align:start position:0% observatories with arms spanning 40 km and<00:51:02.880> 20<00:51:03.320> km<00:51:03.840> respectively. 00:51:05.230 --> 00:51:05.240 align:start position:0% and 20 km respectively. 00:51:05.240 --> 00:51:07.750 align:start position:0% and 20 km respectively. Remember,<00:51:06.000> with<00:51:06.160> interferometers,<00:51:07.320> bigger 00:51:07.750 --> 00:51:07.760 align:start position:0% Remember, with interferometers, bigger 00:51:07.760 --> 00:51:09.430 align:start position:0% Remember, with interferometers, bigger is<00:51:07.960> better. 00:51:09.430 --> 00:51:09.440 align:start position:0% is better. 00:51:09.440 --> 00:51:12.270 align:start position:0% is better. But<00:51:09.640> the<00:51:09.720> proposal<00:51:10.320> that<00:51:10.720> really<00:51:11.240> excites<00:51:11.680> me 00:51:12.270 --> 00:51:12.280 align:start position:0% But the proposal that really excites me 00:51:12.280 --> 00:51:14.710 align:start position:0% But the proposal that really excites me is<00:51:12.400> the<00:51:12.520> Laser<00:51:13.040> Interferometer<00:51:14.000> Space 00:51:14.710 --> 00:51:14.720 align:start position:0% is the Laser Interferometer Space 00:51:14.720 --> 00:51:17.710 align:start position:0% is the Laser Interferometer Space Antenna<00:51:15.800> or<00:51:16.040> LISA. 00:51:17.710 --> 00:51:17.720 align:start position:0% Antenna or LISA. 00:51:17.720 --> 00:51:20.110 align:start position:0% Antenna or LISA. This<00:51:17.960> would<00:51:18.080> be<00:51:18.200> the<00:51:18.320> first<00:51:18.920> space-based 00:51:20.110 --> 00:51:20.120 align:start position:0% This would be the first space-based 00:51:20.120 --> 00:51:22.350 align:start position:0% This would be the first space-based gravitational<00:51:20.760> wave<00:51:21.040> observatory,<00:51:22.200> which 00:51:22.350 --> 00:51:22.360 align:start position:0% gravitational wave observatory, which 00:51:22.360 --> 00:51:26.190 align:start position:0% gravitational wave observatory, which would<00:51:22.520> utilize<00:51:23.120> three<00:51:23.520> spacecraft<00:51:24.600> in<00:51:24.760> a<00:51:24.840> 2.5 00:51:26.190 --> 00:51:26.200 align:start position:0% would utilize three spacecraft in a 2.5 00:51:26.200 --> 00:51:29.230 align:start position:0% would utilize three spacecraft in a 2.5 million-kilometer-long<00:51:27.480> configuration. 00:51:29.230 --> 00:51:29.240 align:start position:0% million-kilometer-long configuration. 00:51:29.240 --> 00:51:31.990 align:start position:0% million-kilometer-long configuration. This<00:51:29.480> interferometer<00:51:30.360> would<00:51:30.560> be<00:51:30.720> so<00:51:31.160> big<00:51:31.760> and 00:51:31.990 --> 00:51:32.000 align:start position:0% This interferometer would be so big and 00:51:32.000 --> 00:51:34.910 align:start position:0% This interferometer would be so big and so<00:51:32.360> precise,<00:51:33.520> scientists<00:51:34.040> hope<00:51:34.520> it<00:51:34.640> would<00:51:34.800> be 00:51:34.910 --> 00:51:34.920 align:start position:0% so precise, scientists hope it would be 00:51:34.920 --> 00:51:37.470 align:start position:0% so precise, scientists hope it would be adept<00:51:35.440> at<00:51:35.640> uncovering<00:51:36.320> exotic<00:51:37.320> and 00:51:37.470 --> 00:51:37.480 align:start position:0% adept at uncovering exotic and 00:51:37.480 --> 00:51:39.590 align:start position:0% adept at uncovering exotic and theoretical<00:51:38.280> sources<00:51:38.800> of<00:51:38.920> gravitational 00:51:39.590 --> 00:51:39.600 align:start position:0% theoretical sources of gravitational 00:51:39.600 --> 00:51:42.630 align:start position:0% theoretical sources of gravitational waves,<00:51:40.400> such<00:51:40.640> as<00:51:40.760> cosmic<00:51:41.240> strings<00:51:42.080> and<00:51:42.360> other 00:51:42.630 --> 00:51:42.640 align:start position:0% waves, such as cosmic strings and other 00:51:42.640 --> 00:51:45.350 align:start position:0% waves, such as cosmic strings and other speculative<00:51:43.440> phenomena. 00:51:45.350 --> 00:51:45.360 align:start position:0% speculative phenomena. 00:51:45.360 --> 00:51:47.630 align:start position:0% speculative phenomena. In<00:51:45.640> theory,<00:51:46.360> it<00:51:46.560> could<00:51:46.880> help<00:51:47.120> us<00:51:47.320> stare 00:51:47.630 --> 00:51:47.640 align:start position:0% In theory, it could help us stare 00:51:47.640 --> 00:51:51.030 align:start position:0% In theory, it could help us stare directly<00:51:48.560> into<00:51:48.800> the<00:51:48.920> fabric<00:51:49.440> of<00:51:49.560> reality. 00:51:51.030 --> 00:51:51.040 align:start position:0% directly into the fabric of reality. 00:51:51.040 --> 00:51:53.870 align:start position:0% directly into the fabric of reality. With<00:51:51.160> a<00:51:51.240> planned<00:51:51.640> launch<00:51:51.920> date<00:51:52.200> of<00:51:52.360> 2037, 00:51:53.870 --> 00:51:53.880 align:start position:0% With a planned launch date of 2037, 00:51:53.880 --> 00:51:56.030 align:start position:0% With a planned launch date of 2037, we're<00:51:54.000> still<00:51:54.320> over<00:51:54.520> a<00:51:54.560> decade<00:51:54.960> away,<00:51:55.760> but<00:51:55.880> it's 00:51:56.030 --> 00:51:56.040 align:start position:0% we're still over a decade away, but it's 00:51:56.040 --> 00:51:57.870 align:start position:0% we're still over a decade away, but it's never<00:51:56.400> too<00:51:56.640> early<00:51:56.920> to<00:51:57.040> start<00:51:57.320> counting<00:51:57.720> the 00:51:57.870 --> 00:51:57.880 align:start position:0% never too early to start counting the 00:51:57.880 --> 00:51:59.430 align:start position:0% never too early to start counting the years. 00:51:59.430 --> 00:51:59.440 align:start position:0% years. 00:51:59.440 --> 00:52:01.630 align:start position:0% years. So,<00:52:00.160> there<00:52:00.400> you<00:52:00.520> have<00:52:00.760> it. 00:52:01.630 --> 00:52:01.640 align:start position:0% So, there you have it. 00:52:01.640 --> 00:52:04.470 align:start position:0% So, there you have it. An<00:52:01.800> overview<00:52:02.360> of<00:52:02.520> LIGO<00:52:03.280> and<00:52:03.440> how<00:52:03.720> scientists 00:52:04.470 --> 00:52:04.480 align:start position:0% An overview of LIGO and how scientists 00:52:04.480 --> 00:52:06.630 align:start position:0% An overview of LIGO and how scientists are<00:52:04.600> using<00:52:04.920> gravitational<00:52:05.560> waves<00:52:06.000> to<00:52:06.160> better 00:52:06.630 --> 00:52:06.640 align:start position:0% are using gravitational waves to better 00:52:06.640 --> 00:52:08.630 align:start position:0% are using gravitational waves to better understand<00:52:07.200> the<00:52:07.320> universe. 00:52:08.630 --> 00:52:08.640 align:start position:0% understand the universe. 00:52:08.640 --> 00:52:11.030 align:start position:0% understand the universe. They<00:52:08.760> give<00:52:09.000> us<00:52:09.280> evidence<00:52:10.120> of<00:52:10.200> extremely 00:52:11.030 --> 00:52:11.040 align:start position:0% They give us evidence of extremely 00:52:11.040 --> 00:52:13.470 align:start position:0% They give us evidence of extremely remote<00:52:11.600> and<00:52:11.840> ancient<00:52:12.200> phenomena<00:52:12.920> that<00:52:13.120> cannot 00:52:13.470 --> 00:52:13.480 align:start position:0% remote and ancient phenomena that cannot 00:52:13.480 --> 00:52:15.630 align:start position:0% remote and ancient phenomena that cannot be<00:52:13.640> measured<00:52:14.080> by<00:52:14.280> other<00:52:14.520> means.<00:52:15.440> And<00:52:15.520> they 00:52:15.630 --> 00:52:15.640 align:start position:0% be measured by other means. And they 00:52:15.640 --> 00:52:17.630 align:start position:0% be measured by other means. And they could<00:52:15.760> be<00:52:15.920> a<00:52:16.000> secondary<00:52:16.640> way<00:52:17.080> to<00:52:17.240> measure 00:52:17.630 --> 00:52:17.640 align:start position:0% could be a secondary way to measure 00:52:17.640 --> 00:52:20.070 align:start position:0% could be a secondary way to measure observations<00:52:18.400> made<00:52:18.760> by<00:52:18.960> other<00:52:19.200> instruments 00:52:20.070 --> 00:52:20.080 align:start position:0% observations made by other instruments 00:52:20.080 --> 00:52:23.310 align:start position:0% observations made by other instruments like<00:52:20.240> the<00:52:20.360> Webb<00:52:20.560> Telescope<00:52:21.320> or<00:52:21.480> Hubble. 00:52:23.310 --> 00:52:23.320 align:start position:0% like the Webb Telescope or Hubble. 00:52:23.320 --> 00:52:25.270 align:start position:0% like the Webb Telescope or Hubble. In<00:52:23.381> [music]<00:52:23.440> time,<00:52:24.120> this<00:52:24.400> revolutionary 00:52:25.270 --> 00:52:25.280 align:start position:0% In [music] time, this revolutionary 00:52:25.280 --> 00:52:27.230 align:start position:0% In [music] time, this revolutionary field<00:52:25.800> should<00:52:26.160> allow<00:52:26.440> us<00:52:26.560> to<00:52:26.680> understand<00:52:27.160> the 00:52:27.230 --> 00:52:27.240 align:start position:0% field should allow us to understand the 00:52:27.240 --> 00:52:30.670 align:start position:0% field should allow us to understand the nature<00:52:27.720> of<00:52:27.880> our<00:52:28.080> universe,<00:52:29.160> its<00:52:29.360> history,<00:52:30.400> and 00:52:30.670 --> 00:52:30.680 align:start position:0% nature of our universe, its history, and 00:52:30.680 --> 00:52:32.550 align:start position:0% nature of our universe, its history, and even<00:52:31.000> its<00:52:31.200> future. 00:52:32.550 --> 00:52:32.560 align:start position:0% even its future. 00:52:32.560 --> 00:52:34.110 align:start position:0% even its future. I<00:52:32.640> hope<00:52:32.960> you<00:52:33.040> found<00:52:33.280> this<00:52:33.480> episode<00:52:33.960> as 00:52:34.110 --> 00:52:34.120 align:start position:0% I hope you found this episode as 00:52:34.120 --> 00:52:37.990 align:start position:0% I hope you found this episode as fascinating<00:52:34.840> as<00:52:35.040> I<00:52:35.160> have. 00:52:37.990 --> 00:52:38.000 align:start position:0% 00:52:38.000 --> 00:52:40.870 align:start position:0% >> This<00:52:38.280> video<00:52:38.720> by<00:52:38.880> Dan<00:52:39.240> Burns<00:52:39.680> explains<00:52:40.240> gravity 00:52:40.870 --> 00:52:40.880 align:start position:0% >> This video by Dan Burns explains gravity 00:52:40.880 --> 00:52:43.870 align:start position:0% >> This video by Dan Burns explains gravity in<00:52:41.000> a<00:52:41.080> visual<00:52:41.640> way<00:52:42.080> that's<00:52:42.400> really<00:52:42.840> elegant. 00:52:43.870 --> 00:52:43.880 align:start position:0% in a visual way that's really elegant. 00:52:43.880 --> 00:52:45.390 align:start position:0% in a visual way that's really elegant. What<00:52:44.040> do<00:52:44.160> you<00:52:44.400> think<00:52:44.600> is<00:52:44.680> going<00:52:44.880> to<00:52:44.960> happen<00:52:45.280> to 00:52:45.390 --> 00:52:45.400 align:start position:0% What do you think is going to happen to 00:52:45.400 --> 00:52:47.470 align:start position:0% What do you think is going to happen to the<00:52:45.480> balls<00:52:45.880> when<00:52:46.040> the<00:52:46.120> teacher<00:52:46.400> drops<00:52:46.760> them? 00:52:47.470 --> 00:52:47.480 align:start position:0% the balls when the teacher drops them? 00:52:47.480 --> 00:52:49.350 align:start position:0% the balls when the teacher drops them? As<00:52:47.600> soon<00:52:47.760> as<00:52:47.880> he<00:52:47.960> lets<00:52:48.200> them<00:52:48.360> go,<00:52:48.800> they<00:52:48.920> start 00:52:49.350 --> 00:52:49.360 align:start position:0% As soon as he lets them go, they start 00:52:49.360 --> 00:52:51.430 align:start position:0% As soon as he lets them go, they start orbiting<00:52:49.840> around<00:52:50.200> the<00:52:50.280> heavy<00:52:50.640> object<00:52:51.160> that<00:52:51.280> is 00:52:51.430 --> 00:52:51.440 align:start position:0% orbiting around the heavy object that is 00:52:51.440 --> 00:52:54.030 align:start position:0% orbiting around the heavy object that is pressing<00:52:51.960> down<00:52:52.320> on<00:52:52.440> the<00:52:52.560> 2D<00:52:53.000> plane. 00:52:54.030 --> 00:52:54.040 align:start position:0% pressing down on the 2D plane. 00:52:54.040 --> 00:52:56.470 align:start position:0% pressing down on the 2D plane. This<00:52:54.240> 2D<00:52:54.560> plane<00:52:54.880> represents<00:52:55.360> space-time,<00:52:56.320> and 00:52:56.470 --> 00:52:56.480 align:start position:0% This 2D plane represents space-time, and 00:52:56.480 --> 00:52:58.750 align:start position:0% This 2D plane represents space-time, and the<00:52:56.560> heavy<00:52:56.920> object<00:52:57.360> symbolizes<00:52:58.040> a<00:52:58.120> massive 00:52:58.750 --> 00:52:58.760 align:start position:0% the heavy object symbolizes a massive 00:52:58.760 --> 00:53:01.590 align:start position:0% the heavy object symbolizes a massive object<00:52:59.360> warping<00:52:59.880> space-time.<00:53:00.880> Or<00:53:01.120> in<00:53:01.240> basic 00:53:01.590 --> 00:53:01.600 align:start position:0% object warping space-time. Or in basic 00:53:01.600 --> 00:53:04.270 align:start position:0% object warping space-time. Or in basic terms,<00:53:02.280> it<00:53:02.360> creates<00:53:02.720> gravity.<00:53:03.720> This<00:53:03.920> mimics 00:53:04.270 --> 00:53:04.280 align:start position:0% terms, it creates gravity. This mimics 00:53:04.280 --> 00:53:06.950 align:start position:0% terms, it creates gravity. This mimics gravity<00:53:04.800> in<00:53:05.040> our<00:53:05.200> solar<00:53:05.520> system<00:53:05.960> really<00:53:06.240> well. 00:53:06.950 --> 00:53:06.960 align:start position:0% gravity in our solar system really well. 00:53:06.960 --> 00:53:09.030 align:start position:0% gravity in our solar system really well. You<00:53:07.080> can<00:53:07.200> imagine<00:53:07.600> these<00:53:07.840> balls<00:53:08.280> as<00:53:08.520> objects 00:53:09.030 --> 00:53:09.040 align:start position:0% You can imagine these balls as objects 00:53:09.040 --> 00:53:11.550 align:start position:0% You can imagine these balls as objects or<00:53:09.160> planets<00:53:09.680> orbiting<00:53:10.080> our<00:53:10.240> sun.<00:53:11.080> Although, 00:53:11.550 --> 00:53:11.560 align:start position:0% or planets orbiting our sun. Although, 00:53:11.560 --> 00:53:13.310 align:start position:0% or planets orbiting our sun. Although, the<00:53:11.720> difference<00:53:12.160> in<00:53:12.280> the<00:53:12.360> solar<00:53:12.640> system<00:53:13.160> is 00:53:13.310 --> 00:53:13.320 align:start position:0% the difference in the solar system is 00:53:13.320 --> 00:53:15.270 align:start position:0% the difference in the solar system is that<00:53:13.520> there<00:53:13.640> is<00:53:13.760> no<00:53:13.920> friction<00:53:14.360> in<00:53:14.480> space.<00:53:15.160> They 00:53:15.270 --> 00:53:15.280 align:start position:0% that there is no friction in space. They 00:53:15.280 --> 00:53:16.870 align:start position:0% that there is no friction in space. They don't<00:53:15.480> lose<00:53:15.680> energy,<00:53:16.200> so<00:53:16.400> they<00:53:16.520> keep 00:53:16.870 --> 00:53:16.880 align:start position:0% don't lose energy, so they keep 00:53:16.880 --> 00:53:18.390 align:start position:0% don't lose energy, so they keep orbiting. 00:53:18.390 --> 00:53:18.400 align:start position:0% orbiting. 00:53:18.400 --> 00:53:20.990 align:start position:0% orbiting. While<00:53:18.680> this<00:53:18.880> is<00:53:19.040> a<00:53:19.080> simulation<00:53:19.720> of<00:53:19.880> 2D<00:53:20.240> space 00:53:20.990 --> 00:53:21.000 align:start position:0% While this is a simulation of 2D space 00:53:21.000 --> 00:53:23.030 align:start position:0% While this is a simulation of 2D space with<00:53:21.360> objects<00:53:21.920> circling<00:53:22.440> at<00:53:22.560> the<00:53:22.680> edges 00:53:23.030 --> 00:53:23.040 align:start position:0% with objects circling at the edges 00:53:23.040 --> 00:53:25.510 align:start position:0% with objects circling at the edges moving<00:53:23.400> in<00:53:23.600> towards<00:53:23.960> the<00:53:24.040> center,<00:53:24.960> in<00:53:25.080> 3D 00:53:25.510 --> 00:53:25.520 align:start position:0% moving in towards the center, in 3D 00:53:25.520 --> 00:53:27.470 align:start position:0% moving in towards the center, in 3D space,<00:53:26.240> objects<00:53:26.640> move<00:53:26.840> in<00:53:27.000> towards<00:53:27.360> the 00:53:27.470 --> 00:53:27.480 align:start position:0% space, objects move in towards the 00:53:27.480 --> 00:53:29.950 align:start position:0% space, objects move in towards the center<00:53:27.840> from<00:53:28.160> all<00:53:28.360> directions,<00:53:29.320> above<00:53:29.760> and 00:53:29.950 --> 00:53:29.960 align:start position:0% center from all directions, above and 00:53:29.960 --> 00:53:32.550 align:start position:0% center from all directions, above and below,<00:53:30.520> as<00:53:30.720> well<00:53:30.920> as<00:53:31.040> the<00:53:31.160> sides.<00:53:32.040> But<00:53:32.200> why<00:53:32.360> do 00:53:32.550 --> 00:53:32.560 align:start position:0% below, as well as the sides. But why do 00:53:32.560 --> 00:53:34.790 align:start position:0% below, as well as the sides. But why do objects<00:53:32.920> in<00:53:33.080> our<00:53:33.280> solar<00:53:33.600> system<00:53:34.120> only<00:53:34.440> orbit 00:53:34.790 --> 00:53:34.800 align:start position:0% objects in our solar system only orbit 00:53:34.800 --> 00:53:36.990 align:start position:0% objects in our solar system only orbit in<00:53:35.080> one<00:53:35.360> direction?<00:53:36.320> Check<00:53:36.600> out<00:53:36.720> the<00:53:36.800> pinned 00:53:36.990 --> 00:53:37.000 align:start position:0% in one direction? Check out the pinned 00:53:37.000 --> 00:53:39.470 align:start position:0% in one direction? Check out the pinned comment<00:53:37.360> for<00:53:37.520> more.<00:53:38.040> Gravity<00:53:38.560> can<00:53:38.720> pack<00:53:39.080> a<00:53:39.160> bit 00:53:39.470 --> 00:53:39.480 align:start position:0% comment for more. Gravity can pack a bit 00:53:39.480 --> 00:53:41.990 align:start position:0% comment for more. Gravity can pack a bit of<00:53:39.560> a<00:53:39.640> punch,<00:53:40.440> but<00:53:40.560> did<00:53:40.720> you<00:53:40.800> know<00:53:41.120> gravity<00:53:41.840> is 00:53:41.990 --> 00:53:42.000 align:start position:0% of a punch, but did you know gravity is 00:53:42.000 --> 00:53:43.870 align:start position:0% of a punch, but did you know gravity is not<00:53:42.360> tied<00:53:42.640> directly<00:53:43.200> to<00:53:43.320> the<00:53:43.400> size<00:53:43.680> of<00:53:43.800> the 00:53:43.870 --> 00:53:43.880 align:start position:0% not tied directly to the size of the 00:53:43.880 --> 00:53:45.910 align:start position:0% not tied directly to the size of the planet<00:53:44.200> causing<00:53:44.560> it?<00:53:45.240> Take<00:53:45.400> a<00:53:45.480> look<00:53:45.680> at<00:53:45.760> this 00:53:45.910 --> 00:53:45.920 align:start position:0% planet causing it? Take a look at this 00:53:45.920 --> 00:53:47.870 align:start position:0% planet causing it? Take a look at this simulation<00:53:46.520> of<00:53:46.640> a<00:53:46.720> weight<00:53:47.000> falling<00:53:47.320> on<00:53:47.440> a<00:53:47.520> car 00:53:47.870 --> 00:53:47.880 align:start position:0% simulation of a weight falling on a car 00:53:47.880 --> 00:53:49.470 align:start position:0% simulation of a weight falling on a car on<00:53:48.000> different<00:53:48.320> planets<00:53:48.720> and<00:53:48.800> moons<00:53:49.200> to<00:53:49.320> see 00:53:49.470 --> 00:53:49.480 align:start position:0% on different planets and moons to see 00:53:49.480 --> 00:53:51.950 align:start position:0% on different planets and moons to see what<00:53:49.680> I<00:53:49.720> mean.<00:53:50.560> Smaller<00:53:51.040> celestial<00:53:51.520> bodies 00:53:51.950 --> 00:53:51.960 align:start position:0% what I mean. Smaller celestial bodies 00:53:51.960 --> 00:53:54.030 align:start position:0% what I mean. Smaller celestial bodies like<00:53:52.200> the<00:53:52.320> moon<00:53:52.680> or<00:53:52.800> Pluto<00:53:53.240> have<00:53:53.480> less<00:53:53.680> gravity 00:53:54.030 --> 00:53:54.040 align:start position:0% like the moon or Pluto have less gravity 00:53:54.040 --> 00:53:55.950 align:start position:0% like the moon or Pluto have less gravity than<00:53:54.240> Earth,<00:53:54.800> causing<00:53:55.160> the<00:53:55.240> same<00:53:55.480> mass<00:53:55.840> to 00:53:55.950 --> 00:53:55.960 align:start position:0% than Earth, causing the same mass to 00:53:55.960 --> 00:53:57.910 align:start position:0% than Earth, causing the same mass to bounce<00:53:56.280> off<00:53:56.480> the<00:53:56.600> simulation<00:53:57.160> car<00:53:57.440> with<00:53:57.640> much 00:53:57.910 --> 00:53:57.920 align:start position:0% bounce off the simulation car with much 00:53:57.920 --> 00:54:00.510 align:start position:0% bounce off the simulation car with much less<00:53:58.080> damage.<00:53:58.920> Gravity<00:53:59.320> on<00:53:59.440> the<00:53:59.520> moon<00:53:59.800> is<00:53:59.960> 1/6 00:54:00.510 --> 00:54:00.520 align:start position:0% less damage. Gravity on the moon is 1/6 00:54:00.520 --> 00:54:02.670 align:start position:0% less damage. Gravity on the moon is 1/6 as<00:54:00.680> powerful<00:54:01.160> as<00:54:01.280> on<00:54:01.440> Earth,<00:54:02.040> and<00:54:02.200> gravity<00:54:02.560> on 00:54:02.670 --> 00:54:02.680 align:start position:0% as powerful as on Earth, and gravity on 00:54:02.680 --> 00:54:05.990 align:start position:0% as powerful as on Earth, and gravity on Pluto<00:54:03.160> is<00:54:03.360> only<00:54:03.600> 1/15<00:54:04.480> as<00:54:04.600> powerful.<00:54:05.600> However, 00:54:05.990 --> 00:54:06.000 align:start position:0% Pluto is only 1/15 as powerful. However, 00:54:06.000 --> 00:54:07.550 align:start position:0% Pluto is only 1/15 as powerful. However, it's<00:54:06.160> not<00:54:06.360> a<00:54:06.440> planet's<00:54:06.920> size<00:54:07.240> that<00:54:07.400> really 00:54:07.550 --> 00:54:07.560 align:start position:0% it's not a planet's size that really 00:54:07.560 --> 00:54:09.670 align:start position:0% it's not a planet's size that really matters,<00:54:08.240> but<00:54:08.360> it's<00:54:08.520> density. 00:54:09.670 --> 00:54:09.680 align:start position:0% matters, but it's density. 00:54:09.680 --> 00:54:11.830 align:start position:0% matters, but it's density. Although<00:54:10.000> Uranus<00:54:10.400> has<00:54:10.560> a<00:54:10.640> radius<00:54:11.080> four<00:54:11.440> times 00:54:11.830 --> 00:54:11.840 align:start position:0% Although Uranus has a radius four times 00:54:11.840 --> 00:54:13.590 align:start position:0% Although Uranus has a radius four times larger<00:54:12.080> than<00:54:12.240> Earth,<00:54:12.760> its<00:54:12.920> gravity<00:54:13.280> is<00:54:13.400> only 00:54:13.590 --> 00:54:13.600 align:start position:0% larger than Earth, its gravity is only 00:54:13.600 --> 00:54:16.230 align:start position:0% larger than Earth, its gravity is only 90%<00:54:14.320> of<00:54:14.440> ours.<00:54:15.160> This<00:54:15.320> is<00:54:15.440> because<00:54:15.920> the<00:54:16.000> gas 00:54:16.230 --> 00:54:16.240 align:start position:0% 90% of ours. This is because the gas 00:54:16.240 --> 00:54:17.950 align:start position:0% 90% of ours. This is because the gas that<00:54:16.360> makes<00:54:16.560> it<00:54:16.680> up<00:54:16.920> is<00:54:17.040> not<00:54:17.280> very<00:54:17.480> dense, 00:54:17.950 --> 00:54:17.960 align:start position:0% that makes it up is not very dense, 00:54:17.960 --> 00:54:20.030 align:start position:0% that makes it up is not very dense, making<00:54:18.240> this<00:54:18.400> impact<00:54:18.800> comparable. 00:54:20.030 --> 00:54:20.040 align:start position:0% making this impact comparable. 00:54:20.040 --> 00:54:21.830 align:start position:0% making this impact comparable. The<00:54:20.080> same<00:54:20.320> is<00:54:20.440> even<00:54:20.720> more<00:54:20.920> true<00:54:21.200> of<00:54:21.360> Saturn 00:54:21.830 --> 00:54:21.840 align:start position:0% The same is even more true of Saturn 00:54:21.840 --> 00:54:24.710 align:start position:0% The same is even more true of Saturn with<00:54:22.040> nine<00:54:22.360> times<00:54:22.720> our<00:54:22.880> radius,<00:54:23.400> but<00:54:23.640> 1.08 00:54:24.710 --> 00:54:24.720 align:start position:0% with nine times our radius, but 1.08 00:54:24.720 --> 00:54:26.230 align:start position:0% with nine times our radius, but 1.08 times<00:54:25.000> our<00:54:25.080> gravity. 00:54:26.230 --> 00:54:26.240 align:start position:0% times our gravity. 00:54:26.240 --> 00:54:28.230 align:start position:0% times our gravity. With<00:54:26.440> enough<00:54:26.840> mass,<00:54:27.200> even<00:54:27.440> low<00:54:27.600> density<00:54:28.080> is 00:54:28.230 --> 00:54:28.240 align:start position:0% With enough mass, even low density is 00:54:28.240 --> 00:54:31.310 align:start position:0% With enough mass, even low density is overcome.<00:54:29.160> Jupiter's<00:54:29.600> gravity<00:54:30.040> is<00:54:30.240> 2.4<00:54:31.000> times 00:54:31.310 --> 00:54:31.320 align:start position:0% overcome. Jupiter's gravity is 2.4 times 00:54:31.320 --> 00:54:33.070 align:start position:0% overcome. Jupiter's gravity is 2.4 times that<00:54:31.480> of<00:54:31.600> Earth's,<00:54:32.280> and<00:54:32.400> as<00:54:32.520> for<00:54:32.640> the<00:54:32.720> gravity 00:54:33.070 --> 00:54:33.080 align:start position:0% that of Earth's, and as for the gravity 00:54:33.080 --> 00:54:37.150 align:start position:0% that of Earth's, and as for the gravity of<00:54:33.160> the<00:54:33.280> Sun<00:54:33.880> at<00:54:34.040> 27.9<00:54:35.040> times,<00:54:35.680> it's<00:54:35.880> no<00:54:36.120> joke. 00:54:37.150 --> 00:54:37.160 align:start position:0% of the Sun at 27.9 times, it's no joke. 00:54:37.160 --> 00:54:39.190 align:start position:0% of the Sun at 27.9 times, it's no joke. The<00:54:37.280> results<00:54:37.680> of<00:54:37.800> this<00:54:38.040> simple<00:54:38.440> experiment 00:54:39.190 --> 00:54:39.200 align:start position:0% The results of this simple experiment 00:54:39.200 --> 00:54:40.710 align:start position:0% The results of this simple experiment may<00:54:39.400> surprise<00:54:39.920> you. 00:54:40.710 --> 00:54:40.720 align:start position:0% may surprise you. 00:54:40.720 --> 00:54:42.430 align:start position:0% may surprise you. We<00:54:40.840> have<00:54:41.040> here<00:54:41.280> two<00:54:41.600> different<00:54:41.960> ramps<00:54:42.320> that 00:54:42.430 --> 00:54:42.440 align:start position:0% We have here two different ramps that 00:54:42.440 --> 00:54:44.630 align:start position:0% We have here two different ramps that the<00:54:42.520> metal<00:54:42.800> ball<00:54:43.080> can<00:54:43.280> roll<00:54:43.480> down.<00:54:44.280> The<00:54:44.400> one<00:54:44.560> on 00:54:44.630 --> 00:54:44.640 align:start position:0% the metal ball can roll down. The one on 00:54:44.640 --> 00:54:46.470 align:start position:0% the metal ball can roll down. The one on the<00:54:44.720> right<00:54:45.000> is<00:54:45.160> smooth<00:54:45.520> and<00:54:45.640> uniform,<00:54:46.320> while 00:54:46.470 --> 00:54:46.480 align:start position:0% the right is smooth and uniform, while 00:54:46.480 --> 00:54:48.670 align:start position:0% the right is smooth and uniform, while the<00:54:46.600> one<00:54:46.840> on<00:54:46.920> the<00:54:47.040> left<00:54:47.320> is<00:54:47.480> bumpy<00:54:48.120> with<00:54:48.360> dips 00:54:48.670 --> 00:54:48.680 align:start position:0% the one on the left is bumpy with dips 00:54:48.680 --> 00:54:49.990 align:start position:0% the one on the left is bumpy with dips and<00:54:48.840> rises. 00:54:49.990 --> 00:54:50.000 align:start position:0% and rises. 00:54:50.000 --> 00:54:51.870 align:start position:0% and rises. In<00:54:50.120> a<00:54:50.160> moment,<00:54:50.640> Professor<00:54:51.080> Kelly<00:54:51.360> will<00:54:51.600> roll 00:54:51.870 --> 00:54:51.880 align:start position:0% In a moment, Professor Kelly will roll 00:54:51.880 --> 00:54:53.670 align:start position:0% In a moment, Professor Kelly will roll two<00:54:52.080> balls<00:54:52.480> down<00:54:52.800> each<00:54:53.000> ramp<00:54:53.280> at<00:54:53.360> the<00:54:53.440> same 00:54:53.670 --> 00:54:53.680 align:start position:0% two balls down each ramp at the same 00:54:53.680 --> 00:54:54.790 align:start position:0% two balls down each ramp at the same time. 00:54:54.790 --> 00:54:54.800 align:start position:0% time. 00:54:54.800 --> 00:54:56.710 align:start position:0% time. What<00:54:54.920> do<00:54:55.000> you<00:54:55.080> think<00:54:55.280> will<00:54:55.440> happen? 00:54:56.710 --> 00:54:56.720 align:start position:0% What do you think will happen? 00:54:56.720 --> 00:54:58.590 align:start position:0% What do you think will happen? Both<00:54:56.960> balls<00:54:57.280> are<00:54:57.320> the<00:54:57.440> same<00:54:57.720> weight,<00:54:58.240> and 00:54:58.590 --> 00:54:58.600 align:start position:0% Both balls are the same weight, and 00:54:58.600 --> 00:55:00.270 align:start position:0% Both balls are the same weight, and there<00:54:58.800> are<00:54:58.880> no<00:54:59.040> tricks<00:54:59.360> involved<00:54:59.960> such<00:55:00.160> as 00:55:00.270 --> 00:55:00.280 align:start position:0% there are no tricks involved such as 00:55:00.280 --> 00:55:01.390 align:start position:0% there are no tricks involved such as magnets.<00:55:00.583> [music] 00:55:01.390 --> 00:55:01.400 align:start position:0% magnets. [music] 00:55:01.400 --> 00:55:04.190 align:start position:0% magnets. [music] This<00:55:01.640> is<00:55:01.880> pure<00:55:02.280> physics<00:55:02.760> in<00:55:02.920> action. 00:55:04.190 --> 00:55:04.200 align:start position:0% This is pure physics in action. 00:55:04.200 --> 00:55:06.190 align:start position:0% This is pure physics in action. If<00:55:04.360> you're<00:55:04.560> like<00:55:04.800> me,<00:55:05.240> you<00:55:05.360> might<00:55:05.520> expect<00:55:05.920> both 00:55:06.190 --> 00:55:06.200 align:start position:0% If you're like me, you might expect both 00:55:06.200 --> 00:55:07.590 align:start position:0% If you're like me, you might expect both balls<00:55:06.480> to<00:55:06.600> reach<00:55:06.800> the<00:55:06.880> bottom<00:55:07.200> at<00:55:07.280> the<00:55:07.320> same 00:55:07.590 --> 00:55:07.600 align:start position:0% balls to reach the bottom at the same 00:55:07.600 --> 00:55:10.470 align:start position:0% balls to reach the bottom at the same time,<00:55:08.440> but<00:55:08.640> this<00:55:08.880> doesn't<00:55:09.280> occur. 00:55:10.470 --> 00:55:10.480 align:start position:0% time, but this doesn't occur. 00:55:10.480 --> 00:55:12.590 align:start position:0% time, but this doesn't occur. The<00:55:10.560> professor<00:55:11.040> uses<00:55:11.360> a<00:55:11.400> pencil<00:55:11.840> to<00:55:11.960> drop<00:55:12.280> both 00:55:12.590 --> 00:55:12.600 align:start position:0% The professor uses a pencil to drop both 00:55:12.600 --> 00:55:14.630 align:start position:0% The professor uses a pencil to drop both balls<00:55:12.920> at<00:55:13.040> once. 00:55:14.630 --> 00:55:14.640 align:start position:0% balls at once. 00:55:14.640 --> 00:55:16.590 align:start position:0% balls at once. And<00:55:14.800> there<00:55:14.920> you<00:55:15.040> have<00:55:15.240> it.<00:55:16.000> Although<00:55:16.280> both 00:55:16.590 --> 00:55:16.600 align:start position:0% And there you have it. Although both 00:55:16.600 --> 00:55:18.590 align:start position:0% And there you have it. Although both balls<00:55:16.920> went<00:55:17.040> the<00:55:17.120> same<00:55:17.360> distance<00:55:17.800> down,<00:55:18.520> the 00:55:18.590 --> 00:55:18.600 align:start position:0% balls went the same distance down, the 00:55:18.600 --> 00:55:20.190 align:start position:0% balls went the same distance down, the dips<00:55:18.880> provided<00:55:19.400> the<00:55:19.480> left<00:55:19.760> ball<00:55:19.960> with<00:55:20.120> a 00:55:20.190 --> 00:55:20.200 align:start position:0% dips provided the left ball with a 00:55:20.200 --> 00:55:22.030 align:start position:0% dips provided the left ball with a greater<00:55:20.520> chance<00:55:20.840> to<00:55:20.960> accelerate<00:55:21.680> without 00:55:22.030 --> 00:55:22.040 align:start position:0% greater chance to accelerate without 00:55:22.040 --> 00:55:24.190 align:start position:0% greater chance to accelerate without friction<00:55:22.520> putting<00:55:22.800> the<00:55:22.880> brakes<00:55:23.280> on.<00:55:24.040> This 00:55:24.190 --> 00:55:24.200 align:start position:0% friction putting the brakes on. This 00:55:24.200 --> 00:55:26.350 align:start position:0% friction putting the brakes on. This gave<00:55:24.440> the<00:55:24.520> ball<00:55:24.800> enough<00:55:25.080> momentum<00:55:25.880> to<00:55:26.000> speed 00:55:26.350 --> 00:55:26.360 align:start position:0% gave the ball enough momentum to speed 00:55:26.360 --> 00:55:28.190 align:start position:0% gave the ball enough momentum to speed ahead<00:55:26.720> of<00:55:26.800> the<00:55:26.880> ball<00:55:27.160> on<00:55:27.240> its<00:55:27.400> right,<00:55:27.920> even 00:55:28.190 --> 00:55:28.200 align:start position:0% ahead of the ball on its right, even 00:55:28.200 --> 00:55:30.150 align:start position:0% ahead of the ball on its right, even when<00:55:28.360> it<00:55:28.480> hit<00:55:28.600> the<00:55:28.720> bumps<00:55:29.000> on<00:55:29.120> its<00:55:29.280> journey. 00:55:30.150 --> 00:55:30.160 align:start position:0% when it hit the bumps on its journey. 00:55:30.160 --> 00:55:32.150 align:start position:0% when it hit the bumps on its journey. When<00:55:30.280> it<00:55:30.400> comes<00:55:30.640> to<00:55:30.760> speed,<00:55:31.440> momentum<00:55:31.960> is<00:55:32.080> a 00:55:32.150 --> 00:55:32.160 align:start position:0% When it comes to speed, momentum is a 00:55:32.160 --> 00:55:35.230 align:start position:0% When it comes to speed, momentum is a powerful<00:55:32.600> thing. 00:55:35.230 --> 00:55:35.240 align:start position:0% 00:55:35.240 --> 00:55:37.030 align:start position:0% You<00:55:35.360> may<00:55:35.520> have<00:55:35.640> noticed<00:55:36.080> this<00:55:36.280> video<00:55:36.640> didn't 00:55:37.030 --> 00:55:37.040 align:start position:0% You may have noticed this video didn't 00:55:37.040 --> 00:55:39.510 align:start position:0% You may have noticed this video didn't have<00:55:37.360> any<00:55:37.560> sponsors<00:55:38.640> and<00:55:38.760> that's<00:55:38.960> because<00:55:39.400> it 00:55:39.510 --> 00:55:39.520 align:start position:0% have any sponsors and that's because it 00:55:39.520 --> 00:55:41.790 align:start position:0% have any sponsors and that's because it was<00:55:39.680> brought<00:55:40.040> to<00:55:40.160> you<00:55:40.440> by<00:55:40.720> our<00:55:41.040> astronauts<00:55:41.640> on 00:55:41.790 --> 00:55:41.800 align:start position:0% was brought to you by our astronauts on 00:55:41.800 --> 00:55:42.910 align:start position:0% was brought to you by our astronauts on patreon. 00:55:42.910 --> 00:55:42.920 align:start position:0% patreon. 00:55:42.920 --> 00:55:44.750 align:start position:0% patreon. Consider<00:55:43.280> joining<00:55:43.720> our<00:55:43.840> patreon<00:55:44.360> to<00:55:44.480> keep 00:55:44.750 --> 00:55:44.760 align:start position:0% Consider joining our patreon to keep 00:55:44.760 --> 00:55:46.750 align:start position:0% Consider joining our patreon to keep these<00:55:44.960> videos<00:55:45.320> thriving<00:55:46.000> even<00:55:46.440> when<00:55:46.600> they're 00:55:46.750 --> 00:55:46.760 align:start position:0% these videos thriving even when they're 00:55:46.760 --> 00:55:48.950 align:start position:0% these videos thriving even when they're sponsor<00:55:47.120> free.<00:55:48.000> It's<00:55:48.200> the<00:55:48.280> reason<00:55:48.640> we<00:55:48.760> can 00:55:48.950 --> 00:55:48.960 align:start position:0% sponsor free. It's the reason we can 00:55:48.960 --> 00:55:51.350 align:start position:0% sponsor free. It's the reason we can research<00:55:49.480> deep<00:55:49.920> into<00:55:50.120> the<00:55:50.240> topics<00:55:50.600> we<00:55:50.720> love 00:55:51.350 --> 00:55:51.360 align:start position:0% research deep into the topics we love 00:55:51.360 --> 00:55:53.150 align:start position:0% research deep into the topics we love without<00:55:51.680> cutting<00:55:52.000> corners<00:55:52.520> or<00:55:52.720> chasing 00:55:53.150 --> 00:55:53.160 align:start position:0% without cutting corners or chasing 00:55:53.160 --> 00:55:54.190 align:start position:0% without cutting corners or chasing clicks. 00:55:54.190 --> 00:55:54.200 align:start position:0% clicks. 00:55:54.200 --> 00:55:56.630 align:start position:0% clicks. Every<00:55:54.560> new<00:55:54.760> astronaut<00:55:55.520> allows<00:55:55.880> us<00:55:56.040> to<00:55:56.160> explore 00:55:56.630 --> 00:55:56.640 align:start position:0% Every new astronaut allows us to explore 00:55:56.640 --> 00:55:59.750 align:start position:0% Every new astronaut allows us to explore bigger<00:55:57.040> ideas<00:55:58.000> and<00:55:58.240> make<00:55:58.520> every<00:55:58.800> upload<00:55:59.440> even 00:55:59.750 --> 00:55:59.760 align:start position:0% bigger ideas and make every upload even 00:55:59.760 --> 00:56:02.310 align:start position:0% bigger ideas and make every upload even better<00:56:00.040> than<00:56:00.240> the<00:56:00.320> last.<00:56:01.360> So<00:56:01.600> if<00:56:01.840> you've<00:56:02.120> ever 00:56:02.310 --> 00:56:02.320 align:start position:0% better than the last. So if you've ever 00:56:02.320 --> 00:56:03.710 align:start position:0% better than the last. So if you've ever thought<00:56:02.640> about<00:56:02.840> being<00:56:03.080> a<00:56:03.160> bigger<00:56:03.400> part<00:56:03.680> of 00:56:03.710 --> 00:56:03.720 align:start position:0% thought about being a bigger part of 00:56:03.720 --> 00:56:05.990 align:start position:0% thought about being a bigger part of this<00:56:03.920> channel,<00:56:04.600> join<00:56:04.920> the<00:56:05.000> crew<00:56:05.480> to<00:56:05.640> power 00:56:05.990 --> 00:56:06.000 align:start position:0% this channel, join the crew to power 00:56:06.000 --> 00:56:11.120 align:start position:0% this channel, join the crew to power Astrum<00:56:06.800> and<00:56:06.960> keep<00:56:07.320> space<00:56:07.840> curiosity<00:56:08.560> alive.