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Ever worry
about picking up a bug?
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What if we have all caught
something...
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Something unidentifiable
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00:00:23,144 --> 00:00:25,649
and from unknown origins?
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00:00:30,051 --> 00:00:32,120
Not from each other.
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From the heavens.
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Drops of rain could be
bringing us visitors
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from another planet ...
Aliens invading our bloodlines
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00:00:43,233 --> 00:00:47,470
or maybe even
infecting our technology.
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00:00:47,569 --> 00:00:51,005
They could be hidden
in packets of digital data,
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in a form
we don't even recognize as life.
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Alien intelligence may be
tracking our every move.
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We haven't found
any extraterrestrials yet,
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00:01:04,186 --> 00:01:08,822
but maybe we're looking
in the wrong places.
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Are aliens inside us?
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Space, time, life itself.
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The secrets of the cosmos
lie through the wormhole.
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Captions by vitac
www.Vitac.Com
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captions paid for by
discovery communications
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the size of the universe
is really hard to comprehend.
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Hundreds of billions of stars
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in our galaxy and billions
of galaxies beyond.
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It seems impossible to imagine
that the only place life
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exists is here on earth.
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Are we the only intelligent
life-form in the cosmos?
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If not,
then where are the others?
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In the past, we've always
looked up to the heavens.
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But to find alien life,
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maybe we only need to look down,
within our world
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and inside our bodies.
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This man has alien intruders
inside of him right now.
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Cedric Feschotte is a geneticist
at the university of Utah.
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He's well aware that he,
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like every living
being on the planet,
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hosts foreign viruses
and bacteria.
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But Cedric is focused
on more insidious intruders.
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See them in genome sequences.
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Many copies,
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but we really don't understand
how they got there.
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Freeman: These alien entities
are called transposons.
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They're pieces of DNA
which sneak in from the outside
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and insert themselves
into our genes.
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So they copy and paste
to new places in the genome.
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This replication is independent
from the replication
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of the whole set.
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And they do this much more often
than the set actually replicate.
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Freeman: They're not just
invading human cells.
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Virtually every living thing
on earth contains transposons.
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Feschotte: In fact, they are
the single largest components
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of the genome of many plants,
many animals as well.
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We like to call
them space invaders.
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Freeman:
Our DNA comes to us in a direct line from our ancestors,
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generation after generation.
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And that genetic inheritance
also includes the transposons
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that snuck
into our ancestors' DNA.
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Every once in a while,
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a new transposon
mysteriously finds its way in,
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like a skateboard that suddenly
appears and becomes part
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of the way Cedric's ancestor
moved through the world.
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These alien intruders
can continue multiplying
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and passing down
to successive generations
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until a single transposon
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exists in the entire population
of a species.
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And transposons are so good
at replicating inside of us
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that half of our DNA
is now alien.
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When the transposon jump
into the chromosome,
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it's like a mutation.
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Something new was introduced
there.
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So most of the transposons
in your genome
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don't really affect you,
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just like these bunny ears today
won't really affect my skating.
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Freeman: Other transposons
can be helpful.
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In fact, one of these intruders
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became the foundation
for our immune system.
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It's like a helmet
suddenly appearing to protect
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Cedric's head.
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This transposon arrived
millions of years ago
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and gave us the ability
to create antibodies,
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a crucial line of defense
against pathogens.
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Feschotte:
And without this transposon,
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we just probably
would not be here today.
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Freeman: The transposons
can also cause problems.
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Sometimes, transposons
can be harmful, too,
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like this blindfold on my head.
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Cant find my skateboard now.
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There's over
100 different genetic disease
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tied to transposition events.
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This can really be so bad
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that it could lead
to extinction of a species,
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just like a virus could spread
and turn into a pandemic.
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Freeman:
Cedric thinks it's possible
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that transposons
break into our cells
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by attaching themselves
to viruses.
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Feschotte: They could piggyback
onto a virus.
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And then this virus
can infect a new cell.
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And then the transposon
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can infiltrate that new
individual or that new species.
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Freeman: As the virus
goes about its business,
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disrupting our DNA,
the transposon sneaks in, too,
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and never leaves.
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But the biggest mystery
of all is where these bits
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of self-replicating DNA
come from in the first place.
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They are so abundant,
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yet we know very little
about them.
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In fact, it's really like
the dark matter of the genome.
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Could the space invaders
taking up so much room
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in our DNA have actually come
from outer space?
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We still haven't found
any other signs
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of life in our solar system.
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That means alien pieces of DNA
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would have to come
from a distant star system.
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But how could anything
biological
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survive that kind of trip?
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University of Michigan
astrophysicist
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Fred Adams
believes he has an answer.
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According to a theory,
known as panspermia,
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life spreads around the universe
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when a comet
or asteroid hits a planet.
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The impact sends debris shooting
all the way up into space
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and eventually onto the surface
of another planet.
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We see meteorites from Mars
on a somewhat regular basis.
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So we do know that there's
transfer from Mars to earth.
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Freeman: However, martian rocks
don't contain life.
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And our other
neighboring planets
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don't appear to have any,
either.
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So Fred started wondering
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if life could've made
a much longer journey to earth
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from outside our own
solar system.
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In order to be transferred,
the elements of life,
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basically bacterial
kind of organisms,
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have to be encased in rock.
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Freeman: The rock provides
protection from extreme cold,
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heat, and damaging radiation.
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The shield needs to be
a little bigger than this ball.
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In order for solar systems
to share rocks,
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two things have to happen.
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The first is that the solar
systems have to eject rocks
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from their immediate vicinity.
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And the second thing
is that another solar system
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has to capture them.
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Freeman: A large enough impact
from an asteroid or a comet
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could easily
produce enough energy
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to shoot debris
out of a solar system.
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But whether it can hit a planet
orbiting another sun
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is much less certain.
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Space is relentlessly empty,
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which makes rock transfer
between solar systems
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very difficult.
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Freeman: There's an average
of four to five light-years
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between solar systems
in our galaxy.
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Even if you could launch
a space rock that far,
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what are the chances
of hitting another planet
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up to 30 trillion Miles away?
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Okay, let's consider
a simple analogy.
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Each of these lacrosse players
will represent a solar system,
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and the ball will represent
a life-bearing rock.
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As the players throw the ball
back and forth to each other,
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it's like a rock
being transferred
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from one solar system
to another.
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Let's see what happens.
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Freeman: Suppose the length of a lacrosse
field represents a light-year.
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Even if a player could throw
a ball four or five fields away,
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consider how unlikely
it would be for that player
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to toss a ball blindly
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and have it land
in the pocket of a teammate.
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And distance
isn't the only factor.
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Solar systems in our galaxy
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are also flying around
each other
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120 times faster
than the speed of sound.
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So now the teammate
has to be running full speed.
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Even when an alien rock's
trajectory is on target,
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it's almost always
moving too fast for gravity
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in the new solar system
to catch it.
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Imagine the difficulty
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in catching a speeding lacrosse
ball from hundreds of yards
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away while running
and with a broken net.
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Not surprisingly,
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when Fred ran the numbers
calculating the distance
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between earth
and other solar systems,
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factoring in the movements
of stars and planets,
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it seemed impossible
that an alien rock
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could ever find earth
from so far away.
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But then Fred
realized something he'd missed,
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something that suddenly made it
a lot more likely that aliens
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could have landed here.
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Four and a half billion
years ago,
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things were a lot different.
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Alien suns
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and their surrounding planets
crowded earth's night sky.
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Neighboring solar systems
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were roughly 10 times closer
than they are today.
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Now the lacrosse players can be
dozens of yards from each other
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instead of hundreds.
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In the early part
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of the evolution
of the solar system,
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the solar system
was living in a dense cluster.
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Freeman: And solar systems back then
were moving around each other
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40 times more slowly than today.
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On the lacrosse field,
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00:11:16,365 --> 00:11:19,033
that makes completing a pass
a lot simpler.
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00:11:19,034 --> 00:11:22,802
Adams: If the players are close
together and moving slowly,
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00:11:22,803 --> 00:11:25,072
it's easy for them
to pass the ball from one person
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00:11:25,073 --> 00:11:26,340
to the other.
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00:11:26,341 --> 00:11:30,043
Freeman: If Fred is right,
billions of years ago,
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00:11:30,044 --> 00:11:31,546
our home planet
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00:11:31,547 --> 00:11:36,216
would've been in position to
snare ancient alien organisms.
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00:11:36,217 --> 00:11:39,019
Could they have seeded life
on earth?
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00:11:39,020 --> 00:11:41,656
This biologist thinks they did
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00:11:41,657 --> 00:11:45,592
and that they're still
raining down on us today.
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00:11:45,593 --> 00:11:50,532
He says he has proof
that organisms from outer space
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00:11:50,533 --> 00:11:55,071
are in our atmosphere right now.
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00:11:57,000 --> 00:11:58,933
The seeds of life on earth
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00:11:58,934 --> 00:12:01,503
may have arrived billions
of years ago
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00:12:01,504 --> 00:12:04,705
from a distant alien world.
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00:12:04,706 --> 00:12:07,808
But if life got here
by hiding on a meteorite
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00:12:07,809 --> 00:12:11,846
fallen from the sky...
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00:12:11,847 --> 00:12:14,784
Could it still be
raining down on us right now?
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00:12:21,157 --> 00:12:24,326
Milton Wainwright
is a microbiologist
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00:12:24,327 --> 00:12:27,829
at the university of sheffield
in england.
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00:12:27,830 --> 00:12:29,864
He believes he's found evidence
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00:12:29,865 --> 00:12:35,470
that extraterrestrial life falls
like rain from the heavens.
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00:12:35,471 --> 00:12:39,175
Wainwright: So the basic idea of
panspermia is that life came from space.
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00:12:39,176 --> 00:12:40,443
There was no life on earth.
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00:12:40,444 --> 00:12:44,680
That life was delivered
by asteroids and comets.
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00:12:44,681 --> 00:12:47,516
Now, Neo-panspermia,
Neo meaning new, uh,
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00:12:47,517 --> 00:12:51,186
suggests that life
is continuing to come from space
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00:12:51,187 --> 00:12:54,223
at this very minute.
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00:12:54,224 --> 00:12:57,627
Freeman: In 2013, Milton and
his team collected samples
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00:12:57,628 --> 00:13:02,330
from the stratosphere
some 16 Miles up.
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00:13:02,331 --> 00:13:07,635
That's three times higher
than commercial jetliners fly.
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00:13:07,636 --> 00:13:10,840
The lower atmosphere
is full of life,
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00:13:10,841 --> 00:13:14,877
but Milton thinks
the stratosphere is, too.
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00:13:14,878 --> 00:13:16,711
His controversial claim
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00:13:16,712 --> 00:13:20,917
is that it contains life forms
from outer space.
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00:13:20,918 --> 00:13:24,652
The suggestion by the critics
is this material is going up
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00:13:24,653 --> 00:13:26,620
and not coming down from space.
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00:13:26,621 --> 00:13:28,356
It's just earth material.
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00:13:28,357 --> 00:13:31,726
Now, there's a number of reasons
why we think that's wrong.
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00:13:31,727 --> 00:13:33,461
Freeman:
Milton counters that his samples
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00:13:33,462 --> 00:13:38,700
came from far too high to have
been blown upward by the wind.
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00:13:38,701 --> 00:13:40,801
Wainwright: Physics tells us
that the particles
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00:13:40,802 --> 00:13:44,239
we have are too big
to reach the stratosphere.
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00:13:44,240 --> 00:13:45,641
Now, that's just physics.
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00:13:45,642 --> 00:13:47,010
And you can't argue
with physics.
245
00:13:47,011 --> 00:13:49,644
You can't argue
with Newton's laws.
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00:13:49,645 --> 00:13:52,614
Freeman: But Milton is aware
that the only way he's going
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00:13:52,615 --> 00:13:57,518
to convince the skeptics
is to find more aliens.
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00:13:57,519 --> 00:14:00,788
If microorganisms or any life
is coming in from space,
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00:14:00,789 --> 00:14:02,356
we have to go out and catch it.
250
00:14:02,357 --> 00:14:05,194
[ Air hissing ]
251
00:14:05,195 --> 00:14:09,831
Freeman: And that's exactly
what Milton is doing.
252
00:14:09,832 --> 00:14:12,768
He and his team
are conducting a new series
253
00:14:12,769 --> 00:14:17,339
of high-altitude missions.
254
00:14:17,340 --> 00:14:21,377
Yep. Bon voyage,
stratosphere sampler.
255
00:14:21,378 --> 00:14:23,879
Whoa!
256
00:14:26,149 --> 00:14:29,017
The team waits for about
90 minutes while the balloon
257
00:14:29,018 --> 00:14:32,620
climbs 80,000 feet.
258
00:14:32,621 --> 00:14:38,926
Once there, a drawer mounted
inside the payload opens.
259
00:14:38,927 --> 00:14:41,263
So this is what happens
in the stratosphere.
260
00:14:41,264 --> 00:14:42,663
The drawer opens.
261
00:14:42,664 --> 00:14:46,335
The samples are collected
on electron microscope stubs.
262
00:14:46,336 --> 00:14:49,937
We can take those directly from
here, under sterile conditions,
263
00:14:49,938 --> 00:14:51,806
into the electron microscope.
264
00:14:51,807 --> 00:14:53,542
Freeman: Sixteen miles up,
265
00:14:53,543 --> 00:14:56,545
the air pressure is so low
that the balloon
266
00:14:56,546 --> 00:15:00,782
continues to expand
until it ruptures
267
00:15:00,783 --> 00:15:04,387
and tumbles back to earth
with this precious cargo.
268
00:15:04,388 --> 00:15:05,588
Wainwright:
This is a fishing trip.
269
00:15:05,589 --> 00:15:06,754
We're sending these balloons up.
270
00:15:06,755 --> 00:15:07,989
We don't know
what we're catching.
271
00:15:07,990 --> 00:15:09,658
So, on some trips,
we'll catch nothing.
272
00:15:09,659 --> 00:15:11,125
On some trips,
we'll catch something.
273
00:15:11,126 --> 00:15:14,028
And maybe we'll go
for five launches with nothing,
274
00:15:14,029 --> 00:15:15,531
and then the sixth launch,
275
00:15:15,532 --> 00:15:18,633
we get an amazing array
of organisms.
276
00:15:18,634 --> 00:15:23,439
Freeman:
He's hoping his latest launch will yield something like this.
277
00:15:23,440 --> 00:15:25,241
These are photos
of samples Milton
278
00:15:25,242 --> 00:15:29,778
and his team collected
on their first mission in 2013.
279
00:15:29,779 --> 00:15:32,880
And Milton believes
they contain evidence
280
00:15:32,881 --> 00:15:36,718
of extraterrestrial life.
281
00:15:36,719 --> 00:15:39,222
Wainwright: This is the first
amazing organism we found.
282
00:15:39,223 --> 00:15:41,623
If we go to a textbook,
283
00:15:41,624 --> 00:15:45,194
for algae, bacteria, we
don't see something like this.
284
00:15:45,195 --> 00:15:46,961
Freeman:
Milton's supposed aliens
285
00:15:46,962 --> 00:15:49,697
are only
about 30 microns across,
286
00:15:49,698 --> 00:15:53,502
roughly twice the thickness
of a human hair.
287
00:15:53,503 --> 00:15:55,771
Wainwright: At first, I was
very upset about this structure
288
00:15:55,772 --> 00:15:57,806
because I thought
it was a ... a pollen grain.
289
00:15:57,807 --> 00:15:59,508
But when we
do the chemical analysis,
290
00:15:59,509 --> 00:16:02,411
we found it was primarily
titanium.
291
00:16:02,412 --> 00:16:04,814
And you can see that there's
material coming out of the ball.
292
00:16:04,815 --> 00:16:08,048
And when we analyze this,
it turns out to be biological.
293
00:16:08,049 --> 00:16:09,784
This is carbon and oxygen.
294
00:16:09,785 --> 00:16:11,319
It's biological.
295
00:16:11,320 --> 00:16:15,023
Freeman:
No life form yet discovered has a titanium shell.
296
00:16:15,024 --> 00:16:16,858
This might be the first.
297
00:16:16,859 --> 00:16:20,329
And, more crucial
to Milton's case,
298
00:16:20,330 --> 00:16:23,400
no earthly organism
would be moving fast enough
299
00:16:23,401 --> 00:16:26,402
to leave an impact crater
on the collector.
300
00:16:26,403 --> 00:16:29,071
Wainwright: We see that there's
an impact crater here.
301
00:16:29,072 --> 00:16:32,574
So this ball was coming in from
space, impacted the sampler,
302
00:16:32,575 --> 00:16:34,877
and caused a crater.
303
00:16:34,878 --> 00:16:37,213
The impact event
means it's coming from outside.
304
00:16:37,214 --> 00:16:40,148
It is not lazily drifting up
from the earth.
305
00:16:40,149 --> 00:16:42,152
It's coming at a great speed.
306
00:16:44,187 --> 00:16:47,855
Milton thinks comets
might be the source.
307
00:16:47,856 --> 00:16:49,224
Wainwright:
The temperature is right.
308
00:16:49,225 --> 00:16:50,526
The amount of water is right.
309
00:16:50,527 --> 00:16:53,796
The amount of carbon
and organic material is right.
310
00:16:53,797 --> 00:16:55,898
Freeman: Debris from their
frozen tails could be
311
00:16:55,899 --> 00:16:59,336
littering our atmosphere
with alien organisms.
312
00:17:01,937 --> 00:17:05,073
Hoping to replicate the success
of his first launch,
313
00:17:05,074 --> 00:17:08,610
Milton has another half dozen
planned.
314
00:17:08,611 --> 00:17:11,447
The big fear I have is
that we got these amazing images
315
00:17:11,448 --> 00:17:13,015
and we never repeat it.
316
00:17:13,016 --> 00:17:15,752
Now, in science, of course,
a one-off is nothing.
317
00:17:15,753 --> 00:17:18,720
We need to get a repetition
of something.
318
00:17:18,721 --> 00:17:21,923
Freeman: Even if Milton
does find more alien microbes,
319
00:17:21,924 --> 00:17:26,795
he cautions that they might look
more familiar than we expect.
320
00:17:26,796 --> 00:17:29,163
If they've been
arriving for eons,
321
00:17:29,164 --> 00:17:33,268
we may already share a lot
in common with their biology.
322
00:17:33,269 --> 00:17:36,304
Everyone expects something
from space to be special.
323
00:17:36,305 --> 00:17:39,007
There's not necessarily
anything special about them.
324
00:17:39,008 --> 00:17:40,610
If they're coming in,
they've been coming in
325
00:17:40,611 --> 00:17:41,742
from millions of years.
326
00:17:41,743 --> 00:17:42,876
They're here.
327
00:17:42,877 --> 00:17:44,947
We are part of space.
328
00:17:44,948 --> 00:17:47,350
These organisms are part
of our biology.
329
00:17:50,385 --> 00:17:53,154
Freeman: If alien microbes
are capable of reaching earth
330
00:17:53,155 --> 00:17:55,457
from across the galaxy,
331
00:17:55,458 --> 00:17:58,127
then could intelligent
extraterrestrials
332
00:17:58,128 --> 00:18:00,729
also come here?
333
00:18:00,730 --> 00:18:03,565
We've seen no sign of them.
334
00:18:03,566 --> 00:18:09,038
Or are we searching
for the wrong kind of signal?
335
00:18:12,900 --> 00:18:15,536
If intelligent aliens
were to send us a message
336
00:18:15,537 --> 00:18:19,772
from a distant planet,
would we hear it?
337
00:18:19,773 --> 00:18:21,642
200 years ago,
338
00:18:21,643 --> 00:18:23,876
no one would have picked up
a morse code
339
00:18:23,877 --> 00:18:26,747
on a telegraph wire,
340
00:18:26,748 --> 00:18:31,085
much less a voice
on the cellular network.
341
00:18:31,086 --> 00:18:33,555
Perhaps we just don't have
the technology yet
342
00:18:33,556 --> 00:18:35,757
to answer a call from an alien.
343
00:18:38,860 --> 00:18:41,796
University of Hawaii physicist
John learned
344
00:18:41,797 --> 00:18:46,666
thinks alien messages
may be within our reach.
345
00:18:46,667 --> 00:18:50,569
We cannot guess what some
extraterrestrial intelligence
346
00:18:50,570 --> 00:18:52,772
may be having in mind
347
00:18:52,773 --> 00:18:55,943
for why they would communicate
or how they would communicate.
348
00:18:55,944 --> 00:18:59,445
So the best we can do is just
look to see what is there.
349
00:18:59,446 --> 00:19:01,714
Freeman: If extraterrestrials
are out there
350
00:19:01,715 --> 00:19:04,952
and can send messages
throughout the galaxy,
351
00:19:04,953 --> 00:19:08,722
John says they'll be using
communications technology
352
00:19:08,723 --> 00:19:12,759
very different from our own.
353
00:19:12,760 --> 00:19:16,297
When we send messages
over long distances on earth,
354
00:19:16,298 --> 00:19:21,734
we rely on pulses of light
or radio waves.
355
00:19:21,735 --> 00:19:24,637
However, using light
for interstellar communication
356
00:19:24,638 --> 00:19:26,742
would be spotty at best.
357
00:19:28,810 --> 00:19:32,011
Learned:
There's a lot of dust and gas out there in the universe,
358
00:19:32,012 --> 00:19:34,214
and that scatters light.
359
00:19:34,215 --> 00:19:38,452
So it wouldn't do to try
to have light signaling
360
00:19:38,453 --> 00:19:41,922
from even our own
galactic center.
361
00:19:41,923 --> 00:19:44,325
Freeman: And messages sent
with radio waves
362
00:19:44,326 --> 00:19:47,994
would have a lot of interference
to fight through.
363
00:19:47,995 --> 00:19:51,065
There's hiss coming
from all over the universe,
364
00:19:51,066 --> 00:19:53,533
from all the stars and galaxies.
365
00:19:53,534 --> 00:19:58,105
So there's background noise
that you have to get around.
366
00:19:58,106 --> 00:20:01,107
By tuning around
with this radio,
367
00:20:01,108 --> 00:20:04,278
there's all kind of noise
that comes and goes.
368
00:20:04,279 --> 00:20:08,615
You have to find a frequency
where the extraterrestrials
369
00:20:08,616 --> 00:20:11,117
would be choosing
to communicate.
370
00:20:11,118 --> 00:20:14,355
The problem in tuning in is
there's no schedule
371
00:20:14,356 --> 00:20:16,523
and no list of ... of stations.
372
00:20:16,524 --> 00:20:19,693
So we don't know quite
where to look.
373
00:20:19,694 --> 00:20:21,461
Freeman: John thinks
there's a better technology
374
00:20:21,462 --> 00:20:24,799
to send messages
across the galaxy.
375
00:20:24,800 --> 00:20:29,204
Aliens might be using a tiny
particle called a neutrino
376
00:20:31,607 --> 00:20:34,574
they're subatomic particles
produced by nuclear reactions,
377
00:20:34,575 --> 00:20:37,376
like those in our sun,
378
00:20:37,377 --> 00:20:40,079
and violent events,
like exploding stars
379
00:20:40,080 --> 00:20:43,517
and gamma ray bursts.
380
00:20:43,518 --> 00:20:46,086
The most intriguing property
of neutrinos
381
00:20:46,087 --> 00:20:48,689
is that they are so small
they can pass through matter
382
00:20:48,690 --> 00:20:50,624
as if it wasn't there.
383
00:20:50,625 --> 00:20:53,126
The kind of dense matter
that stops all light
384
00:20:53,127 --> 00:20:57,431
and most radio waves
can't stop neutrinos.
385
00:20:57,432 --> 00:21:00,166
They pass right through things.
386
00:21:00,167 --> 00:21:01,801
Coming through the walls,
387
00:21:01,802 --> 00:21:04,137
coming up out of the ground
here.
388
00:21:04,138 --> 00:21:07,974
We're in a breeze
of about a million neutrinos
389
00:21:07,975 --> 00:21:10,545
through your thumbnail
per second.
390
00:21:10,546 --> 00:21:12,779
Freeman: In fact,
if there was such a thing
391
00:21:12,780 --> 00:21:15,016
a sunblock for neutrinos,
392
00:21:15,017 --> 00:21:16,584
a neutrino protection factor
393
00:21:16,585 --> 00:21:20,222
of 1 trillion
or more wouldn't suffice.
394
00:21:21,023 --> 00:21:24,525
Even though just a thin layer
of this on my hand
395
00:21:24,526 --> 00:21:29,363
is good enough for photons, uh,
it would have to be vastly,
396
00:21:29,364 --> 00:21:32,634
vastly thicker for stopping
neutrinos.
397
00:21:32,635 --> 00:21:34,903
And, in fact, this umbrella,
398
00:21:34,904 --> 00:21:37,873
which stops the photons
from the sun just fine,
399
00:21:37,874 --> 00:21:39,241
wouldn't do the job.
400
00:21:39,242 --> 00:21:41,777
It would have to be a lead
umbrella a light-year thick
401
00:21:41,778 --> 00:21:45,280
to do the job.
402
00:21:45,281 --> 00:21:47,549
Freeman: John thinks
an alien civilization
403
00:21:47,550 --> 00:21:50,551
might decide to create a beam
of neutrinos
404
00:21:50,552 --> 00:21:51,953
and pulse them,
405
00:21:51,954 --> 00:21:56,459
manufacturing a message
in a kind of cosmic morse code.
406
00:21:59,227 --> 00:22:01,795
But because neutrinos
are so ghostly,
407
00:22:01,796 --> 00:22:05,166
they're extremely tough
to detect or measure.
408
00:22:05,167 --> 00:22:07,235
The largest detector on earth,
409
00:22:07,236 --> 00:22:11,205
called icecube, lies buried
under nearly three kilometers
410
00:22:11,206 --> 00:22:13,907
of ice at the South pole.
411
00:22:13,908 --> 00:22:15,877
86 strands of sensors
412
00:22:15,878 --> 00:22:19,514
wait for one of the neutrinos
streaming through earth
413
00:22:19,515 --> 00:22:20,581
to bump into one
414
00:22:20,582 --> 00:22:23,784
of the electrons
in the surrounding ice.
415
00:22:23,785 --> 00:22:27,856
Icecube picks up only a handful
of neutrino collisions
416
00:22:27,857 --> 00:22:30,524
each year.
417
00:22:30,525 --> 00:22:33,861
Neutrinos vary in energy.
418
00:22:33,862 --> 00:22:38,132
The highest-energy neutrinos
are the most rare.
419
00:22:38,133 --> 00:22:41,470
There's a great controversy
going on right now about,
420
00:22:41,471 --> 00:22:43,172
what are the source of these?
421
00:22:43,173 --> 00:22:45,439
What ... what are the mechanisms
422
00:22:45,440 --> 00:22:48,342
that produce
these high energies?
423
00:22:48,343 --> 00:22:50,244
Freeman:
Because they're so rare,
424
00:22:50,245 --> 00:22:53,282
John believes they could be
great communication tools
425
00:22:53,283 --> 00:22:54,817
for aliens.
426
00:22:54,818 --> 00:22:56,853
If one
of these high-energy neutrinos
427
00:22:56,854 --> 00:23:01,022
makes contact
with an electron inside icecube,
428
00:23:01,023 --> 00:23:03,558
we'll know it.
429
00:23:03,559 --> 00:23:06,793
It'll make
this little explosion,
430
00:23:06,794 --> 00:23:11,832
which is so characteristic that
we could identify it uniquely.
431
00:23:11,833 --> 00:23:13,467
If you saw one,
432
00:23:13,468 --> 00:23:16,237
it would certainly get
your attention.
433
00:23:16,238 --> 00:23:18,973
Freeman: Physicists call
this characteristic burst
434
00:23:18,974 --> 00:23:21,341
the glashow resonance.
435
00:23:21,342 --> 00:23:25,312
The way a high-energy neutrino
interacts with an electron
436
00:23:25,313 --> 00:23:30,319
is similar to what happens
when music meets a wine glass.
437
00:23:30,719 --> 00:23:32,753
[ Wine glass resonates ]
438
00:23:32,754 --> 00:23:33,538
Hey, guys.
439
00:23:33,539 --> 00:23:34,321
Hey.
440
00:23:34,322 --> 00:23:39,026
All matter
has a natural frequency.
441
00:23:39,027 --> 00:23:41,462
When energy
from an outside source
442
00:23:41,463 --> 00:23:44,098
matches that natural frequency,
443
00:23:44,099 --> 00:23:47,836
the object will vibrate
much more than usual.
444
00:23:47,837 --> 00:23:50,638
That's known as resonance.
445
00:23:50,639 --> 00:23:52,974
So what we've got here is a ...
446
00:23:52,975 --> 00:23:56,744
A glass, hopefully,
a nice, resonant glass.
447
00:23:56,745 --> 00:23:59,113
And we've got a speaker,
448
00:23:59,114 --> 00:24:01,683
which is attached
to an amplifier.
449
00:24:01,684 --> 00:24:04,586
And we're driving
acoustic energy, sound,
450
00:24:04,587 --> 00:24:06,955
very high-intensity sound
toward this.
451
00:24:06,956 --> 00:24:09,323
And we'll try to hit
the resonance in the glass
452
00:24:09,324 --> 00:24:11,725
and break the glass.
453
00:24:11,726 --> 00:24:13,128
Freeman:
You can think of each note
454
00:24:13,129 --> 00:24:17,465
as a different energy level
neutrino and the wine glass
455
00:24:17,466 --> 00:24:19,168
as the electron.
456
00:24:23,004 --> 00:24:26,441
First, John tries various notes
on an organ.
457
00:24:26,841 --> 00:24:29,411
[ Organ plays ]
458
00:24:37,151 --> 00:24:38,919
Now the singer.
459
00:24:38,920 --> 00:24:41,890
[ Vocalizing ]
460
00:24:49,799 --> 00:24:52,367
Finally, the guitar player.
461
00:24:52,368 --> 00:24:55,471
[ Solo plays ]
462
00:25:11,754 --> 00:25:14,723
Learned:
It's a matter of, uh,
463
00:25:14,724 --> 00:25:16,224
getting the right frequency,
464
00:25:16,225 --> 00:25:19,194
getting enough energy
right on the right frequency.
465
00:25:19,195 --> 00:25:20,728
Man, that's gone.
466
00:25:20,729 --> 00:25:23,932
Freeman: The glashow resonance
is the explosion that results
467
00:25:23,933 --> 00:25:29,670
when just the right type
of high-energy neutrino arrives.
468
00:25:29,671 --> 00:25:30,973
John thinks a string
469
00:25:30,974 --> 00:25:34,742
of these rare explosions
wouldn't be a coincidence
470
00:25:34,743 --> 00:25:39,914
but rather a sign of an extra
terrestrial intelligence.
471
00:25:39,915 --> 00:25:43,417
Learned: And if we see those neutrinos
coming from the same direction,
472
00:25:43,418 --> 00:25:44,618
then we certainly
473
00:25:44,619 --> 00:25:47,755
know that that is not
a natural phenomenal.
474
00:25:47,756 --> 00:25:50,224
Would be
the greatest discovery ever.
475
00:25:50,225 --> 00:25:51,693
I can't think of anything
476
00:25:51,694 --> 00:25:54,128
that would be
a more amazing discovery
477
00:25:54,129 --> 00:25:58,733
than to find the first signs
of extraterrestrial life.
478
00:25:58,734 --> 00:26:02,236
It would change our world.
479
00:26:02,237 --> 00:26:07,339
Freeman: As exciting as it would be
to find an alien message,
480
00:26:07,340 --> 00:26:11,579
the simple act of reading it
could threaten our existence.
481
00:26:11,580 --> 00:26:16,119
Alien communication could carry
a lot more than a greeting.
482
00:26:21,491 --> 00:26:25,095
The moment of first contact
with an alien civilization
483
00:26:25,096 --> 00:26:30,332
will be the most important event
in human history.
484
00:26:30,333 --> 00:26:33,336
But if we already missed it?
485
00:26:33,337 --> 00:26:39,241
What if an alien message has
arrived and we didn't notice?
486
00:26:39,242 --> 00:26:41,577
Maybe it's here right now,
487
00:26:41,578 --> 00:26:45,014
hiding inside our technology.
488
00:26:48,284 --> 00:26:49,752
Andrew siemion
489
00:26:49,753 --> 00:26:53,022
specializes in the search for
extraterrestrial intelligence
490
00:26:53,023 --> 00:26:57,359
at u.C. Berkeley's
SETI research center.
491
00:26:57,360 --> 00:26:58,660
He and his colleagues
492
00:26:58,661 --> 00:27:02,165
are looking for unusual signals
in outer space,
493
00:27:02,166 --> 00:27:08,436
hoping to find one that might
come from an alien civilization.
494
00:27:08,437 --> 00:27:11,272
I think that our first encounter
with very advanced life
495
00:27:11,273 --> 00:27:14,542
probably will not come
in a spaceship landing
496
00:27:14,543 --> 00:27:18,147
in golden gate park.
497
00:27:18,148 --> 00:27:20,550
It's quite likely
that it will come via a signal
498
00:27:20,551 --> 00:27:23,618
that we just
happen to eavesdrop on.
499
00:27:23,619 --> 00:27:26,821
Freeman: But it may be that
aliens are already listening
500
00:27:26,822 --> 00:27:28,823
to our radio signals.
501
00:27:28,824 --> 00:27:32,093
If there were very advanced life
nearby to earth,
502
00:27:32,094 --> 00:27:34,097
they've monitored
our radio signals
503
00:27:34,098 --> 00:27:35,464
that have left this planet.
504
00:27:35,465 --> 00:27:39,501
And so they almost certainly
know quite a lot about us.
505
00:27:39,502 --> 00:27:43,272
Since the 1960s,
communications satellites
506
00:27:43,273 --> 00:27:47,542
have been relaying information
from one computer to another.
507
00:27:47,543 --> 00:27:53,582
And that information
has been leaking out into space.
508
00:27:53,583 --> 00:27:56,417
If aliens understand
how our computer networks
509
00:27:56,418 --> 00:28:00,622
operate and know that we're
actively listening for them,
510
00:28:00,623 --> 00:28:04,792
Andrew believes they could take
advantage of the situation.
511
00:28:04,793 --> 00:28:07,195
They could deliver
a digital virus
512
00:28:07,196 --> 00:28:10,098
and know
that we'd scoop it right up.
513
00:28:10,099 --> 00:28:13,735
We gather millions
of radio signals from space
514
00:28:13,736 --> 00:28:17,740
each year in our search
for intelligent communication.
515
00:28:17,741 --> 00:28:20,277
Those signals go
straight to our computers
516
00:28:20,278 --> 00:28:23,678
so researchers can analyze them.
517
00:28:23,679 --> 00:28:25,947
Hunting for evidence
of advanced technology,
518
00:28:25,948 --> 00:28:27,183
these radio signals,
519
00:28:27,184 --> 00:28:30,653
is kind of like hunting
for easter eggs.
520
00:28:30,654 --> 00:28:32,689
We're looking
for that one small nugget
521
00:28:32,690 --> 00:28:35,291
that stands out
from the landscape.
522
00:28:35,292 --> 00:28:37,592
The signals that we look for
are very, very weak,
523
00:28:37,593 --> 00:28:41,397
so we have to sift
through all of the noise,
524
00:28:41,398 --> 00:28:44,198
noise produced from other
astrophysical sources,
525
00:28:44,199 --> 00:28:46,667
quasars and pulsars.
526
00:28:46,668 --> 00:28:50,304
Freeman: Once SETI researchers
gather potential alien signals,
527
00:28:50,305 --> 00:28:52,407
they take a closer look.
528
00:28:52,408 --> 00:28:55,243
But analyzing the signal
on one of our computers
529
00:28:55,244 --> 00:28:58,414
wouldn't be enough to unleash
an alien virus.
530
00:28:58,415 --> 00:29:00,916
Researchers would have
to run the code.
531
00:29:00,917 --> 00:29:02,051
We have to take that data,
532
00:29:02,052 --> 00:29:04,019
and we have to run it
on a computer.
533
00:29:04,020 --> 00:29:09,257
And that's sort of akin
to opening one of these eggs.
534
00:29:09,258 --> 00:29:13,095
Freeman: Advanced alien hackers
would probably notice,
535
00:29:13,096 --> 00:29:17,200
and they'd likely know there's
another way into our networks,
536
00:29:17,201 --> 00:29:20,703
a way that wouldn't be dependent
on a decision by one of us
537
00:29:20,704 --> 00:29:22,804
to run their code.
538
00:29:22,805 --> 00:29:25,607
Hundreds of radio antennas
on earth are specifically
539
00:29:25,608 --> 00:29:29,378
designed to exchange
computer code with each other
540
00:29:29,379 --> 00:29:33,249
and immediately run
those programs.
541
00:29:33,250 --> 00:29:35,617
Siemion: A signal
that was sent by another species
542
00:29:35,618 --> 00:29:37,485
to one of those antennas
543
00:29:37,486 --> 00:29:40,689
could be received
and executed in the same way
544
00:29:40,690 --> 00:29:43,157
that it executes code
that it receives from ...
545
00:29:43,158 --> 00:29:46,128
From human transmissions.
546
00:29:46,129 --> 00:29:48,330
Freeman:
In fact, an alien code
547
00:29:48,331 --> 00:29:54,669
could already be here, operating
undetected in our networks.
548
00:29:54,670 --> 00:29:58,040
The whole idea of a virus
or a trojan horse is to ...
549
00:29:58,041 --> 00:30:00,339
Is to run some code
550
00:30:00,340 --> 00:30:01,542
on a computer
or on a computer network
551
00:30:01,543 --> 00:30:03,411
that no one
knows anything about.
552
00:30:03,412 --> 00:30:08,916
It ... it runs itself, uh,
surreptitiously under the radar.
553
00:30:08,917 --> 00:30:11,853
Freeman: Human hackers have
already shown it's possible
554
00:30:11,854 --> 00:30:15,424
to hide computer viruses
for long periods.
555
00:30:15,425 --> 00:30:17,192
The stuxnet virus,
556
00:30:17,193 --> 00:30:20,195
developed in secret
by the U.S. and Israel,
557
00:30:20,196 --> 00:30:22,897
lurked in the network
of an iranian nuclear facility
558
00:30:22,898 --> 00:30:28,870
for over a year, slowly damaging
hundreds of iranian centrifuges.
559
00:30:28,871 --> 00:30:32,474
The virus sent signals
to the plant's control room,
560
00:30:32,475 --> 00:30:35,977
indicating
everything was normal,
561
00:30:35,978 --> 00:30:41,050
until the centrifuges
finally broke in 2010.
562
00:30:41,051 --> 00:30:45,587
A program from an advanced
civilization could go unnoticed
563
00:30:45,588 --> 00:30:49,824
for much longer and be
far more destructive.
564
00:30:49,825 --> 00:30:52,828
We might be able to recognize it
because it would be a ...
565
00:30:52,829 --> 00:30:54,195
A piece of computer code
566
00:30:54,196 --> 00:30:56,732
that we had never seen
before that was devised by a ...
567
00:30:56,733 --> 00:30:59,834
A completely different species.
568
00:30:59,835 --> 00:31:03,872
Freeman: Could aliens programs
already be inside our technology,
569
00:31:03,873 --> 00:31:08,310
preparing an attack
on our networks?
570
00:31:08,311 --> 00:31:13,749
Or is there perhaps an even more
unnerving possibility?
571
00:31:13,750 --> 00:31:17,484
The aliens themselves may be
in our networks
572
00:31:17,485 --> 00:31:20,121
as digital life-forms.
573
00:31:20,122 --> 00:31:25,094
If so, this man believes
he knows how to find them.
574
00:31:28,799 --> 00:31:33,602
Could alien visitors
have already arrived on earth?
575
00:31:33,603 --> 00:31:34,704
Perhaps they have,
576
00:31:34,705 --> 00:31:38,006
and we just don't recognize
them.
577
00:31:38,007 --> 00:31:41,143
Maybe they aren't made
of flesh and blood or metal
578
00:31:41,144 --> 00:31:45,080
or anything we can touch.
579
00:31:45,081 --> 00:31:50,088
What if aliens
are digital life forms?
580
00:31:56,159 --> 00:31:59,329
Chris adami
of Michigan state university
581
00:31:59,330 --> 00:32:03,766
is an evolutionary biologist
and a computer scientist.
582
00:32:03,767 --> 00:32:07,070
He studies the border between
life as we know it
583
00:32:07,071 --> 00:32:09,505
and life as it might be.
584
00:32:09,506 --> 00:32:11,974
What we really want to do
is have a definition
585
00:32:11,975 --> 00:32:15,278
that does not depend
on the very specifics
586
00:32:15,279 --> 00:32:18,715
of the form of life
that we encounter here on earth.
587
00:32:18,716 --> 00:32:20,582
What is life?
588
00:32:20,583 --> 00:32:24,721
The dictionary will say
it involves metabolism, growth,
589
00:32:24,722 --> 00:32:28,425
reaction to stimuli,
and reproduction.
590
00:32:28,426 --> 00:32:32,195
So plants and animals
are obviously alive.
591
00:32:32,196 --> 00:32:33,996
But what about a robot?
592
00:32:33,997 --> 00:32:37,500
We could imagine a robot
like that to be alive if,
593
00:32:37,501 --> 00:32:41,804
in fact, it could not only
build another robot just like it
594
00:32:41,805 --> 00:32:44,140
but also, in fact,
595
00:32:44,141 --> 00:32:47,743
makes copies
of the programming and inserts
596
00:32:47,744 --> 00:32:51,513
that into the baby robot
that it makes.
597
00:32:51,514 --> 00:32:52,982
If it is doing that,
598
00:32:52,983 --> 00:32:56,786
it will be able to create
a population of robots.
599
00:32:56,787 --> 00:32:58,788
But this thing
is actually not alive.
600
00:32:58,789 --> 00:33:02,891
It was programmed by the people
who built this plant.
601
00:33:02,892 --> 00:33:08,197
It does not actually have
the capacity to self-perpetuate.
602
00:33:08,198 --> 00:33:10,367
Freeman: Because a robot's
operating instructions
603
00:33:10,368 --> 00:33:12,769
come from an outside entity,
604
00:33:12,770 --> 00:33:16,374
it can't adapt or evolve
on its own.
605
00:33:18,676 --> 00:33:20,443
But that doesn't mean
that something artificial
606
00:33:20,444 --> 00:33:22,544
can't be alive.
607
00:33:22,545 --> 00:33:25,013
Chris believes
alien digital life forms
608
00:33:25,014 --> 00:33:28,650
could do everything we do ...
Consume resources,
609
00:33:28,651 --> 00:33:32,254
reproduce,
evolve, all inside a computer.
610
00:33:32,255 --> 00:33:34,389
He knows because he
and his colleagues
611
00:33:34,390 --> 00:33:39,262
created organisms
just like that.
612
00:33:39,263 --> 00:33:40,696
Their digital organisms
613
00:33:40,697 --> 00:33:43,667
live in virtual environment
called avida.
614
00:33:46,536 --> 00:33:48,804
Each dot is an avidian.
615
00:33:48,805 --> 00:33:52,841
Different colors
represent different species.
616
00:33:52,842 --> 00:33:55,244
Adami: They're more like
computer viruses
617
00:33:55,245 --> 00:33:58,013
that can replicate and make
copies of themselves
618
00:33:58,014 --> 00:34:00,516
except these are special
in the sense that,
619
00:34:00,517 --> 00:34:01,818
when they make copies
of themselves,
620
00:34:01,819 --> 00:34:03,885
they might make flawed copies,
621
00:34:03,886 --> 00:34:05,722
in a sense of mutations.
622
00:34:05,723 --> 00:34:09,392
So these copies can actually
evolve in a darwinian manner,
623
00:34:09,393 --> 00:34:11,227
just like it would be doing
in a petri dish.
624
00:34:11,228 --> 00:34:14,997
But in this case,
they are digital organisms.
625
00:34:14,998 --> 00:34:16,532
Freeman:
The survival of any species
626
00:34:16,533 --> 00:34:20,303
depends on having just
the right rate of mutations.
627
00:34:20,304 --> 00:34:23,173
Zero mutations would mean
avidians could only copy
628
00:34:23,174 --> 00:34:26,443
themselves and never evolve.
629
00:34:26,444 --> 00:34:29,211
With too many mutations,
the new version
630
00:34:29,212 --> 00:34:34,417
would no longer be a program,
just random bits of data.
631
00:34:34,418 --> 00:34:36,486
Chris programmed
his virtual organisms
632
00:34:36,487 --> 00:34:38,555
to mutate every generation.
633
00:34:38,556 --> 00:34:42,059
In other words, avidians evolve.
634
00:34:44,094 --> 00:34:46,262
I'm standing in the middle
of a grid that is going to help
635
00:34:46,263 --> 00:34:48,164
us understand how avida works.
636
00:34:48,165 --> 00:34:50,600
And I'm gonna be playing
the role of digital organisms.
637
00:34:50,601 --> 00:34:52,835
And I'm gonna do it like this.
638
00:34:52,836 --> 00:34:54,138
The different color shirts
639
00:34:54,139 --> 00:34:58,074
that I wear represent
different digital organisms.
640
00:34:58,075 --> 00:34:59,944
Freeman: The grid represents
a limited amount
641
00:34:59,945 --> 00:35:05,313
of computer processing power
over which the avidians compete.
642
00:35:05,314 --> 00:35:09,853
Avida is designed
to reward complex calculations,
643
00:35:09,854 --> 00:35:12,855
which we can represent
with movements.
644
00:35:12,856 --> 00:35:15,359
Make a simple
fairly useless movement,
645
00:35:15,360 --> 00:35:17,192
like raising one arm,
646
00:35:17,193 --> 00:35:19,862
and the program
doesn't replicate.
647
00:35:19,863 --> 00:35:22,031
Make a complex, useful movement,
648
00:35:22,032 --> 00:35:24,500
like going
from sitting to standing,
649
00:35:24,501 --> 00:35:27,670
and the program can copy itself.
650
00:35:27,671 --> 00:35:30,505
The more copies
of the same program there are,
651
00:35:30,506 --> 00:35:33,410
the more computing power
they can grab.
652
00:35:36,113 --> 00:35:38,982
Just like real life,
avidians pick up new movements
653
00:35:38,983 --> 00:35:42,986
and new combinations
through trial and error.
654
00:35:42,987 --> 00:35:47,656
Going from sitting to jumping
is a highly complex movement.
655
00:35:47,657 --> 00:35:52,027
That represents a complex
calculation.
656
00:35:52,028 --> 00:35:53,629
You start
with simple calculation,
657
00:35:53,630 --> 00:35:56,665
maybe an addition,
maybe a small subtraction.
658
00:35:56,666 --> 00:35:58,768
If you could do multiplication,
you can an actually
659
00:35:58,769 --> 00:36:01,237
do better than than just poor
adders and subtractors.
660
00:36:01,238 --> 00:36:03,408
Then somebody doing
square roots or logarithms
661
00:36:03,409 --> 00:36:05,040
or integrals would dominate
662
00:36:05,041 --> 00:36:08,812
over those that are just
the pure multipliers.
663
00:36:08,813 --> 00:36:12,783
Freeman: The red avidians look
like they're going to take over.
664
00:36:12,784 --> 00:36:16,386
But then yellow stands up
and executes a new,
665
00:36:16,387 --> 00:36:19,522
highly complex
jumping Jack move.
666
00:36:19,523 --> 00:36:21,290
Suddenly, yellow starts
667
00:36:21,291 --> 00:36:24,028
replicating faster
than the other colors.
668
00:36:26,630 --> 00:36:28,531
Adami: Very quickly, you'll see
a yellow type taking over,
669
00:36:28,532 --> 00:36:30,165
which then is followed
by a red type
670
00:36:30,166 --> 00:36:31,433
and then an orange type.
671
00:36:31,434 --> 00:36:33,837
And you'll see
many different colors emerge,
672
00:36:33,838 --> 00:36:36,440
take over,
and then go extinct again
673
00:36:36,441 --> 00:36:39,408
in a long, long period
of evolution.
674
00:36:39,409 --> 00:36:42,844
Freeman: Studying avidians makes
Chris feel confident that,
675
00:36:42,845 --> 00:36:46,716
if digital aliens
are hiding inside our networks,
676
00:36:46,717 --> 00:36:49,018
he'll be able to find them.
677
00:36:49,019 --> 00:36:52,254
He's found
a telltale signature of life,
678
00:36:52,255 --> 00:36:55,158
whether it's biological
or digital.
679
00:36:57,594 --> 00:36:59,028
Like all life forms,
680
00:36:59,029 --> 00:37:03,166
avidians are born with a finite
set of instructions.
681
00:37:03,167 --> 00:37:07,470
If Chris removes the rewards
that cause avidians to evolve,
682
00:37:07,471 --> 00:37:08,840
then each instruction
683
00:37:08,841 --> 00:37:12,175
will be used
at roughly the same frequency.
684
00:37:12,176 --> 00:37:14,644
But living avidians
find certain instructions
685
00:37:14,645 --> 00:37:18,780
more valuable than others
and use them far more often.
686
00:37:18,781 --> 00:37:22,318
That is Chris' signature
of life.
687
00:37:22,319 --> 00:37:25,588
Biological life
has an equivalent signature.
688
00:37:25,589 --> 00:37:28,659
The pattern of amino acids
used in our bodies
689
00:37:28,660 --> 00:37:30,726
is very different
from the random pattern
690
00:37:30,727 --> 00:37:32,496
in nonliving matter.
691
00:37:35,966 --> 00:37:37,400
But could aliens
692
00:37:37,401 --> 00:37:41,772
be even closer to us
than inside our technology?
693
00:37:44,808 --> 00:37:47,776
This physicist believes
an endless variety of aliens
694
00:37:47,777 --> 00:37:49,845
may be only a fraction
of an inch
695
00:37:49,846 --> 00:37:52,882
away from every part
of our world
696
00:37:52,883 --> 00:37:56,120
but could remain forever
out of reach.
697
00:38:03,200 --> 00:38:07,069
We assume that, if alien life
is already on earth,
698
00:38:07,070 --> 00:38:10,505
it had to have traveled here
from somewhere else.
699
00:38:10,506 --> 00:38:14,210
Whether primitive microbes
or advanced beings,
700
00:38:14,211 --> 00:38:19,114
the assumption is they had
to cover vast distances.
701
00:38:19,115 --> 00:38:23,920
But what if aliens have always
been right next to us,
702
00:38:23,921 --> 00:38:27,325
living on a different plane
of reality?
703
00:38:36,233 --> 00:38:39,168
Theoretical physicist
Alejandro Jenkins
704
00:38:39,169 --> 00:38:42,471
is constantly amazed
by the diversity of life
705
00:38:42,472 --> 00:38:46,107
in his native Costa Rica.
706
00:38:46,108 --> 00:38:49,045
But he's noticed that
the seemingly endless variety
707
00:38:49,046 --> 00:38:50,313
of plants, animals,
708
00:38:50,314 --> 00:38:56,018
and insects tend to cluster
in separate domains.
709
00:38:56,019 --> 00:38:59,422
Think of the difference
between the canopy ecosystem
710
00:38:59,423 --> 00:39:01,790
that you have on the tree tops.
711
00:39:01,791 --> 00:39:03,993
And then there would be
entirely different ecosystem,
712
00:39:03,994 --> 00:39:06,362
um, right here, on ...
On the ... on the beach floor.
713
00:39:06,363 --> 00:39:08,764
Maybe you can also think
of another ecosystem
714
00:39:08,765 --> 00:39:10,534
on the surface of the ocean.
715
00:39:15,604 --> 00:39:18,840
Freeman: Alejandro believes our
universe may be like one
716
00:39:18,841 --> 00:39:20,877
of these ecosystems,
717
00:39:20,878 --> 00:39:24,447
surrounded by an incredible
variety of alien life,
718
00:39:24,448 --> 00:39:26,882
not in nearby star systems,
719
00:39:26,883 --> 00:39:29,186
but right under our noses.
720
00:39:31,956 --> 00:39:34,456
He thinks the aliens
could be within fractions
721
00:39:34,457 --> 00:39:36,058
of an inch of you,
722
00:39:36,059 --> 00:39:40,228
me, this spider,
everything.
723
00:39:40,229 --> 00:39:45,034
If that's true,
then where exactly are they?
724
00:39:45,035 --> 00:39:47,471
They would be displaced
in another additional dimension
725
00:39:47,472 --> 00:39:50,339
that is not one
of the three dimensions that ...
726
00:39:50,340 --> 00:39:54,009
That we see in everyday life.
727
00:39:54,010 --> 00:39:57,080
Freeman: Many physicists are
convinced there are dimensions
728
00:39:57,081 --> 00:40:02,384
of space and time
that we cannot detect.
729
00:40:02,385 --> 00:40:07,924
Could aliens be living right
among us yet still out of reach?
730
00:40:07,925 --> 00:40:10,060
Jenkins: It's hard to think in terms
of more than three dimensions.
731
00:40:10,061 --> 00:40:12,562
So let's suppose that instead of
living in three dimensions,
732
00:40:12,563 --> 00:40:13,797
we lived in two.
733
00:40:13,798 --> 00:40:16,632
So, uh, the surface
of a ... of a playing card
734
00:40:16,633 --> 00:40:17,933
is two dimensional.
735
00:40:17,934 --> 00:40:21,203
But if you have a ...
An additional third dimension,
736
00:40:21,204 --> 00:40:25,507
you can stack as many cards
as you want.
737
00:40:25,508 --> 00:40:27,210
So I can have this card,
738
00:40:27,211 --> 00:40:28,712
but right ... right below it,
739
00:40:28,713 --> 00:40:31,080
I can have a different one
and so forth.
740
00:40:31,081 --> 00:40:33,817
So perhaps our world,
our universe,
741
00:40:33,818 --> 00:40:36,618
is just one particular slice
742
00:40:36,619 --> 00:40:39,955
through that higher dimensional
space.
743
00:40:39,956 --> 00:40:41,991
You would have to move
only a very tiny distance
744
00:40:41,992 --> 00:40:45,527
in this other additional
direction in order to get there.
745
00:40:45,528 --> 00:40:46,996
Freeman:
Alejandro believes the life
746
00:40:46,997 --> 00:40:50,266
that may exist in these
extra-dimensional universes
747
00:40:50,267 --> 00:40:54,203
could be in a form
that's hard for us to recognize.
748
00:40:54,204 --> 00:40:56,906
We would expect on ... on ...
On theoretical grounds
749
00:40:56,907 --> 00:40:59,741
that a lot of these other
universes would have
750
00:40:59,742 --> 00:41:02,043
different matter contents
and different kinds of ...
751
00:41:02,044 --> 00:41:03,846
Of forces between ...
752
00:41:03,847 --> 00:41:05,748
Between the particle,
upon the matter.
753
00:41:05,749 --> 00:41:07,650
Perhaps in some cases,
even though the forces
754
00:41:07,651 --> 00:41:09,685
are different, uh,
755
00:41:09,686 --> 00:41:12,722
you would still be able
to get a form of life.
756
00:41:15,291 --> 00:41:18,027
Freeman: In this wild section
of Costa Rica,
757
00:41:18,028 --> 00:41:20,596
most creatures in one ecosystem
758
00:41:20,597 --> 00:41:25,935
are unaware the living things
in an adjacent ecosystem exist.
759
00:41:25,936 --> 00:41:28,471
Jenkins:
What we have here is a line
760
00:41:28,472 --> 00:41:31,840
of ants that's carrying leaves
back to its nest.
761
00:41:31,841 --> 00:41:34,743
And I imagine that,
as they move down the trunk,
762
00:41:34,744 --> 00:41:36,179
they're only aware of the fact
763
00:41:36,180 --> 00:41:39,382
that they can move up or down
to their left or to their right.
764
00:41:39,383 --> 00:41:41,984
And we know that there's
another dimension
765
00:41:41,985 --> 00:41:44,254
in which the ant cannot move.
766
00:41:44,255 --> 00:41:45,888
It's not like they're butterfly.
767
00:41:45,889 --> 00:41:48,523
Cannot fly away
in that direction.
768
00:41:48,524 --> 00:41:50,859
So maybe they're not aware of
the fact that there's something
769
00:41:50,860 --> 00:41:53,094
else out there.
770
00:41:53,095 --> 00:41:55,230
Freeman:
We might be like the ants,
771
00:41:55,231 --> 00:41:59,168
unable to see other universes
around us.
772
00:41:59,169 --> 00:42:03,538
Could we ever find another
dimension or even travel there?
773
00:42:03,539 --> 00:42:06,476
Alejandro thinks probably not.
774
00:42:06,477 --> 00:42:07,911
It would seem
like we would never be able
775
00:42:07,912 --> 00:42:09,279
to see those other universes
776
00:42:09,280 --> 00:42:13,316
because light would not be able
to cross that divide.
777
00:42:16,887 --> 00:42:19,422
The old saying
about the search for aliens
778
00:42:19,423 --> 00:42:23,659
was, "the truth is out there."
779
00:42:23,660 --> 00:42:28,031
Well, there's a good chance
that they're also in here.
780
00:42:28,032 --> 00:42:30,732
When we discover aliens, will we
781
00:42:30,733 --> 00:42:34,904
also discover a completely new
concept of life, consciousness,
782
00:42:34,905 --> 00:42:36,739
and intelligence?
783
00:42:36,740 --> 00:42:38,775
I certainly hope so.
784
00:42:38,776 --> 00:42:40,976
The only thing
we really know for sure
785
00:42:40,977 --> 00:42:43,813
is that our civilization
is just a tiny speck
786
00:42:43,814 --> 00:42:46,148
in the greater scheme of things.
787
00:42:46,149 --> 00:42:48,484
And we'll never stop wondering
788
00:42:48,485 --> 00:42:52,522
who else might share
this universe with us.
789
00:42:52,572 --> 00:42:57,122
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