life.
As of yet, there is only one example we
know of the life we find here on Earth.
There is no definitive proof of life
anywhere else in the universe. But that
does not mean for certain that it's not
out there. If there is alien life on
planets other than our own, what might
they look like? What would be their
biology? and what would we see of their
civilization?
You might think there is no way to
predict this. However, believe it or
not, even though we have never seen a
single alien, we can make educated
guesses based in science to help us know
what to expect. And it's all thanks to a
simple principle. Form follows function.
I'm Alex Mccoan and you're watching
Astramm. And although we cannot say with
exact certainty what any aliens visiting
us might appear like or how they behave
culturally and technologically, today
I'm going to share with you some ideas
that might mean if they ever do land on
our doorstep, you aren't completely
caught off guard.
But first, let's talk about why we look
the way we do.
As you look down at your own body, even
if you do not know what all of it does,
you are an incredible example of
optimization.
You likely have two hands complete with
fingers and opposable thumbs, ideal for
grasping tools, and performing fiddly,
delicate operations.
You have a digestive system that is
capable of taking in matter, extracting
nutrients, and using them to build up or
repair yourself. You have legs for
locomotion,
a brain for thinking, a heart that will
on average pump 2.5 billion times across
your lifetime without breaking. All of
these parts of your body perform
specific functions and have been honed
over millennia to be really good at what
they do, even if you don't feel it
sometimes. You are an example of form
following function. Thanks to natural
selection and random mutation, nature is
really good at figuring out what works.
When Charles Darwin was voyaging through
the Galapagus Islands, he noticed that
different finches had different shaped
beaks. After observing them for a time,
Darwin noticed that the finches with
larger, more heavy set beaks ate
different types of food than finches
with smaller, daintier beaks. In fact, a
large beak was ideally suited to
breaking open tough seeds or nuts, while
the smaller beaks were more suited to
getting in nooks and crannies for
grabbing insects. This observation was
the basis for his well-known theory of
evolution. In this theory, thanks to
genetic variation and competition,
nature is constantly trying out new
things to see what works. And there are
certain things that give you an edge.
Thanks to all the light that was
bouncing around from our sun, organisms
that evolved to take advantage of this
by developing sight had a bigger
advantage over organisms that did not.
They could find food better or avoid
predators or generally navigate their
environment.
So useful is site that nature did not
just come up with it once. We believe
the eye evolved independently about 40
times over the course of life on Earth.
40 different species that previously
could not see evolved eyes.
This is called convergent evolution. And
eyes are not the only example of it
happening. Bats are not related to birds
and yet both developed wings to fly. And
speaking of bats, both bats and dolphins
independently evolved echolocation to
help them see in environments where
light was not so plentiful.
Photosynthesis has arisen dozens of
times.
Koalas have almost identical
fingerprints to humans. This happens
because there are some selective
pressures that are simply universal.
Everything that lives needs to gain
nutrients, grow, and reproduce. And as a
result, like a plant bending its roots
around rocks to find softer soil, nature
is good at figuring out the best way of
getting what it needs. Because of the
prevalence of light, eyes are just a
good idea. And when something works,
nature sometimes comes up with it more
than once. This means that on planets
that are similar to our own, it's
entirely possible that evolution would
end up going a similar way.
Although hypothetical aliens on other
planets might not look exactly like us,
they might look surprisingly similar. I
always thought that it looks silly that
so many aliens in sci-fi films were
humanoid. But perhaps this is more than
just a way of easing pressure on the
film's costume department. Convergent
evolution says this might actually
happen. If it worked for us, maybe it
just works generally. Any alien that
made it to the stars would need to have
the ability to work tools. So, fingers
or something similar would be a likely
addition to an alien race. Large heads
filled with complex brains for analysis
and problem solving would also be a
benefit.
The human brain is the most complex of
any animals on Earth with 86 billion
neurons. It's not so unreasonable that
aliens would be the same. Thanks to our
brains, it became less important to keep
ourselves warm with fur, as we could
craft clothes for ourselves. So, aliens
may not be hairy or thick-skinned if
they are intelligent.
Of course, this kind of logic might not
carry all the way because life might not
arise on a planet that's exactly the
same as ours. If there are different
selective pressures, different
adaptations might occur. For instance,
on a planet with low gravity, plants and
animals would be able to grow much
taller than on Earth. There would be
less energy cost to lifting nutrients up
through their bodies or pumping blood
around if aliens use those kind of
systems. While conversely, on a planet
with very high gravity, you'd likely see
stockier, shorter, heavier built aliens.
Their bones would need to be denser to
support them in heavier gravity. or
possibly they would be aquatic as
gravity is less of a problem in water.
On a planet that is further out from its
star than ours, there would be less
light, so an alien's eyes might be
bigger. Or maybe aliens on such planets
would rely on things like echolocation
to see what is around them. On planets
with elliptical orbits, seasonal
temperatures would vary much more
wildly. Perhaps on such planets, you'd
see an increase in the ability to
hibernate or even come back from near
death, such as tardigrades and their
incredible ability to return to
animation after being in the harshest of
environments like the depths of space.
Temperature can also affect size. Such
as in the depths of our oceans, there
occurs deep sea gigantism. As large
bodies can more efficiently be kept
warm, while in deserts, small animals
have a larger mass to surface area
ratio, allowing them to disperse heat
more effectively.
On a planet with fewer magnetic fields,
more bombarded by cosmic radiation,
perhaps life would have shorter
lifespans in much the same way as around
the heavily irradiated Chernobyl nuclear
power plant.
Dogs and other short-lived organisms
thrive while longerived humans suffer.
In each case, form follows function.
Life will adapt to suit the conditions
it finds itself in. And it doesn't end
there.
Did you know that this logic can apply
to cultures and civilizations too? When
the Spanish conquistadors met the
Aztecs, there was a significant
technological gap in spite of both
groups being humans. Some historians
hypothesized that this can be linked to
things like the ease at which each group
could farm.
Intensive crops that require a lot of
effort to grow require more of the
population to spend their time farming,
leaving fewer individuals free for
invention and scientific pursuits. There
are likely many other factors at play,
too, but environment is certainly one of
them.
Prevalence of coal or other fuel sources
could spark an industrial revolution.
The presence or absence of silicon or
rare metals might help or hinder a
computer revolution, speeding up or
slowing down a civilization's progress.
Once an alien race has evolved to the
point where it has become intelligent,
unless it came into being through some
weird mechanism we don't understand, it
probably did so through out competing
its rivals and collecting resources for
itself and its offspring. Civilizations
made up of such creatures will most
likely also have a hunger for space and
resources. Whether they gain these
things through clever diplomacy or
aggression, it is most likely that they
will want them. Form follows function.
This quest for expansion and seeking
more and more energy and resources led
Soviet astrophysicist Nikolai Kardashev
in 1964 to propose the Kardashev scale
for classifying the different kinds of
alien civilizations that might exist out
there. He grouped civilizations into
three kinds. Type one civilizations can
completely utilize the energy available
on their planet. We have not quite
reached this point as a species, so we
are roughly a 0.6 7 on Cardesev scale.
Type two completely utilized the energy
available from their star, possibly by
building a giant mega structure such as
a Dyson sphere to capture and utilize
all of its energy output. Type 3
civilizations would be able to utilize
the entire energy output of its galaxy.
We have seen no evidence of an alien
civilization such as this one, which is
for the best, as they would likely see
us in the same way we see bacteria.
Mildly interesting, but otherwise
completely beneath their notice.
Other scientists since card have
proposed further additions to this
scale. Type fours that use all the
energy in the universe. Type fives that
use all the energy in multiple
universes. Or even the enigmatic type
omega capable of utilizing energy
sources beyond even that perhaps
existing outside of time entirely.
Such a civilization would essentially be
gods. We would have no way of detecting
them because nothing in the universe
would exist except in the way they
wanted it to. and we would have nothing
to compare their existence against.
While this may seem like a bleak outlook
for humanity, if we ever came across
another alien race, under this theory,
we would almost certainly end up
competing for resources in one way or
another or just getting steamrolled by a
vastly higher power. There are actually
other possibilities for alien
development, too. After all, not all
humans are interested in expanding ever
outwards. In fact, with the advent of
internet and online cyberspace, more and
more human interaction is taking place
in virtual spaces. Carl Sean proposed a
model that classifies alien races based
on how many unique pieces of information
they collectively know. Although much
harder for us to detect at a distance,
and admittedly hard to measure, this way
of gauging advancement does not require
an alien race to infinitely expand. An
intelligent race that started looking
internally or even one that spent its
entire conscious time in some kind of
cyberspace could still learn more and
more about itself and the universe as a
whole while taking less and less space
within that universe. For the record,
Carl Sean's scale is alphabetic where we
were at about a type J civilization as
apparently we knew 10 ^ 13 bits of
unique information in 1973.
While I haven't been able to find out
exactly how he worked out that figure
and mention in the comments if you know
we are probably further along this scale
now 50 years on. But as a comparison a
type zed civilization would need to know
10 ^ 31 bits more information than
exists in the whole universe. So it's
unlikely that such a race exists at
least not yet. Ultimately, we do not
know for sure. Alien life continues to
remain elusive. And while it's true that
we have not met an alien civilization,
it is comforting to know that is
entirely plausible there would be
something about them that we could
understand or even find relatable. Form
follows function. We as humans are the
beings that think and gain mastery of
our world. Perhaps one day we will meet
another race that does the same things
we do. Rather than seeing something
truly alien, it perhaps will be like
looking into a mirror. I'll leave it to
you to decide whether that is a
comforting thought or not.
Intelligent life is an extremely
unlikely certainty. It is unlikely
because the number of things that have
to go right before it can occur is truly
mind-boggling. And yet it is a certainty
because it did occur right here on Earth
with you and me. And once an event has
occurred, the odds of that occurrence
become 100% no matter how unlikely it
seemed to begin with. As near as we can
tell, this was quite unusual. As we look
out across the universe, we think we see
desolate lifeless planet after desolate
lifeless planet.
Still, given the sheer number of planets
that exist, how likely is it that
intelligent life sprang up not once, but
twice or even more times?
Are we alone in the universe? What are
the probabilities?
I'm Alex Mccoan and you're watching
Astramm. Today, we shall have a stab in
the dark at solving these mysteries and
see what we hit.
To begin with though, let's start with a
caveat. If we're going to try to figure
out what the odds are of intelligent
life existing in the universe, we should
ask ourselves the question, what do we
mean by life?
Life on planet Earth comes in many
shapes and sizes. From the tallest trees
to the smallest microbes, from spindly
insects to birds or fish or humans, our
planet is teeming with life.
We generally understand what we mean
when we say a living thing. We might
define it by it moving around or by it
growing. Generally speaking, scientists
define life as any system that is
capable of eating, metabolizing,
excreting, breathing, moving, growing,
reproducing, and responding to external
stimuli. Essentially, they are aware of
their surroundings in some way. They
seek resources.
They take those resources into
themselves and they use them to grow or
create more of themselves and then they
get rid of any waste that's left over.
Ew.
Some forms of life are much more active
than others. But even things like plants
can move to face the sun, open their
buds, or spread out their roots over
time. So we look at these things and
consider them living.
Even on Earth though, there are some
systems like viruses that push the
boundary of what it means to be a living
thing. Viruses are so simple that they
lack the ability to reproduce by
themselves or to metabolize.
Instead, they get cells they infect to
do that work for them. Are viruses
alive? They certainly have proved
devastating to other populations of
living things, and we can definitely
think of them that way. But it's a
debate that still rages on in the
scientific community. So although there
are certain qualities that are fairly
universal for living things here on
Earth, we must be careful about how we
go about defining life. For instance,
most living things on Earth make use of
water to function. It carries important
nutrients around our bodies and is so
vital for all life on Earth that we
consider the absence of water to be a
serious red flag if another planet
doesn't have it. But if an alien was
somehow able to exist by pumping liquid
methane through its body instead of
water, would that stop it from being a
living thing? Probably not.
So let's keep an open mind, but roughly
let's define life as those things that
seek out resources, grow and reproduce.
Whether those creatures are
predominantly water like us, or whether
they are made from some other elements
or even pure energy, it doesn't really
matter. All we care about is the
likelihood of them reaching a level of
intelligence where they might be able to
talk to us. To get to that level, there
are still a number of things that need
to go right. To begin with, they would
most likely need a star to orbit. As
near as we can tell, life cannot exist
without energy. They would need a planet
that suited them. They would need to
compete with other organisms for limited
resources, thus encouraging them to
adapt and progress. In time, they would
need to develop problem-solving skills
and intelligence as a way of gaining
those resources and outco competing
their rivals.
Their civilization would then have to
survive without accidentally becoming
extinct due to a freak meteor strike or
earthquake or global freezing.
They would also have to not destroy
themselves.
They would have to invest in technology
and would have to develop a level of
technology that allowed them to reach
out across the universe. They'd also
have to have a desire to talk to any
potential neighbors as opposed to being
intensely isolationist
and finally would have to broadcast a
signal out to us for long enough that we
would be able to spot them. All of this
is by no means certain. However, as was
pointed out by astronomer and
astrophysicist Frank Drake in the first
SETI meetings in 1961, all of this could
be used to calculate the probability of
us finding alien life. He laid all this
out in his famous Drake equation.
This may look a little complicated, but
it's based on a very clever and logical
idea. using the same logic that says you
can figure out how many students are in
a school by calculating how many
students were inducted into the school
at the start of each year and then
multiplying that by the number of years
students studied for. Drake reasoned
that the way of calculating the number
of civilizations in our galaxy whose
electromagnetic emissions are detectable
could be calculated provided you knew
the rates at which those other steps
happened. Let's break it down. N is the
number we're looking for. How many alien
races are out there for us to see or
hear? This will give us an idea of the
odds of finding them.
A star is the rate of formation of stars
suitable for the development of
intelligent life in number per year. Not
all stars are very suitable for life to
develop as some are too cold or too hot
or generally too unstable.
We need to know how many are being born
that could support life.
FP is the fraction of those stars with
planets. Ne is the number of those
planets per solar system with
atmospheres and material compositions
suitable for life. If they're covered
with lava or are completely devoid of
atmosphere or water, it's unlikely that
life could form there based on our own
planet's example.
L is the fraction of how many of those
planets that could support life actually
do support life.
FI is the fraction of planets for which
that life becomes intelligent.
FC is the fraction of times that life
advances enough technologically to start
sending out signals of their existence.
And finally, L is the length of time a
civilization exists on average. If you
combine all of these elements, you could
accurately predict how many alien
civilizations we would be able to see up
in our sky right now. Of course, you
might have noticed a drawback with this
equation. Some of these numbers are
simply not known by us. But where's the
fun in not giving it a go? Anyway, by
inputting the numbers that scientists
currently believe to be most likely, and
by making a few assumptions of my own
along the way, we will attempt to solve
the Drake equation. If you think that
any of my numbers seem unreasonable, let
me know in the comments below.
So with that, let's see how many alien
civilizations we might reasonably expect
to see out in the night sky. To begin
with, we can input our values with
reasonable certainty. Scientists looking
at the Milky Way galaxy can accurately
predict how many stars form every year
as we have many examples to draw from.
Depending on who you ask, the number
ranges from between three and seven.
Let's say five at a conservative
estimate.
FP is easy to solve, too. Through recent
astronomical observations by the Kepler
Space Telescope, it's become apparent
that planets are very common in the
solar system, with each star on average
having one. So, let's set this number
high as well, let's say 90%.
However, the number that we currently
predict is at a suitable distance from
their stars, as well as having the ideal
mix of elements that would produce life
similar to ours is much lower. Of the
100 billion planets in the solar system,
perhaps as few as 300 million fit into
this category. Obviously, this does not
account for alien life that's
significantly different from us, but
let's discount them for the moment, as
then this would be even harder to
predict. This gives us a percentage
chance of 0.3%.
Quite a small chance that one of the
planets in a solar system is suitable
for life. So 0.003
for NE.
So far so substantiated by evidence.
Here is where things get a little
tricky. For the number of times that
life has arisen, we only have one
example to draw from. Life on Earth. To
date, we have not proved that life arose
on Mars or Ganymede for all the
conjecture on that front. So, we can
take this estimate one of two ways. As
near as we can tell from the fossil
record, as soon as the planet cooled
down enough, life came into being, which
might indicate a high value for F,
perhaps as high as a certainty one. But
on the other hand, from what we know,
all life originated from a common
ancestor, which is to say, life formed
on this planet from non-biological
matter exactly once and has never risen
up again since.
Scientists have looked for evidence of
bacteria that might have independently
come into being, but so far haven't
found any. This may be a coincidence.
Perhaps life did arise multiple times,
but the life that arose first was more
advanced and so out competed the newly
formed simple bacteria into extinction.
Still, it means that life is either
incredibly certain or a million to one.
Let's go with the more pessimistic
number and see where that takes us. L
equals 0.00001%.
We encounter the same problem for the
arising of intelligence. There are
numerous examples of animals displaying
forms of intelligence. Octopi can open
jars and solve puzzles, and some birds
and apes can use tools or even use sign
language. Perhaps this proves that given
enough time, life always evolves into
becoming more intelligent.
However, if we want to be strict about
it, we could also accurately say that of
all the millions of species that have
existed on the Earth, only one was
intelligent enough for our purposes. us,
which makes the odds seem very low for
it happening. Let's once again input our
1 million to one value for FI again just
to be pessimistic.
In terms of how many become
technologically advanced enough to start
communicating, I think this number is
likely much higher. Although we only
have one species to compare to again,
it's worth noting that humans are
unintentionally chatty with the universe
quite by accident. Thanks to industry
and transport, we are altering the
chemical composition of our atmosphere,
which is something an alien race could
detect. Certain molecules in our
atmosphere are only there because they
are man-made.
We also send signals out into space
thanks to our radio signals and
satellites.
Sometimes we even send signals out into
the stars deliberately, such as the
Arosibo message, which was broadcast
from Earth in 1974 and contained
information about human civilization and
history, expressly so any aliens that
heard it could learn about us.
Although these signals would not travel
far on the grand cosmological scale of
things before becoming dispersed and
indistinguishable from background
radiation, we would count as a
communicating race. So I'm going to
predict this number as high. Let's say
70% of intelligent races reach this
level.
Finally, how long do civilizations
survive for this number? Sadly, we do
not even have a single example. We do
not know how long our race will survive
until we die out, by which point there
will be no one left to write down the
final figure. However, although there
are numerous dangers that could end us
as a species, ranging from meteor
strikes, nuclear war, or even solar
flares, the longer we are able to
survive, the more likely it is that we
will go on surviving. This is because
once humanity spreads out, we become
more and more resilient to a species
threatening catastrophe. If we are on
multiple planets, a comet hitting Earth
would no longer threaten the survival of
our species. If we are in multiple solar
systems, a solar flare would no longer
be able to get all of us.
Species could in theory reach a sort of
immortality level in this way, lasting
for potentially billions of years as
long as they could get out of the danger
range. Let's be optimistic and use this
figure. What does that give us for the
Drake equation? Based on these
assumptions, our answer is zero in our
galaxy.
If civilizations live for trillions of
years, which is longer than the universe
has existed for, we'd still be at zero
for these values. Given these odds, our
chances of ever hearing from another
civilization is next to non-existent.
But that's just the thing with this kind
of estimate. If we instead assumed that
life arising was certain and that
intelligence arising was certain, too,
our final answer for even a 1,000-year
civilization would no longer be zero.
Instead, that comes to an answer of nine
in our galaxy. Nine intelligent races
who might be up in the stars right now
trying to communicate with us. And if
races routinely do make it to functional
immortality to the point where their
civilizations last for billions of
years, then we would see as many as
9,450,000
in our galaxy or more.
I know these are hypotheticals, but I
find this very interesting. Putting the
numbers through the equation makes it a
bit more tangible, a bit more magical
and exciting even. According to the
Drake equation, the sky could be
completely silent or absolutely teeming
with alien life. If it is the former,
then we should probably prepare
ourselves for a long, lonely existence.
We should learn to get along with each
other because we are all the life we are
ever going to see. There will be no
aliens stopping by to say hello. But if
it is the latter, it leads to a very
important question. Where are they all?
But that is a question we will have to
look at in the next video of this
series. For now, my own biggest takeaway
from this is that we need to try to
refine some of these numbers. Through
the efforts of rovers like Perseverance
on Mars, we are already taking steps
towards attempting to find alien life
within our own solar system. The more we
are able to narrow these numbers down,
the more certain we will be as to our
odds of finding alien civilizations.
Until we find one, it's all a question
of odds and whether the chances are high
or low. Well, that's very much up to
you. So, write in the comments what do
you think or what would you rather?
Throughout human history, much thought
has gone into what alien life might look
like. Sometimes they are depicted as
grayskinned humanoids with large eyes,
sometimes as strange tentacle monsters.
But ultimately, while this is an
interesting question to consider, it's
not really the most important one. For
there is a far more pressing
consideration we need to talk about if
aliens actually do exist. Namely, if we
encounter aliens tomorrow, what might we
expect them to do?
While this may seem like an idle
question, our survival as a species
might depend on us knowing the answer.
Because if aliens do exist, by the time
they find us, it will be too late to
consider it. By then, it might be too
late to do anything at all. This is a
question that determines our species
destruction or maybe our salvation.
I'm Alex Mccoan and you're watching
Astramm. Join with me today as we see
what we should do when approaching the
search for alien life. Because depending
on the answer to this question, we have
some vitally significant choices ahead
of us as a species. And seeing as this
is a question that scientists and
political leaders are not yet
considering seriously, let's have a go
at it on this platform. For this video,
I will draw on some of the ideas and
knowledge we've explored so far in the
other videos in this series. So, if you
haven't seen them, then you might want
to check them out using the link above.
If our speculations on the behavior of
hypothetical aliens are to be useful to
us, they need to be grounded in real
observations as much as possible. For
instance, we know that life can arise in
the universe because it did at least
once with us. We know that we can see no
signs of any other alien life, an idea
we have considered with the Fermy
paradox. So any behavior we look at has
to line up with this fact. And we have
considered how when species evolve, form
follows function. The same evolutionary
imperatives that drive us likely would
drive other species, too. In all
probability, everyone needs to eat or
reproduce in one way or another, or they
would likely all die out. So although we
don't know for certain that alien life
is even out there, let's bring these
ideas together. In doing so, we gain
some revealing insights. To begin with,
though, let's hold up the mirror to
ourselves.
We are the only instance of life arising
in the universe that we know of. The
great human experiment of civilization
has been going on for thousands of years
and has produced many different types of
society. Capitalist, socialist, hunter
gatherer, nomadic, and theocratical to
name just a few. If we want to
understand the behavior of alien
civilizations, we need to consider
societies. We thus have quite a few
ideas to compare when considering how
aliens might behave. Broadly speaking
though, let's examine two great extremes
and see how they might influence alien
civilization. These two extremes are
altruism and aggression, love and
violence. Let's start with violence.
that while this may be a pessimistic
starting point, it is sadly one we must
consider because as human civilization
has developed throughout eras, different
groups of humans have almost always
clashed violently. This ties into the
evolutionary idea that competition
always occurs when there are more
organisms than there are resources.
Humans are organisms and we need
resources to survive. And so all too
often war throughout the ages has been
fought over resources,
agricultural land, people, and all the
labor power and industry they can
produce, gold, oil. Even when a
civilization develops space travel and
reaches for the stars, this issue will
still likely exist. After all, we are
nearly at the stars ourselves, and there
certainly seems to be no shortage of
violent conflict amongst us today.
So with a sample size of exactly one, we
have to at least consider the
possibility that the other alien races
are the same as us, driven by a need for
resources to support an ever growing
population.
Of course, when it comes to societies,
there are even more reasons why clashes
might occur. For instance, religious or
ideological differences. The Cold War
was largely fought between countries
that espoused different political
ideologies. capitalism and communism
that threatened each other. Alien
civilization might equally differ from
us ideologically. In fact, it would be
surprising if they didn't. And so, it's
possible they might feel their ideology
is threatened in some way by ours. This
could lead to conflict, too.
This is not even to mention the fact
that some cultures idolize violence
itself, deeming themselves of worth only
when they are winning victories, such as
Viking raiders or Spartan hoplights.
Others seek to build empires,
recognizing it's much easier to take
wealth from others than it is to build
it yourself.
All these reasons are perfectly
plausible for an intelligent race that
has mastered its planet, outco competed
other life forms there, and likely feels
good about doing so. Survival feels
good. We enjoy feeling strong.
But if this leads to conflict, what
might an alien conflict look like?
Technology raises the stakes. We
currently lack the technology to move
objects to other solar systems. Given
the vast distances throughout space,
unless we intend to just throw insulting
messages at each other through the void,
actual fighting cannot be achieved until
we manage to solve speed of light travel
and probably something faster than that.
It is possible that one day we might get
around this problem and this instantly
opens a dangerous possibility.
It is theoretically impossible to move
something up to the speed of light
because of the link between mass and
energy. The more energy something has,
the more mass it has because the two are
linked and thus the more energy you need
to increase its speed further. This is
only noticeable at relativistic speeds,
but it does mean you'd need infinite
energy to move mass up to the speed of
light. But if you throw an asteroidsized
object at a planet at near light speed,
then all that energy gets released in
one go. This kind of strike can easily
wipe out all life on a planet and the
people on it wouldn't even see it
coming.
Any intelligent race would be very aware
of the impact potential of objects such
as this. For us, we only need to look at
the dinosaurs. You don't need nukes or
soldiers on the ground to fight an alien
war. Just rocks thrown really, really
fast.
This opens up one possible answer to the
Fermy paradox. If alien civilizations
exist and any of them proved to be
willing to do this, maybe the other
aliens realized that it was simply safer
not to communicate. Letting other races
know that you are there would simply
place a target on your back. After all,
if you could both do this and they
wouldn't see it coming, could they
really trust you not to strike first?
They could see us as a risk that they
are not willing to take.
Known as the dark forest theory, this
possible answer to the Fermy paradox
says that the only aliens out there are
silent simply because they don't wish to
be on the possible receiving end of
these kind of planet buster weapons.
Like hunters traveling cautiously
through a dark forest, they are all
either quiet or dead. They have been
subject to this selective pressure.
However, this is not the only plausible
model of behavior that might still
prevent us from seeing aliens. The
second option is simply indifference.
With billions of years of history at
play, it might not be the case that we
are on technological par with all the
other forms of life that might be out
there. Alien life might simply be so far
beyond us, they simply regard us as
dispassionately as we might an ant. They
might not be talking to us because we
have nothing interesting to say. Why do
you not talk to insects in your garden?
The gap is too great. You understand
what they want perfectly and they have
no hope of understanding you.
Communication would be frankly
pointless.
That said, life might be rare in the
universe. If they desire resources and
are that far beyond us, they probably
wouldn't need to mine our planet
specifically. We might have value as a
curiosity, something to be left alone to
flourish simply because they have
decided that we have some value as a
specimen in some kind of grand cosmic
zoo. And as any zookeeper would tell
you, the closer you get an enclosure to
look like an animal's natural habitat,
the happier that animal normally is.
While they might not care about us,
perhaps they do not wish to alarm us by
stepping into our natural habitat. In
fairness, this is a valid line of
reasoning. Humanity would likely find it
very distressing to learn that we are in
fact not at the top of the food chain
and that our very existence depends on
the mild indifference of a vastly
superior alien race.
Of course, if this was true, we would
need to be careful. In my home, I was
perfectly willing to live and let live
when I found ants in my garden. When
ants came into my kitchen, I quickly got
out the ant killer. We would do well not
to provoke them. Both of these ideas
about alien behavior are bleak. So,
you'll be glad to know that there is one
alternative to hatred and indifference.
And in fact, it may prove to be the most
realistic for higher levels of society.
Cooperation.
Cooperation exists within nature. Not
all life competes. Within species, packs
of wolves can cooperate to achieve their
goals, protecting those within the
group, even as they attack those outside
it. There are giant super colonies of
ants that do this, working together and
spanning entire countries, with each
hill all considering themselves as part
of the same colony. Aggressive to those
outside of it, but supportive and even
self-sacrificing towards those within.
There are advantages to this as we
humans are well aware. We would not have
gotten anywhere if we hadn't learned how
to work together. Knowledge pulled
allows the creation of all kinds of
technology.
Ironically, no one really knows how to
build a computer from scratch, but there
are people who know how to build a
motherboard, other people who know how
to build a screen, and other people that
know how to mine the resources. And all
these people know that the other people
exist. and so can work together.
Historically speaking, there is
compelling evidence that as time has
gone on, we humans have become better at
this kind of cooperative thinking, too.
It used to be that groups of humans were
localized into small tribes fighting
other small tribes. However, that
elevated to small kingdoms, then big
ones, then whole countries and alliances
spanning across national borders.
Following that to its natural
conclusion, at some point a nation may
exist that all humans in the world feel
a part of a unified planet Earth.
But why is this a more likely outcome
than violence? Simply put, technology
forces it. Not only do we remove
barriers to communication the more
advanced our communication gets, but as
our ability to destroy ourselves
increases, there simply isn't an
alternative except learning how to get
along other than total annihilation, of
course. But that's a pretty unappealing
alternative, one would hope. And so,
it's possible that aliens develop the
same way. If they did, how might they
behave towards the universe at large?
While they might still be aggressive to
outsiders initially, ultimately they may
have attempted to take this to the next
level, embracing new alien races as
brothers and sisters, part of a great
galactic whole. It's just a continuation
of the trend with potentially millions
of years of history drilling the dangers
of violence into them. They may actually
abhore fighting, and there may be
millions of aliens of many different
races all cooperating peacefully under
one banner. Then why don't we see them?
Well, perhaps they prefer to let us
learn our own historical lessons about
the value of cooperation before speaking
to us. An aggressive race would not
benefit the galactic community as a
whole. So, until we learn to get along,
advanced alien races might not want to
share with us their ideas and
technology, particularly if such toys
could then be used as weapons. Perhaps
they believe that we will either figure
out how to get along or else we'll wipe
ourselves out. Either way, in the
meantime, it is better they stay hands
off.
As any parent will tell you, sometimes
telling a child something is not enough
for a lesson to sink in. Sometimes
experience is the only effective
teacher. There might be a galactic
community out there just waiting to
welcome us.
violence, indifference, benevolence. In
theory, any of these or all of these in
some combination might be the reasons we
don't hear from alien life. Ultimately,
we would be wise to tread carefully.
Meeting alien civilizations might sound
exciting, but it would inevitably come
with terrible risks and possibly
fantastic rewards. Is it worth the
gamble?
Looking up to the stars on a bitingly
clear night, a horizon away from the
nearest town, you'll feel alone. But as
your eyes adjust, you are embraced by
the light of an entire universe,
surrounded by such scale and wonder.
It's hard in that moment to imagine that
we are it, isn't it? That we are the
only life the universe will ever know.
Confined as we are on this pale blue
dot.
Perhaps we are alone. Or maybe, just
maybe, given enough time, nature's laws
conspire to make life not just probable,
but inevitable.
I'm Alex Mccoan, and you're watching
Astramm. Join me today as we explore the
chaotic transition from chemistry to
biology on our planet, seeking answers
to some of the most debated and fervent
questions in science. What is life? How
could life have emerged on Earth in an
environment that would kill us as we are
today? And can it begin all over again
elsewhere in the universe or even on our
own planet?
To begin to answer those questions,
let's imagine that while walking across
a barren desert, your foot kicks a
stone. It wouldn't occur to you that
someone put it there or crafted it since
the stone is too simple an object. Now
imagine instead that you stumble across
a glistening precisionmade embossed gold
pocket watch. William Haley argued that
because unlike a stone, a watch
obviously requires a designer, you'd
have to assume that someone had made the
watch and placed it there. And because
when you truly think about it, life is
far more intricate than a watch. Life
too must require a designer. It's a
compelling argument, isn't it? Even the
simplest forms of life are far, far more
intricate than a watch. And if a watch
requires a designer, surely so must
life. Unfortunately, the argument
doesn't quite work. But why? What really
is the difference between a man-made
machine and mankind?
Charles Darwin's work on evolution and
the origin of species crystallize the
idea that life evolves and that all life
began from one common ancestor.
Therefore, I should infer from analogy
that probably all the organic beings
which ever have lived on this earth have
descended from some one primordial form
into which life was first breathed.
And there it is. Emergence. Life from
chemistry. Something different than the
sum of its parts. Darwin understood that
life needs no designer. It is able to be
more intricate than a watch without a
designer because it is a complex
adaptive system driven by natural
selection. It has the ability to evolve.
A watch is merely complicated.
But before we go back 4 billion years to
uncover life's genesis on Earth, we
should probably all agree on what it is
we're looking for. What do you think
defines life? What makes something
alive?
If you're struggling for an answer,
don't worry. Even NASA can't get three
words into their definition without
being challenged. This is science at the
bleeding edge.
NASA defines life as a self- sustaining
chemical system capable of Darwinian
evolution. Prominent scientists argue
that life is not strictly self-
sustaining. Life requires an environment
with which it has a dynamic relationship
where life draws its energy and raw
materials and expels its waste. An
environment that is full of free energy.
An environment that sustains life.
Life's relationship with its environment
is crucial to understanding how life is
possible. You see, life is at first
glance in defiance of the second law of
thermodynamics.
How does the beautiful design of a
bacterial cell with its incredible
complexity, control, and order seemingly
defy entropy and emerge out of a
structurous chemical soup? According to
the second law, entropy should always
increase and systems should get more
disordered with time, not less. It was
Irwin Shreddinger who realize that it is
the environment that picks up the
thermodynamic cost in his book, What is
Life? In 1944,
on closer inspection, when we include
the environment that sustains life,
entropy does increase overall. The
second law of thermodynamics is not
broken. In fact, entropy increases
faster with life than without. It is
this that led Jeremy England, a
professor at MIT, to say, "You start
with a random clump of atoms, and if you
shine a light on it for long enough, it
should not be so surprising that you get
a plant." Life is incredibly effective
at transforming energy and increasing
entropy. How effective? Let's compare it
to the brightest and most powerful
object in the solar system, the sun. In
just 58 micros secondsonds, it produces
more energy than our species has in its
entire history. Pound for pound though,
humans output a staggering 6,000 times
more power at rest than the sun. Despite
creating extremely localized order, life
degrades free energy to heat, increasing
entropy in the universe overall.
Unsurprisingly, given that you're
watching this video, it's clear that
entropy allows for or even encourages
the development of life. So, how did the
building blocks of life seemingly defy
entropy in constructing order from
chaos? How does a living cell build up
that can power itself, encode itself
with DNA, construct itself too, and have
the ability to evolve? And how can it do
it all piece by piece while being
functional at every step even though
each part is essential? How on earth
could life emerge?
Well, there is little consensus on the
precise way that life actually emerged
on Earth. But let's explore the
molecules that without exception build
every single life form on Earth. Perhaps
life offers clues to its own origin.
The key basic building blocks life uses
today in no particular order are fatty
acids, amino acids, and nucleotides. And
all three are believed to have been
present on the early Earth and have even
been found on asteroids in our solar
system.
The first are fatty acids and despite
having little chemical functionality,
they create structure and have an
extraordinary function built in. These
longchain molecules make up cell walls
of all life on Earth and are believed to
have made the first membranes of
protoells.
Membranes are barriers and fundamental
to create an individual unit. After all,
you can't have a house without walls or
a country without borders. That's not a
political statement. Remarkably,
cell-like structures made from fatty
acids form spontaneously in water. As
anyone who's failed to make a simple
mayonnaise will know all too well, oil
and water don't like to mix. These fatty
acids with a water loving head and a
water-hating tail will spontaneously
arrange to minimize water's contact with
the tail and maximize it with the head.
These simple pressures can create a
blayer membrane with a cavity for an
early cell to call home. This is called
a liposome.
Unbelievably, these liposomes can also
spontaneously divide and speed up
chemical reactions by encapsulating and
concentrating the molecules in a smaller
space. This is a perfect example how
unexpected lielike behaviors can emerge
out of the laws of quantum mechanics.
But won't these crude divisions just go
wrong and kill the cell more often than
not in a hot salty water? Well, yes,
there's a good chance. However, the
environment isn't a simple system. It's
impure. There are other molecules
floating around that can stabilize the
cell walls further like amino acids. A
diverse range of these building blocks
were present on early Earth and are even
present in our solar system. Today, life
uses 20 different amino acids to make
all the cellular machinery within us
like enzymes and ion channels as well as
larger structures like muscle and hair.
There is a miraculous relationship
between amino acids that make up
proteins and our next building blocks
nucleotides.
A relationship that is important in
helping us to understand how life's
informationational system may have
emerged.
The ability of life to create and store
information is achieved by nucleotides
which are present today in RNA and DNA.
RNA is believed to be involved in the
origin of life because short chains of
RNA serve another simpler purpose. They
can also catalyze some chemical
reactions which perhaps kickstarted
life's early chemistry. Nucleotides have
other functions too and feature in
several vitally important molecules like
ATP and ADP, the pair of molecules that
drive work in a cell. Acetyl co-enzyme A
and vitamin B12.
In fact, every living cell today relies
on what's known as the central dogma.
DNA is translated to RNA, which encodes
proteins. This is strong evidence that
all life on Earth can be traced back to
one life form, Luca, the last universal
common ancestor. The central dogma is a
highly evolved system that has
redundancy and error correcting built
in. But the ability of RNA to encode
proteins may have much simpler
beginnings. One that doesn't require
enzymes. One driven in part by the same
physical pressures as fatty acids
forming a cell-like structure. A
mechanism that could have introduced
information to proto cells. You see,
different RNA bases can encode specific
amino acids. This means that a random
string of RNA in early protoells could
have produced a nonrandom string of
amino acids which could have conferred
an advantage to the protoell containing
it. Perhaps the amino acid stabilized
the membrane and it would have been more
likely to survive and divide potentially
reproducing that information and passing
it on. So now we have a great primordial
soup of molecular potential. We have the
thermodynamic encouragement for life.
Self-dividing cell walls and short RNA
strands that could have encoded
functional amino acids. How can we get
past this primordial soup of small
molecules for life to emerge? Well, we
also need the one mechanism that is
crucial to all theories, selection.
Without selection pressures, in 14
billion years, molecular complexity
wouldn't have moved much past basic
molecules like these, let alone a
complex enzyme, because you'd be relying
on random processes with very low
probabilities.
Very much like shaking a bag of Lego
bricks together for a few years and
expecting a perfectly formed Death Star
to pop out. As the size of a molecule
grows, the space of possible
configurations grows absurdly quickly,
and the probability that even one
specific molecule can be made in a
useful quantity by chance, falls to near
zero. And that's just for one molecule,
let alone a gold pocket watch. The
creationists may have a point.
Incredibly though, research suggests
that the proposed chemical reactions on
early Earth were capable of a kind of
evolution way before they transitioned
to life. Some chemical reaction pathways
can produce molecules that catalyze the
pathway itself. These are known as
autocatalytic.
This catalysis increases the flow of
resources through one pathway
potentially away from a competing
pathway and therefore increases the
first success. When these pathways loop
around on themselves they are known as
autoc catalytic sets. These are nent
forms of metabolism.
Crucially these metabolisms are
spontaneous and can exist without the
need for evolved enzymes.
We have seen how the molecules present
on early Earth interact and produce
lifelike behaviors without the need for
the highly specialized cellular control.
Much of life's chemistry may indeed be
spontaneous. Metabolism, chemical
selection, division, information
transfer. But in order for life to
emerge and for all these processes to
come together, we need time. But
incredibly, not much time at all. The
Earth formed around 4.54 billion years
ago. The moon was created 4.5 billion
years ago. There were liquid oceans
around 4.4 billion years ago. And the
earliest life is present potentially as
early as 4.3 billion years ago. For
something regarded by many as unlikely,
it's curious. Don't you think that
almost as soon as it is given the
chance, life emerges? Maybe life is
inevitable.
At least it was on the early Earth
because Earth has a lot of free energy
and is in effect a giant battery.
Some 4 billion years ago, our ocean was
acidic and lacking in electrons. While
the molten mantle just below it was
alkaline and rich in electrons, a huge
chemical charge imbalance that has been
shown to be used to power chemical
reactions that are evolving towards
life. There is a consensus that
somewhere on this world where the inside
of the earth meets the outside where the
two ends of the battery meet there was a
spark of some sorts. There are deep sea
hydrothermal vents, gas- fil caves, hot
springs, evaporating pools, and volcanic
areas totally devoid of oxygen. All have
all the elements that we think are
required for life to emerge to harvest
this free energy source and all would
have killed us if we were able to travel
back in seconds.
It is proposed that Luca was a
methanogen originating at one location
like these, an organism that reacted
hydrogen with carbon dioxide to make
methane. That's partly why a form of
life evolving from scratch now is
considered to be impossible because of
the oxygen concentration. Add oxygen to
hydrogen and instead of life, you've got
rocket fuel.
We may never know for sure if a form of
life existed before our central dogma
ancestral line, but that's not to say
life hasn't emerged elsewhere in our
galaxy or even our solar system. Planets
have been found nearby in our galaxy
that are similar to Earth and could
replicate the conditions of the early
Earth. Our planet is not so special.
Given the thermodynamic pressure for the
emergence of life, it seems as though
life on another planet is an
inevitability.
There is volcanic activity on moons
orbiting Saturn and Jupiter, providing a
similar environment beneath the surface
to Earth, too, which is why scientists
are so interested in exploring the icy
moons orbiting our nearby planets.
Hydrogenrich volcanic plumes just like
those from our deep sea vents have been
observed erupting from the surface of
Saturn's moon and Celadus.
Despite the extreme speed with which
life appeared to emerge on Earth, the
time to go from single-sellled to
multi-elled was 1.5 billion years. It's
clearly a hard jump in complexity to
evolve communication and cooperation
between cells, let alone interplanetary
communication with alien life forms. So
although we haven't found signs of life
elsewhere yet, absence of evidence is
not evidence of absence.
With all this, looking up to the stars,
the way all these molecules work
together, it's hard to feel alone in the
universe. The early Earth seemed ideal
for life to emerge. But then, even if it
was less hospitable, there is always a
chance. As Dr. Ian Malcolm said in
Jurassic Park, "Life Earth finds a way."
You may have heard many news stories
about all the thousands of exoplanets
that have been discovered using the
Kepler telescope.
As of the 1st of July 2018, Kepler has
confirmed the existence of 3,797
planets in 2,841
star systems with 632 systems having
more than one planet. But are any of
these planets habitable? What are the
chances of life being found outside of
Earth? Are we alone in this universe? Or
can life be more prevalent than we
think? And if there is life, where can
it be found? I'm Alex Mccoan and you're
watching Astramm. And together we will
explore known exoplanets in the Milky
Way galaxy to see if any of them have
the potential to harbor life.
Now, we've not been able to actually
image exoplanets in any kind of detail.
In fact, this is the clearest real image
we have of an exoplanet taken by ESO's
very large telescope. Which may make you
question, if this is the best image of
an exoplanet we have, how can we
discover exoplanets? And how do we know
life could be on one? To answer the
first question, we have to look at how
Kepler worked. Kepler is a space probe
which constantly monitored about 150,000
stars in a fixed field of view using its
camera. The field of view focuses on a
patch of sky near the constellation
signis. This is what Kepler can see. The
data it collects is sent to Earth and
analyzed to see if any stars dim
periodically.
You see, the concept is if a star's
planet passes in front of Kepler's view,
the star will dim. If it dims, for
instance, once every 100 days, we can
confirm that it is a planet and it takes
100 days to orbit.
Kepler is really good at finding
exoplanets.
Before Kepler came into operation, these
were the exoplanets we knew about. As
you can see, most of them are many times
the size of Jupiter.
Since Kepler came into operation, we
have discovered and confirmed the
existence of thousands of exoplanets
with thousands more still unconfirmed.
Remember, these are planets which have
been discovered in only this patch of
sky. There is still a lot more out
there.
Kepler unfortunately is no longer
functioning how it used to as some of
the reaction wheels inside it are
broken.
However, the good news is that there is
a new exoplanet finding spacecraft
called TESS, which just came into
operation a couple of weeks ago, which
will cover an area in the sky 400 times
larger than the Kepler mission. It is
expected that during its mission, it
will be able to find more than 20,000
exoplanets.
In order to determine details about an
exoplanet, the distance from us to its
star needs to be worked out using
complicated maths.
For stars within 400 light years away
from us, we can use trigonometry and the
orbit of the Earth to create a
difference in angles.
Beyond that, there is no direct
measurement. So, the best current method
is by comparing a star's color spectrum
to its brightness. The color spectrum of
a star corresponds to what type of star
it is. Once the color spectrum is known,
scientists then know how bright the star
should be.
Comparing the apparent brightness or the
apparent magnitude to the actual
brightness, the absolute magnitude of
the star reveals how far away it is.
This method is proven as scientists have
done this test on stars that are within
400 lightyear and the results produce
similar distances in both tests. Once
the distance to the star has been
determined, the amount the star dims can
be used to see how big the planet is,
its distance from the star, and the
exoplanet's mass based on the orbit of
the exoplanet. Using other telescopes
like Hubble, ESO and eventually the
James Web and the WI first telescopes.
These exoplanets can be studied to find
out their composition particularly of
their atmospheres. The way this is done
is again from the spectra of the
exoplanet's light. To give you an
example of how this is done, imagine
white light shooting through a prism,
producing what is actually a blend of
colors spanning from violet to red.
Light from a star shooting through an
atmosphere produces a similar effect,
except certain bands of light are not
present. This indicates there is a
certain gas in the atmosphere that is
absorbing the light in that wavelength,
not allowing it to pass through. The
dips in this image shows what Earth's
spectrum looks like as sunlight passes
through the atmosphere.
The dips show that oxygen is present as
well as water vapor, carbon dioxide, and
methane. These gases all absorb the
sun's light at these wavelengths.
Looking at a section of wavelengths and
comparing them with other planets in the
solar system, sulfur compounds can
clearly be seen on Venus and methane on
Neptune is apparent.
This means that as we study exoplanets
in detail and determine their spectra,
we can search for atmospheres that
resemble our own. If it does, then the
chances are that it could be a habitable
world and also that it may already
harbor life. Inhabited planets could
have telltale signs of life like smog
and pollution which would be seen in the
planet spectrum.
So, have any exoplanets like these been
found? Well, out of the thousands of
exoplanets that have been discovered, 16
of them are thought to be rocky planets
and sit in the Goldilock zone or the
habitable zone of their respective
stars.
Let's just remind ourselves of the
ingredients needed for life as we know
it.
We believe that liquid water needs to be
present. Liquid water is essential
because biochemical reactions can take
place in water.
Water is also an excellent solvent that
easily dissolves and carries nutrients
and other compounds in and out of cells.
Life forms on Earth are made primarily
of water. In fact, our human bodies are
more than 60% water.
Life also needs sufficient protection
from cosmic and solar radiation which
can break down and damage cells. On
Earth, this protection comes from our
magnetic field.
There also needs to be essential
chemicals found in the ground on Earth
and an energy source which for us is the
sun.
So the Goldilock zone is where assuming
other conditions are right liquid water
could theoretically pool on the surface.
This zone is always different depending
on the parent star and how big and hot
it is.
Looking at our own solar system, Venus
might just be in the Goldilock zone as
well as Earth and Mars,
we already know that only one in three
planets in our own solar systems
Goldilock zone can have liquid water.
So, just being in the right place is not
always enough.
The type of star is also important. Our
star, although seemingly active on the
surface, is actually quite stable
compared to a lot of other types of
stars. The sun will likely be 10 billion
years old before it burns out.
On the other hand, the hottest types of
stars will only last for millions of
years in comparison. It is thought that
this is not enough time for life to form
around it. Certainly not animal life
that can communicate as we understand
it.
So, we have a lot of filters we can now
use to narrow down our search for
habitable worlds. Out of the original
3,797
confirmed planets, 16 are terrestrial
planets that orbit within the Goldilock
zone of their stars. However, the
habitable zone of some stars means the
planets are close enough to be tightly
locked, meaning only one face of the
planet sees its star.
This proximity to the star also means
the planet is exposed to a lot of solar
radiation, sometimes thousands of times
more than we are exposed to on Earth. In
other words, out of those 16, only four
are likely candidates to be Earthlike.
Although, it is worth mentioning that
exoplanets in systems like the Trappist
one system could still be habitable or
have life even if all the planets are
tightly locked. But the Trappist system
is worthy of its own video, so I won't
expand on it here.
These four exoplanets are Lighton B,
Kepler 62F, Kepler 186F, and Kepler
442B.
Realistically speaking though, we don't
know much about them other than their
size and mass. Our current technology
isn't accurate enough to determine the
composition of their atmospheres.
One of the James Webb Space Telescope's
missions is to study known exoplanets in
greater detail, which is exciting as in
combination with the finding power of
the test telescope I mentioned earlier,
this next decade could be full of
discoveries.
But by using the Kepler data as a fairly
decent sample size, can we estimate how
many habitable worlds there could be in
our galaxy alone? Ethan Seagull did a
very interesting article which I will
link to in the description where out of
those 150,000 stars the chances of
seeing anything at all using the transit
method is very small less than 1% for a
planet orbiting the distance of Mercury
let alone Neptune which has a 0.01%
chance of detection. This is due to the
way planets tend to all orbit along a
plane. And if it's not lined up, we
won't see anything.
Also, smaller planets are much harder to
detect. Look how hard it is to see an
Earth-sized planet compared to a
Jupiterized planet.
Taking all these things into account,
Ethan Seagull placed a low estimate of
6.4 4 billion planets in their stars
habitable zone in our galaxy, the Milky
Way.
This means at least one of them has to
have life, too, surely. Well, we really
don't know how prevalent life is at all.
And until we do some serious research
and improve our technology, we have no
way of knowing yet.
Some people claim that all factors
considered, the chances of humans being
able to develop and live on Earth was 10
to the power of 10,123
to1. In other words, extremely unlikely.
How many factors actually are needed to
be right for life to exist? Is it all
over the place or purely a freak
coincidence here? Building on what we
know already means the future is going
to be very exciting.
A massive thank you to our astronauts on
Patreon. This video had no sponsors, but
it was still made possible thanks to the
hundreds of members we have there. Link
is in the description to join our
growing community. Patreon is where
Astramm truly takes shape. A place for
people who love space, who want to see
these videos keep improving and reaching
more curious minds. Every new member
keeps the channel focused on what really
matters, making the complexity of space
available to everyone. If you enjoy what
we do, come join the Astramm community
today.