WEBVTT

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(Narrator)
To have any hope of finding alien life,

00:02:05.537 --> 00:02:07.408
we have to know what to look for.

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But where do we begin?

00:02:15.303 --> 00:02:19.380
How do we narrow down a
seemingly infinite set of possibilities?

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There's one thing we know for sure:

00:02:30.683 --> 00:02:33.357
nature will have to play by her own rules.

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No matter how strange alien life might be,

00:02:40.386 --> 00:02:43.826
it's going to be limited by the same
physical and chemical laws

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that we are.

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On top of this,

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each alien environment will further limit

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what kinds of lifeforms can evolve there.

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Despite these natural boundaries,
the possibilities

00:03:10.125 --> 00:03:12.196
are staggering to imagine.

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Trillions of planets,

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each a unique cauldron of chemicals

00:03:17.924 --> 00:03:20.640
undergoing their own complex evolution.

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To guide our thinking,

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this museum of alien life
will be divided into two exhibits:

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life as we know it,

NOTE Paragraph

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home to beings
with biochemistries like ours;

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and life as we don't know it,

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home to beings that challenge our concept

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of life itself.

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Before we venture too far into
the unknown,

00:03:57.103 --> 00:03:58.727
we have to ask ourselves:

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what if alien life

00:04:01.128 --> 00:04:03.108
is more like us than we think?

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If there's one feature that unites us

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with the other specimens in this museum,

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it's carbon.

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(Nick Lane)
Carbon is ubiquitous,

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it's one of the most common
elements in the universe,

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and it's very good at forming
large, stable molecules.

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(Narrator)
Carbon has the rare ability to form

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four-way bonds
with other elements,

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and to bind to itself

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in long, stable chains,

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enabling the formation of
huge complex molecules.

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This versatility makes carbon
the centerpiece

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in the molecular machinery of life.

00:05:03.260 --> 00:05:06.110
And the same carbon compounds
that we use

00:05:06.110 --> 00:05:07.876
have been found far from Earth,

00:05:08.546 --> 00:05:10.028
clinging to meteorites,

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and floating in far-off clouds

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of cosmic dust.

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The building blocks of life,

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drifting like snow through the universe.

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And if alien life has selected

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other carbon compounds for their
biochemistry,

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they will have plenty to choose from.

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Scientists recently identified

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over a million possible alternatives
to DNA—

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all carbon-based.

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If we ever discover

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other carbon-based lifeforms,

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we would be fundamentally related.

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They would be our cosmic brethren.

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But would they look anything like us?

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If they hail from Earth-like planets,

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we could share even more in common

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than just our biochemistry.

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(Jonathan Losos)
What would life be like on other planets,

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if it is evolved?

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Would it be like

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the world today here on Earth,

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or would it be completely different?

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There are those who argue that,

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from the argument of convergent evolution,

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if conditions on other planets are
similar to here,

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then we would see very similar life forms—

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animal- and plant-like organisms
that look very familiar.

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(Narrator)
On Earth, certain features like

00:07:14.206 --> 00:07:16.768
eyesight, echolocation, and flight

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have evolved multiple times independently

00:07:19.492 --> 00:07:20.797
in different species.

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This process of convergent evolution

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could extend to alien planets like Earth,

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where creatures face similar environmental
pressures.

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It's no guarantee,

00:07:37.170 --> 00:07:38.229
but there could be

00:07:38.229 --> 00:07:40.544
certain universalities of life.

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The greatest hits of evolution
on repeat across the universe.

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Each feature would be attuned
to its local environment.

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Dimly lit planets

00:08:04.185 --> 00:08:07.985
would produce huge eyes to suck in
extra light,

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like nocturnal mammals.

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(Jonathan Losos)
Some people have gone so far as to say

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that human-type organisms,

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humanoids,

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will occur on other planets.

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The existence of other

00:08:27.146 --> 00:08:30.025
humanlike organisms seems unlikely,

00:08:30.025 --> 00:08:32.604
given the long, convoluted
chain of events

00:08:32.604 --> 00:08:33.624
that produced us.

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But we can't rule it out.

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If just one in every
hundred trillion Earth-like planets

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produced a humanlike form,

00:08:46.324 --> 00:08:47.284
there could still be

00:08:47.284 --> 00:08:49.586
thousands of creatures like us out there.

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Convergent evolution

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is also rampant in plant life,

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and C₄ photosynthesis has arisen
independently

00:09:17.540 --> 00:09:19.424
over 40 times.

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Would alien plants look like ours

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or something else entirely?

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On Earth, plants appear green

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because they absorb the other wavelengths

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in the Sun's light spectrum.

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But stars come in many colors,

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and alien plants would evolve
different pigments

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to adapt to their sun's unique spectrum.

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Plants feeding off hotter stars

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could appear redder,

00:10:08.184 --> 00:10:10.126
by absorbing their energy-rich

00:10:10.126 --> 00:10:11.126
bluer light.

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Around dim red dwarf stars,

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vegetation could appear black,

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adapted to absorb

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all visible wavelengths of light.

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Earth itself

00:10:45.990 --> 00:10:47.853
may have once appeared purple,

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due a pigment called retinal

00:10:49.795 --> 00:10:52.126 line:1
that was an early precursor
to chlorophyll.

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Some think that
retinal's molecular simplicity

00:10:58.049 --> 00:11:00.682
could make it a more universal pigment.

00:11:03.680 --> 00:11:04.986
If so,

00:11:04.986 --> 00:11:06.629
we may find that purple

00:11:07.603 --> 00:11:09.507
is life's favorite color.

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But the color of alien vegetation

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is more than just a curiosity—

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it's chemical information

00:11:27.025 --> 00:11:29.347
that can be seen from lightyears away.

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Earth plants leave a signature "bump"

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in the light reflected off our planet.

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Finding a similar signal
from another world

00:11:42.529 --> 00:11:44.917
could point the way to alien vegetation.

00:11:50.256 --> 00:11:51.631
Perhaps this will be

00:11:51.631 --> 00:11:54.390
our first glimpse at alien life:

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a vibrant hue cast by a distant world.

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(Caleb Scharf)
What happens when you change

00:12:22.096 --> 00:12:23.295
the day length of a planet?

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What happens when you change

00:12:24.368 --> 00:12:25.545
the tilt of a planet?

00:12:25.545 --> 00:12:26.537
What happens when you change

00:12:26.537 --> 00:12:27.835
the shape of the orbit?

00:12:27.835 --> 00:12:29.126
What happens when you change

00:12:29.126 --> 00:12:30.521
the gravity of a planet?

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(Narrator)
Planets with long, elliptical orbits

00:12:37.148 --> 00:12:39.860
would see drastic seasons.

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There could be worlds

00:12:42.300 --> 00:12:45.458
that appear dead for thousands of years,

00:12:45.458 --> 00:12:47.581
then suddenly spring to life.

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Most of the rocky planets
discovered so far

00:13:05.058 --> 00:13:07.078
have been massive "super-Earths".

00:13:12.557 --> 00:13:15.960 line:1
How would life evolve on these worlds?

NOTE Paragraph

00:13:18.540 --> 00:13:19.566
In the seas,

00:13:19.566 --> 00:13:21.752
gravity may not matter much at all.

00:13:29.470 --> 00:13:30.670
(Unnamed)
A high-gravity planet

00:13:30.670 --> 00:13:32.192
isn't high-gravity all over.

00:13:33.590 --> 00:13:36.257
If you're in the sea
and that's where all life starts,

00:13:36.257 --> 00:13:37.690
there's very nearly no gravity

00:13:37.690 --> 00:13:40.505
'cause you're much the same density
as the stuff around you.

00:13:43.310 --> 00:13:45.637
It's when the animals come out on land,

00:13:45.637 --> 00:13:47.169
that they feel the gravity.

00:13:51.518 --> 00:13:53.570
(Narrator)
High g-forces would necessitate

00:13:53.570 --> 00:13:55.633
large bones and muscle mass

00:13:55.633 --> 00:13:57.546
in complex life on land.

00:13:59.748 --> 00:14:00.836
They would also demand

00:14:00.836 --> 00:14:03.209
a more robust circulatory system.

00:14:04.773 --> 00:14:06.520
And plant life could be stunted

00:14:06.520 --> 00:14:09.019
by the energy cost of carrying nutrients

00:14:09.019 --> 00:14:10.584
under stronger gravity.

00:14:17.168 --> 00:14:18.547
Low-gravity planets

00:14:18.547 --> 00:14:21.798
would more easily
lose their atmospheres to space,

00:14:21.798 --> 00:14:23.337
and lack a magnetic field

00:14:23.337 --> 00:14:25.443
to protect from cosmic rays.

00:14:35.751 --> 00:14:37.605
But smaller worlds could be home

00:14:37.605 --> 00:14:39.404
to secret oases:

00:14:46.161 --> 00:14:47.503
huge cave systems

00:14:47.503 --> 00:14:49.544
that provide hideouts for life.

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The smallest possible habitable planets

00:15:29.353 --> 00:15:31.897
are estimated at 2.5%

00:15:31.897 --> 00:15:33.312
Earth's mass.

00:15:35.002 --> 00:15:37.793
If surface life does evolve
on these worlds,

00:15:38.742 --> 00:15:40.627
it could be a sight to behold.

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Plant life could grow to towering heights,

00:15:47.394 --> 00:15:50.460
able to carry nutrients higher
in lesser gravity.

00:15:59.044 --> 00:16:00.160
And without the need

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for bulky skeletons and muscle mass,

00:16:02.754 --> 00:16:04.511
animals could have body types

00:16:04.511 --> 00:16:06.170
that boggle the mind.

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Here on Earth,

00:16:32.310 --> 00:16:34.835
it took three billion years for evolution

00:16:34.835 --> 00:16:37.404
to produce complex plant and animal life.

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Simpler organisms are hardier,

00:16:41.654 --> 00:16:42.716
more adaptable,

00:16:42.716 --> 00:16:44.213
and more widespread.

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The largest collection

00:16:49.705 --> 00:16:51.440
in the museum of alien life

00:16:51.440 --> 00:16:54.419
would likely be the "Hall of Microbes".

00:17:10.116 --> 00:17:12.960
Yet finding even the tiniest alien microbe

00:17:12.960 --> 00:17:15.200
would be a profound discovery.

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And bite-sized life

00:17:31.849 --> 00:17:33.616
could leave a big footprint.

00:17:35.762 --> 00:17:37.327
Like stromatolites on Earth,

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layers of microbes could build up

00:17:39.281 --> 00:17:41.542
into huge rock mounds over time,

00:17:41.542 --> 00:17:44.112
leaving behind eerie structures.

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And in big enough numbers,

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some alien bacteria could leave

00:17:52.248 --> 00:17:54.134
a distinct biosignature

00:17:55.874 --> 00:17:59.293
by exhaling gases that wouldn't
coexist naturally,

00:17:59.293 --> 00:18:01.380
like oxygen and methane.

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(Shawn Domagal-Goldman)
There's ways to make

00:18:07.919 --> 00:18:09.619 line:1
oxygen without life,
there's ways to make

00:18:09.619 --> 00:18:10.937 line:1
methane without life,

00:18:10.937 --> 00:18:12.939 line:1
but to have them in the atmosphere together

00:18:12.939 --> 00:18:14.558 line:1
is almost impossible unless you've got

00:18:14.558 --> 00:18:16.581 line:1
biology making those gases at the surface.

00:18:17.670 --> 00:18:19.107 line:1
And it would have an imprint

00:18:19.107 --> 00:18:20.877 line:1
on the planet's spectrum of colors.

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(Narrator)
Next-generation space telescopes

00:18:24.694 --> 00:18:26.502
could find a signal like this,

00:18:28.384 --> 00:18:30.751
on a world not far from home.

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(Chris Crowe)
The closest Sun-like star

00:18:33.941 --> 00:18:37.757 line:1
with an Earth-like exoplanet
in the habitable zone

00:18:37.757 --> 00:18:40.419 line:1
is probably only 20 light years away,

00:18:40.419 --> 00:18:42.499 line:1
and can be seen with the naked eye.

00:19:06.209 --> 00:19:08.209
Most brown dwarfs are too hot

00:19:08.209 --> 00:19:10.086
to support life as we know it.

00:19:10.986 --> 00:19:12.671
But some are just cold enough.

00:19:24.419 --> 00:19:26.235
All the prime elements for life

00:19:26.235 --> 00:19:28.754
have been detected
inside their atmospheres.

00:19:31.458 --> 00:19:33.016
And within these clouds,

00:19:33.016 --> 00:19:34.498
some layers would provide

00:19:34.498 --> 00:19:36.340
ideal temperatures and pressures

00:19:36.340 --> 00:19:37.504
for habitability.

00:19:46.073 --> 00:19:48.905
There could be photosynthetic plankton
in these skies,

00:19:49.992 --> 00:19:52.585
kept aloft by churning upwinds.

00:19:57.463 --> 00:19:58.780
And with enough force,

00:19:58.780 --> 00:20:00.578
these upwinds could even support

00:20:00.578 --> 00:20:02.916
larger, more complex life.

00:20:06.011 --> 00:20:06.796
Predators.

00:20:44.072 --> 00:20:46.163
This raises a crucial question:

00:20:47.635 --> 00:20:50.439
what if we've been looking in
all the wrong places?

00:20:52.523 --> 00:20:55.125
What if nature has other ideas?

00:21:20.931 --> 00:21:24.295
Most of the universe
is too cold or too hot

00:21:24.295 --> 00:21:26.420
for liquid water and the biochemistry

00:21:26.420 --> 00:21:28.295
that supports life as we know it.

00:21:31.304 --> 00:21:33.724
But in case our biases are misleading,

00:21:34.520 --> 00:21:36.453
we have to cast a wide net—

00:21:38.748 --> 00:21:42.051
to search for life outside
the habitable zone,

00:21:42.051 --> 00:21:45.003
in places that seem wildly hostile to us.

00:21:49.416 --> 00:21:51.348
Exotic environments will demand

00:21:51.348 --> 00:21:53.406
exotic biochemistries,

00:21:53.406 --> 00:21:56.895
and while no element can match
carbon's versatility,

00:21:56.895 --> 00:21:58.738
one contender is a frontrunner.

00:22:07.508 --> 00:22:08.624 line:1
At first glance,

00:22:08.624 --> 00:22:10.752 line:1
silicon seems similar to carbon.

00:22:12.746 --> 00:22:14.933 line:1
It forms the same four-way bonds

00:22:14.933 --> 00:22:16.934 line:1
and is also abundant in the universe.

00:22:19.216 --> 00:22:21.000 line:1
But a closer look reveals that

00:22:21.000 --> 00:22:23.263 line:1
these two elements are false twins.

00:22:27.148 --> 00:22:29.138
Silicon bonds are weaker,

00:22:29.138 --> 00:22:32.503
and less prone to forming
large, complex molecules.

00:22:36.160 --> 00:22:37.515
Despite this,

00:22:37.515 --> 00:22:40.820
they can withstand a wider range
of temperatures,

00:22:40.820 --> 00:22:43.795
opening up intriguing possibilities.

00:22:47.191 --> 00:22:49.238
(Carl Sagan)
Life based on the silicon atom,

00:22:49.238 --> 00:22:50.588
instead of carbon,

00:22:50.588 --> 00:22:53.290
would be more resistant to the
extreme cold,

00:22:54.568 --> 00:22:56.723
providing a whole new range

00:22:56.723 --> 00:22:58.057
of weird forms.

00:23:01.101 --> 00:23:02.901
(Narrator)
But silicon has a problem:

00:23:04.416 --> 00:23:06.215
in the presence of oxygen,

00:23:06.215 --> 00:23:07.936
it binds into solid rock.

00:23:10.127 --> 00:23:12.104
To avoid turning to stone,

00:23:12.104 --> 00:23:14.142 line:1
silicon beings might be confined

00:23:14.142 --> 00:23:16.318 line:1
to oxygen-free environments,

00:23:16.318 --> 00:23:18.098 line:1
like Saturn's frigid moon,

00:23:18.098 --> 00:23:18.811 line:1
Titan.

00:23:22.907 --> 00:23:25.674 line:1
Its vast lakes of
liquid methane and ethane

00:23:25.674 --> 00:23:27.131
could be an ideal medium

00:23:27.131 --> 00:23:29.027
for silicon-based life,

00:23:29.027 --> 00:23:31.646
or other radical biochemistries.

00:23:37.105 --> 00:23:38.743
Without ample sunlight,

00:23:38.743 --> 00:23:41.023
beings on worlds like Titan

00:23:41.023 --> 00:23:43.117
would likely be chemosynthetic,

00:23:43.117 --> 00:23:46.171
deriving their energy
by breaking down rocks.

00:24:01.426 --> 00:24:02.883
Such life forms could have

00:24:02.883 --> 00:24:04.720
ultra slow metabolisms,

00:24:04.720 --> 00:24:05.807
and life cycles

00:24:05.807 --> 00:24:07.936
measured in millions of years.

00:24:25.821 --> 00:24:27.114 line:1
In high temperatures,

00:24:27.114 --> 00:24:29.631 line:1
typically rigid silicon-oxygen bonds

00:24:29.631 --> 00:24:31.903 line:1
become more flexible and reactive,

00:24:32.674 --> 00:24:34.918
triggering more dynamic chemistry.

00:24:39.930 --> 00:24:43.456
This has led to a truly bizarre proposal:

00:24:43.456 --> 00:24:45.307
silicon-based lifeforms

00:24:45.307 --> 00:24:48.482
that live inside molten silicate rock.

00:25:00.753 --> 00:25:03.315
In theory,
these forms could even exist

00:25:03.315 --> 00:25:06.094
deep beneath the Earth inside
magma chambers

00:25:06.094 --> 00:25:08.458
as part of a shadow biosphere.

00:25:12.142 --> 00:25:13.487
If so,

00:25:13.487 --> 00:25:16.669
then the aliens are right under our noses.

00:25:20.559 --> 00:25:23.460
Other shadow biospheres
have been proposed—

00:25:23.460 --> 00:25:25.462
forms of life living alongside us

00:25:25.462 --> 00:25:27.338
that we don't even know are here—

00:25:27.338 --> 00:25:31.131
including tiny RNA-based life
small enough to go

00:25:31.131 --> 00:25:33.577
undetected by existing instruments.

00:25:46.741 --> 00:25:48.772
Clouds of dust and empty space

00:25:48.772 --> 00:25:50.775
might seem like the last place
you'd expect

00:25:50.775 --> 00:25:52.126
to find anything living.

00:25:54.197 --> 00:25:55.585 line:1
But when cosmic dust

00:25:55.585 --> 00:25:59.148 line:1
makes contact with plasma,
a type of ionized gas,

00:25:59.148 --> 00:26:00.911 line:1
something strange happens.

00:26:05.550 --> 00:26:07.235
In simulated conditions,

00:26:07.235 --> 00:26:08.943
dust particles have been seen

00:26:08.943 --> 00:26:11.123
spontaneously self-organizing into

00:26:11.123 --> 00:26:13.762
helical structures that resemble DNA.

00:26:18.588 --> 00:26:19.992
These plasma crystals

00:26:19.992 --> 00:26:22.379
even begin to exhibit lifelike behavior:

00:26:23.578 --> 00:26:24.559
replicating,

00:26:24.559 --> 00:26:26.833
evolving into more stable forms,

00:26:26.833 --> 00:26:28.668
and passing on information.

00:27:12.110 --> 00:27:14.796 line:1
Plasma is the most common state of matter

00:27:14.796 --> 00:27:15.945 line:1
in the universe.

00:27:17.386 --> 00:27:19.856 line:1
If complex, evolving plasma crystals

00:27:19.856 --> 00:27:20.966 line:1
really exist,

00:27:20.966 --> 00:27:23.122 line:1
and if they can be considered life,

00:27:23.122 --> 00:27:25.419 line:1
they could be its most common form.

00:27:51.260 --> 00:27:52.919
When massive suns explode,

00:27:52.919 --> 00:27:55.523
some collapse into ultra dense cores

00:27:55.523 --> 00:27:57.041
called neutron stars.

00:27:57.826 --> 00:28:00.158
Hulking masses of atomic nuclei,

00:28:00.158 --> 00:28:02.071
crammed together like sardines.

00:28:05.306 --> 00:28:07.965
Conditions on the surface are
mind-boggling—

00:28:08.712 --> 00:28:11.147
gravity is a hundred billion times

00:28:11.147 --> 00:28:12.206
stronger than Earth's.

00:28:15.464 --> 00:28:17.711
But beneath their iron nuclei crust

00:28:17.711 --> 00:28:19.563
lies something strange:

00:28:21.334 --> 00:28:22.796
a hot dense sea

00:28:22.796 --> 00:28:25.504
of neutrons and subatomic particles.

00:28:34.310 --> 00:28:36.396
Stripped of their electron shells,

00:28:36.396 --> 00:28:37.771
these nuclei would obey

00:28:37.771 --> 00:28:40.380
entirely different laws of chemistry,

00:28:40.380 --> 00:28:42.914
based not on the electromagnetic force,

00:28:42.914 --> 00:28:45.047
but the strong nuclear force

00:28:45.047 --> 00:28:46.838
which binds nuclei together.

00:28:49.595 --> 00:28:50.614
In theory,

00:28:50.614 --> 00:28:54.646
these particles could link up to form
larger macronuclei,

00:28:54.646 --> 00:28:57.143
which could then combine into even bigger

00:28:57.143 --> 00:28:58.223
"super nuclei".

00:29:06.596 --> 00:29:07.785
If so,

00:29:07.785 --> 00:29:09.535
then this bewildering environment

00:29:09.535 --> 00:29:12.404
would mimic the basic conditions for life—

00:29:12.404 --> 00:29:14.084
heavy nucleon molecules,

00:29:14.084 --> 00:29:16.827
floating in a complex particle ocean.

00:29:22.509 --> 00:29:25.338
Some scientists have proposed
the unimaginable:

00:29:26.349 --> 00:29:27.783
exotic life forms

00:29:27.783 --> 00:29:30.953
drifting through the strange particle sea,

00:29:30.953 --> 00:29:33.019
living, evolving, and dying

00:29:33.019 --> 00:29:35.979
on incomprehensibly fast time scales.

00:30:19.336 --> 00:30:20.581
Life is not something

00:30:20.581 --> 00:30:22.628
that has to evolve naturally.

00:30:26.186 --> 00:30:27.454
It can be designed.

00:30:41.406 --> 00:30:43.438
And once intelligence is introduced

00:30:43.438 --> 00:30:46.086
into the evolutionary process,

00:30:46.086 --> 00:30:48.262
a Pandora's box is opened.

00:31:05.977 --> 00:31:08.973
Free from typical biological limitations,

00:31:08.973 --> 00:31:11.003
synthetic and machine-based life

00:31:11.003 --> 00:31:13.086
could be the most successful of all.

00:31:16.507 --> 00:31:18.575
It could thrive almost anywhere,

00:31:18.575 --> 00:31:20.685
including the vacuum of space,

00:31:20.685 --> 00:31:22.543
opening up vast frontiers

00:31:22.543 --> 00:31:25.221
unavailable to biological organisms.

00:31:31.737 --> 00:31:34.941
And compared to the glacial pace
of natural selection,

00:31:34.941 --> 00:31:36.834
technological evolution

00:31:36.834 --> 00:31:39.475
allows exponentially faster growth,

00:31:39.475 --> 00:31:41.919
adaptability, and resilience.

00:31:56.067 --> 00:31:59.477
By some estimates,
autonomous self-replicating machines

00:31:59.477 --> 00:32:01.770
could colonize an entire galaxy

00:32:01.770 --> 00:32:03.896
in as little as a million years.

00:32:18.687 --> 00:32:21.484
We can't predict how hyperintelligent life

00:32:21.484 --> 00:32:22.978
would organize itself,

00:32:26.367 --> 00:32:27.407
but in theory,

00:32:27.407 --> 00:32:30.013
there could be convergent evolution
at play.

00:32:32.177 --> 00:32:34.433
The electrical properties of silicon

00:32:34.433 --> 00:32:36.326
might make it a universal basis

00:32:36.326 --> 00:32:38.002
for machine intelligence,

00:32:38.567 --> 00:32:41.704
a redemption for its biological
shortcomings.

00:33:53.263 --> 00:33:55.065
As the universe ages,

00:33:55.065 --> 00:33:57.960
perhaps machine intelligence will come
to dominate,

00:33:58.633 --> 00:34:01.040
and naturally occurring biological life

00:34:01.040 --> 00:34:03.748
will be viewed as a quaint starting point.

00:34:09.453 --> 00:34:10.702
Perhaps we ourselves

00:34:10.702 --> 00:34:12.251
will lead this transition,

00:34:12.973 --> 00:34:14.533
and the great human experiment

00:34:14.533 --> 00:34:16.401
would be merely a first link

00:34:16.401 --> 00:34:19.962
in a sprawling intergalactic chain
of life.

00:35:27.449 --> 00:35:29.749
Loren Eiseley has said

00:35:29.749 --> 00:35:31.669
that one does not meet oneself

00:35:31.669 --> 00:35:34.347
until one catches the reflection

00:35:34.347 --> 00:35:36.261
from an eye other than human.

00:35:38.665 --> 00:35:40.918
One day that eye may be

00:35:40.918 --> 00:35:42.877
that of an intelligent alien.

00:35:45.662 --> 00:35:47.775
And the sooner we eschew

00:35:47.775 --> 00:35:50.685
our narrow view of evolution,

00:35:52.024 --> 00:35:55.828
the sooner we can truly explore

00:35:55.828 --> 00:35:59.310
our ultimate origins and destinations.

00:36:35.094 --> 00:36:40.089
English captions by
vrgtics, ericksoares3, and KillerGhoul