[music playing] NARRATOR: Are we
alone in the universe? Are we the only ones
who look up at the stars and wonder, is
anybody out there? Today scientists quest for
the answer in different ways, some with massive
radio telescopes, some with interplanetary
and interstellar probes. If we find extraterrestrial
life, what will it look like? Soft and squishy? Or will the first
aliens we contact simply be self-replicating machines? Their biological creators having
died off millions of years ago. Some of the top
scientists in the world probe for answers in
the search for ET. [music playing] It is the question that has
kept many people awake at night, staring at the stars,
pondering the possibilities. In a galaxy filled
with a billion stars, in a universe filled with
a hundred billion galaxies, are we alone? The incredible vastness
of the universe is difficult to comprehend, but
here's a way to consider it. If you were to shrink the sun
down to the size of a marble and put it on a sidewalk
in Downtown Manhattan, the Earth would be a
pinprick about 4 feet away. Mars would be 2
feet beyond that. The nearest other star
where we might hope to find intelligent
life, Alpha Centauri, would not be 10
or 100 feet away. It would be in Washington,
DC, 230 miles distant. And another star might be
as much as 7,000 miles away in Rio de Janeiro. But if we ever did
chance upon voyagers from these distant points
in the cosmos, what would they look like? Would they be basically
the same as us? Would they be
fundamentally different? Could they be perhaps
so strange and unusual that they are unlike anything
we ever dreamed or dreaded could exist? Many believe the quest
for extraterrestrial life must really begin with
intense scrutiny of how terrestrial life, life on
Earth, might have begun. And in the early
1950s, two chemists at the University of Chicago
advanced understanding of life's basic
chemistry dramatically. Nobel laureate chemist Harold
Urey and graduate student Stanley L. Miller concocted
a batch of primordial soup. They injected methane,
ammonia, hydrogen, and water into a closed system of
glass bulbs and tubes. These chemicals are thought
to have been commonplace on early Earth. TOM SPILKER: If you put all of
these things into a container and supply some form of energy
to do some kind of reactions, what do they make? What kind of reactions go on? NARRATOR: Miller
and Urey energized the mix with electrical
sparks to simulate lightning. The results were,
well, electrifying. TOM SPILKER: They
got a brown sludge on the walls of their chamber. And when they started
analyzing that brown sludge, there were lots of
organic materials in it. And some of them are
more amino acids. Some of them are precursors, the
building blocks for proteins. NARRATOR: Proteins, of course,
are in turn the building blocks for life. The Miller-Urey experiment
had demonstrated that the precursors
of living organisms could have gotten their start
from a chemical reaction. And such reactions
aren't limited to Earth. Methane, ammonia,
hydrogen, and water are plentiful on
other cosmic bodies within our own solar
system, and, many scientists believe, throughout
the universe. Indeed, noted
astronomer Carl Sagan, speaking of the
Miller-Urey test, stated that no other single
experiment had done more to convince scientists
that life is likely abundant in the cosmos. But the presence
of water was key. Such a chemical
reaction could not have taken place without it. ADAM SHOWMAN: Water is very good
at dissolving materials, much better than many other liquids. And so you can dissolve all
sorts of nutrients and chemical products, things that can
act as catalysts, things that go through the chemical
reactions of life. So water is an excellent
liquid for storing all those chemicals. NARRATOR: On Earth, where
liquid water exists, no matter how extreme the environment,
some form of life also resides. It resides at ocean
depths so great, sunlight cannot reach them. It resides in damp,
rocky crevices miles beneath the Earth's surface. And it even resides in
the extreme salinity of an ancient California lake
with a salt content above 10%. That's three times the
percent of salt in the ocean. But life on Earth
also needs carbon, which was, in fact,
the primary substance generated by the
Miller-Urey experiment. All life forms, as we know them,
consist in large part of carbon molecules. ADAM SHOWMAN: Life needs
some sort of ability to create long molecules
that can store information. So carbon is amazing at
building long molecules. So for example, the DNA molecule
is sort of a billion base pairs long. If you stretched out
a single DNA molecule from one of your cells,
it would be a yard long from a single one of
your trillions of cells. And so you need something that
can store the absolutely huge amount of information
that it takes to build a creature like a
lion or a human or a tree. NARRATOR: But if life is taken
hold elsewhere in our galaxy or beyond, would these
conditions necessarily hold true? Would extraterrestrial life
be water and carbon-based? Would DNA shape
intelligent life? And would the aliens
look anything like us? Maybe they would look
a little bit like us, but that would be very,
very coincidental. I mean, I just saw,
you know, a ground squirrel running behind
a bush over here, and he inhabits the
same planet I do. He's got DNA. Probably 70% of his DNA
is the same as mine. He doesn't look like me. So why would the
aliens look like me? You know, they
probably wouldn't. NARRATOR: A scientist
who has spent time pondering such
questions and rendering speculative alien forms is Dr.
Robert Hurt of the California Institute of Technology. Hurt is a
visualization scientist who uses data returned by
the Spitzer Space Telescope to render images of deep
space objects and processes. To try and find the best
visual ways of explaining complex, technical concepts
but, you know, through imagery. The planets that are being
studied around the stars, the ways that stars
and nebula form, processes that's
going on galaxies, and the distant
universe, all the way out to the edge of the Big Bang. [explosion] NARRATOR: But for
this program, Dr. Hurt has agreed to use known
scientific data to render a speculative alien life form. For his alien world, he's
chosen Jupiter, a real challenge since Jupiter is essentially
a giant gas ball. ROBERT HURT: Now here we have
a place where there is no land to speak of. The atmosphere is made primarily
of hydrogen and helium gas, though it's rich with
organic compounds. And as you get deeper
into the atmosphere, it gets warmer and
much higher pressures. So as a kind of thought
experiment almost, it was posed, what do
you imagine living in an environment like that? NARRATOR: Referencing the only
known model for life, living organisms on Earth,
Hurt began by asking what does life on Earth need. ROBERT HURT: You need
source of energy. You need the chemicals that
life on Earth needs to build, you know, the materials
that it's constructed from. [music playing] NARRATOR: On Jupiter, a
primary source of energy is faint radiation from
the sun, striking the top of the planet's atmosphere. And the only known source
of chemicals for use as building blocks for life are
the organic compounds swirling in the Jovian cloud blanket. In considering a potential life
form that could take advantage of both long-term, Dr. Hurt
remembered an idea originally postulated by Carl Sagan in
the 1970s, the notion of a sort of living gas balloon. Such a creature could remain
aloft in Jupiter's atmosphere indefinitely. ROBERT HURT: After this
is a problem in Jupiter that Jupiter's atmosphere is
already made of the lightest gas we know of, hydrogen. So
you can't really make it lighter than a hydrogen balloon. So if you want a balloon to
be able to float in Jupiter's atmosphere, it actually has
to be a hot air balloon. NARRATOR: Hurt is invented an
extraterrestrial organism that is really more
plant than animal, a balloon-like plant inflated
and kept buoyant by hot air. Now it's going to be really
expensive in terms of biology to generate that heat itself. So instead, if we imagine a
creature that has a very dark skin, very thin that
allows solar radiation to heat the gases
inside, you might be able to create something
that will levitate at least during
the daylight hours just by absorbing
solar radiation. NARRATOR: At night, the plant
would lose its heat source, but Dr. Hurt has allowed for
this problem in the creature's design. ROBERT HURT: It also has a shape
that is well-adapted to act kind of like a parachute that
can ride thermals when it's not able to heat its own gases
and float like a balloon. So in the nighttime, it
might sink down lower into the atmosphere. But by finding thermals,
it can ride this up, like a glider almost. NARRATOR: Time spent
at lower altitudes would actually be
beneficial for the creature. It's here that its
food is most plentiful. ROBERT HURT: I've given it
a kind of arrowroot system that hangs in the bottom. When it sinks into the lower
parts of the atmosphere, it can screen out, pull up some
of those organic compounds we know exist in the
atmosphere of Jupiter. NARRATOR: Of course, Dr. Hurt's
creation of the Jovian balloon plant represents nothing more
than an entertaining exercise in extreme, though
science-based, speculation. But the possibility
that some form of life might actually now exist
on other cosmic bodies in our solar system is very
real to many astrobiologists and geologists. And one such body
is right next door to Jupiter, the ice-covered
Jovian moon, Europa. 370 million miles from Earth,
orbiting the giant gas planet Jupiter, is the
most likely harbor for extraterrestrial life
in our solar system, Europa. It's an ice-covered ball,
about the size of our moon, about 1/4 the size of Earth. Scientists believe
the ice on Europa is covering a global
ocean of liquid water. A convincing indicator is
that Europa is a conductor of electromagnetic energy. It conducts the magnetic
field generated by Jupiter. This conduction
is the signature, or we think it's the signature,
of salty water inside Europa. Its believed that the
water layer on Europa might be as much
as 100 miles thick. Now remember Europa is similar
in size to the Earth's moon. So that means that even
though it's a smaller body, it actually has twice the
amount of liquid water of all of the oceans on
Earth put together. NARRATOR: And of
course, liquid water is what makes life
possible on Earth. So scientists who make it
their business to quest for extraterrestrial
life are keenly focused on the study of Europa. But how could liquid water,
which freezes at temperatures below 32 degrees Fahrenheit,
exist on a moon five times as far away from the
sun as the Earth? Europa orbits Jupiter in
an elliptical pattern. Sometimes it's close to
Jupiter, and sometimes it's farther away. When it's close
to Jupiter, it gets stretched by Jupiter's gravity. It's an effect
that we call tides. And when it gets further
away, it's stretched less. So it means that the body of
Europa is continually worked. NARRATOR: Friction caused by
this stretching generates heat, just as a rubber ball heats up
when it's squeezed repeatedly. At the planetary
scale, this process is called tidal heating. And it creates enough
heat, possibly, to keep H2O miles below
the surface of Europa in liquid form. It also appears that this
stretching causes fractures in the Jovian moon's icy crust. RICHARD GREENBERG:
Imagine if you're trying to change the shape
of an egg, what would happen to the shell? The shell would crack. And so when we look at
the surface of Europa, we see lines all over the place,
which are almost certainly marking the locations of cracks. NARRATOR: The cracks appear
to open and close frequently. And the potential
for these cracks to allow subsurface water
to interact with the surface has important implications
for the possibility of life on Europa. RICHARD GREENBERG:
Water from the ocean is going to rush
up into the crack. When it rushes up, it's going
to freeze, start to freeze. A few hours later
when the crack closes, it's going to squeeze that
slush up to the surface. And so wherever we see
these lines on Europa, there are double ridges,
one ridge lining along each side of the crack. NARRATOR: Most of the
water moved out sloshes back down out of the
crack to the ocean below. It's likely to carry with
it some of the building blocks for life that have
seeped down from the surface. The top of Europa's
ice layer holds oxygen. It's been separated
from the H2O in the ice by charged particles in
Jupiter's magnetic field. RICHARD GREENBERG: In addition,
the surface of Europa likely has organic compounds
that come down from comets and bits of comets. So again, the surface
has another ingredient that's important for life. NARRATOR: Dr. Richard Greenberg
of the University of Arizona has graphically depicted how
potential life forms might take advantage of the ecosystem
created by a crack in Europa's icy crust. RICHARD GREENBERG: Although
the outer a few inches would not be a good place
for life to live because of radiation, once you
go down just a few feet, life would be safe
from radiation. And also, we'd get enough
sunlight for photosynthesis. So you could have an
organism at that level that photosynthesizes, and it would
be connected to the ocean by this tidal water that
rushes up and down every day. NARRATOR: A day on
Europa is much longer than a day on Earth,
about 3 and 1/2 times the length of an Earth day,
time for mobile organisms to venture into the fissure. RICHARD GREENBERG: You could
imagine other organisms that grasp onto the walls
of these cracks and just exploit the flow of
ocean water coming past them every day. NARRATOR: Even mollusk-like
or jellyfish-like creatures might rise with the
water into the cracks to take in fresh nutrients
from the surface. Life in Europa's
ice-covered oceans may also draw energy and
nutrients from a place other than the icy surface. It's possible that residual
heat at Europa's core has resulted in deep
sea hydrothermal vents. On Earth, such vents host
multiple forms of exotic life. ADAM SHOWMAN: What happens
is that reducing water that's very hot and has
lots of heavy metals comes out through
the groundwater and is injected into
the ocean itself. There's a huge gradient in
the chemical composition that life can feed off of. This chemical source of
energy allows huge populations of bacteria and other very
small lifeforms to exist. There's a whole ecosystem,
a whole food chain on top of that
leading up to fish and various worms that
thrives in those locations. NARRATOR: In recent years, talk
has arisen of sending a lander to Europa that could penetrate
the ice and probe for life, like Europa expert
Richard Greenberg believes that a lander might
uncover signs of life without penetrating the ice. RICHARD GREENBERG: If we
send spacecraft to Europa to look for life, it might
be pretty easy to find it, easier than people
have realized. Most planning has considered
how do we get through this miles of ice to get down to the
ocean, how do you drill through or melt your way through. It may not be necessary. If you can land in a place
where liquid or ice has come up from the ocean
recently, you might find signs of organisms in that ice. Or if you land really smart
and find an active place, you might actually
be able to sample real, fresh oceanic water. NARRATOR: The risk in
that case, some feel, would be contaminating
the icy moon. RICHARD GREENBERG: If we had
microorganisms that stowed away on a spacecraft that landed
on the surface of Europa and those microorganisms found
their way into the liquid water of Europa, we might
later discover life on Europa that was life
that we had sent there. NARRATOR: But elsewhere
in our solar system, on another distant moon, earthly
contamination isn't a danger. Life here would
simply be too exotic. Since 2004, a NASA probe dubbed
Cassini-Huygens has orbited Saturn, making multiple
flybys of Saturn's largest moon, Titan. Titan is an enormous planetary
body, the second largest moon in the solar system, 50%
larger than the Earth's moon. If it wasn't in
orbit around Saturn, Titan would be a planet
in its own right. But most impressive of all,
Titan, many scientists believe, could now or at some
point in the future be an abode for life. ROSALY LOPES: The geology
is very much like Earth. All the processes that we have
on Earth, wind, erosion, lakes, volcanism, mountain building,
impact craters, we find them all on Titan. And so Titan is very
rich in terms of geology. NARRATOR: But at 840
million miles from the sun, six times farther than Earth,
Titan is beyond freezing. The mean temperature
on its surface is almost 300 degrees
below zero Fahrenheit. It is so cold, and water
on the surface of Titan is frozen to such an extreme
state it behaves like rock. The rocks in this blurry photo
taken by the Huygens lander are, in fact, water. It is so cold that hydrocarbons
that are gases on Earth, such as methane and ethane,
are in a liquid state on the surface of Titan. The Cassini flybys
have spotted them. TOM SPILKER: We're
seeing a lot of what looks like organic
materials on the surface, and we're seeing large
bodies of liquid, but it's not liquid water. It's liquid methane with
possibly some ethane dissolved in it. There are huge lakes on the size
of Great Lakes or small seas. NARRATOR: Astrobiologists
are beginning to entertain the notion that
organisms could have developed in those lakes. Life could be
very, very exotic. We have been thinking of life
in terms of water and liquid water. But could there be life
in liquid hydrocarbons? Perhaps. Life on Earth exists in
some very difficult places that you wouldn't
expect to find life, and we call this
organisms extremophiles. That's because they can live
under extreme conditions. For example, here on Mono
Lake, very alkaline lake, and yet extremophiles have
been found living here. NARRATOR: Another possibility
is that life formed much earlier in Titan's history when
a great deal of heat from the initial formation
of the moon remained. At that time,
conditions on Titan would have been very similar
to those on primordial Earth. TOM SPILKER: There was
a lot of water there. There's a lot of nitrogen,
a lot of other things. So you've got warm,
water, nitrogen, carbon. And we think some of these
chemical processes that went on on Earth to start generating
the biological-- prebiological materials that later on would be
incorporated into life that may have started on Titan also
with the same kind of chemicals present in a warm environment. NARRATOR: Something is possible
that if Titan's core is still warm, microbial life, at
least, might still be present deep below the moon's surface. Living organisms have been found
thriving in damp rock crevices 2 and 3 miles below the
surface of the Earth. TOM SPILKER: Now if you
go deep down into Titan-- and when I say deep down, I'm
talking about 50 kilometers or 100 kilometers, maybe even a
couple of hundred kilometers-- just like Earth, as you go
downward, it gets warmer. And it looks like,
probably, at Titan, there are materials
mixed in with the water, such as ammonia, that
can act as antifreeze. And we know this liquid
water is a wonderful medium for all kinds of
chemical reactions, including the reactions
that generate amino acids and other prebiotic chemicals. NARRATOR: At present
though, close observation of Titan's surface is limited. The moon is cloaked in a
dense atmosphere of nitrogen and methane. The Cassini probe is equipped
with an infrared imager, but photos shot in
a visible wavelength are often much more
useful to analysts. TOM SPILKER: You have
to somehow get around this opaque atmosphere
that's obscuring your view of the surface. But to really see what's
going on on the surface and notably to get a really firm
idea of what is the composition of all these different things
that we see on the surface, it turns out we're going to
have to go down there close to do that. NARRATOR: The Huygens lander
has touched down on the moon and sent back images, but
the lander is not mobile. ROSALY LOPES: When you land
on the planet, of course, that brings tremendous
advance in terms of science, but it's only one spot. So how much of the
Earth would you know if you land it on the
Sahara Desert, for example? You wouldn't see the kind
of life that we see here. NARRATOR: One possibility
for exploring vast expanses of the Titan's surface would be
to use a craft that works much like a hot air balloon on Earth. NASA's Jet Propulsion Laboratory
is developing a balloon craft that would carry both imaging
gear and equipment for studying the Titan atmosphere. Engineers consider a balloon
the most stable platform for such a mission. TOM SPILKER: If a balloon
loses its electronic control for several hours, no big deal. You can have something on board
that senses that and tells the balloon, OK, close
your ascent-descent valve and just go to a safe altitude
and sit there until you get further instructions. NARRATOR: But while complex
missions to far off moons within our solar system
are exhilarating and often return great scientific
insight, the promise of discovering more
than primordial extraterrestrial
life is slim at best. The hope of finding intelligent,
technology-producing life seems greatest when we look
beyond our solar system, to neighboring stars. While we may never encounter
such life, for most scientists who study the universe, the
notion that it exists somewhere makes perfect sense. RICHARD GREENBERG:
Life tends to evolve to become more successful. And one of the things that
makes organisms successful, it seems on Earth, is
to become intelligent. So it seems quite
plausible to me that there are creatures that
have some sort of intelligence on other planets. TOM SPILKER: If one of those
starts out a billion years before our solar
system started out and it takes that one a
billion years longer to get to that point, well, they're
at the right time right now. NARRATOR: And at radio telescope
installations across the globe, we earthlings are
listening for them. Oho, wohooo! Howdy doody, boys and girls. NARRATOR: We have
been sending signals into the void for decades. Every broadcast on this
planet, every FM radio wave, every television transmission
goes out into the infinite for all of eternity. Could anybody out
there be listening? And how long would it
take our radio signals to cover the distance? PUPPET: Howdy doody,
boys and girls. NARRATOR: Let's
consider once again the analogy where our sun
is a marble on a sidewalk in Downtown Manhattan. Alpha Centauri, the
closest other star, is a marble on a sidewalk
in Washington, DC. And a more distant star is
a marble in Rio de Janeiro. A rocket launching from Earth,
the marble in Manhattan, would take 75,000 years to
reach Alpha Centauri, the marble in DC. That same rocket would
take two million years to reach the marble
in Rio, a star 100 million light years away. Fortunately, radio signals
are much faster than rockets. They travel at the
speed of light. So rather than
taking 75,000 years, a signal traveling from
the marble in Manhattan to the marble in DC would
only take 4 and 1/2 years. A signal traveling from
the marble in Manhattan to the marble at Rio would take
100 years to make the journey. Some of our earliest
transmissions might now be getting close. PUPPET: Howdy doody,
boys and girls. NARRATOR: But what
about the reverse? Could intelligent
alien civilizations be sending pings toward Earth
to see if anyone is at home? Scientists on Earth are
listening using technology originally developed
for studying distant cosmic phenomena,
like exploding stars. SETH SHOSTAK: Many phenomena
produce radio waves. And by studying the
radio waves, you can also learn something about,
you know, what's out there and how it works. So using radio antennas
to study the universe, that's an idea that goes back
to before the Second World War. NARRATOR: The huge radio
antennas used today called radio telescopes are
so advanced and so incredibly sensitive, they can
easily detect the energy of a flea hopping. SETH SHOSTAK: You know, they're
just big reflectors, right? So the radio waves that
are coming down and falling on the ground all around us
on the whole Earth after all. Well, some of those radio waves
will fall on these antennas. So they bounce off
that big mirror, then they get focused to a
very sensitive amplifier. And then the signals
are sent by a cables back into a control room
that's right nearby here where they have sensitive receivers
to sort of analyze the radio energy that's coming in. NARRATOR: Dr. Seth Shostak is
a senior astronomer at the SETI Institute in Mountain
View, California. SETI is an acronym that stands
for Search for Extraterrestrial Intelligence. The SETI organization
also uses radio telescopes but not for studying
natural cosmic phenomena. SETH SHOSTAK: The very
same technology can also be used to look for signals that
are made not by nature but by, well, perhaps ET. NARRATOR: And how might
one know the difference? The kind of signal
that we're looking for is what's called a
narrowband signal. That is to say, it's
just the signal that's-- that's at one spot
on the radio dial, that it's at one frequency. That's the indication
that the signal is made by a transmitter,
not made by nature. NARRATOR: Of course, computers
do the listening, not scientists. SETH SHOSTAK: We get these
specialized receivers that do all the listening,
and the computers are monitoring the receivers. So typically, we'll have
receivers that monitor, say, 100 million channels at once. So if the computers see a signal
that looks like it might be extraterrestrial as opposed to
a radar at the local airport or a telecommunication satellite
or something like that, then the computer will
follow up on that signal. If it's beginning to look
like, yeah, you know, this might be the big one, then
it'll call us up and draw it to our attention. So we don't have to sit there
and be bored all the time. NARRATOR: To date, no such
signal has been detected. But the SETI Institute
presses on faithfully. Rightly so in the minds of
many prominent astronomers. Absence of evidence is
not evidence of absence. So we can't say, oh, SETI
hasn't found anything so far, so obviously, there are no
other intelligent civilizations out there. No, we can't say that. And I support their
continuing to look. There are hundreds of
billions of stars in our galaxy and hundreds of billions of
galaxies in the universe. Just by sheer weight of
numbers, I would be surprised if there is not intelligent life
somewhere else in the universe. NARRATOR: With so
many possibilities, how do SETI astronomers
determine exactly where to focus their
telescopes and efforts? SETH SHOSTAK: You want
to pick star systems that have a good chance of maybe
having a planet something like this one so that there is
a greater chance that you have intelligent life. But we don't really know very
much about what kind of planets these stars have, so we just
have a long list, literally, millions of stars relatively
nearby our cosmic backyard, and we just work our
way through them. NARRATOR: And what would
happen if one day a SETI radio telescope picked up a signal
that looked like it could be an alien transmission? One thing you would certainly
do if you picked up a signal is say, look, I'm not going to
believe it till somebody else can see it as well because,
you know, there could be bugs in the software or hardware
that are fooling you here. So what you would do is at the
point where you thought this looks real, you would call
up somebody, another radio observatory where they also
have antennas just like this, and tell them, look, look
at that part of the sky over this range of radio
frequencies, this part of the dial, and see
if you find anything. And if it were confirmed at two
or maybe three observatories, I think at that point, you could
safely go and have your press conference. NARRATOR: But what if
our first contact with ET isn't through radio signals? What if ET arrives in a
form we don't recognize? The first alien delegation
could reach Earth in the form of machines so tiny, human
beings cannot detect them with the naked eye. Step forward. You speak English? We speak every language. NARRATOR: Since the
1950s, at least, science fiction films
have consistently depicted potential alien
beings as human-like. [music playing] MAN: Homo sapiens. Slaves. [music playing] NARRATOR: One
particular alien form has been widely popularized
in recent decades. UFO enthusiasts believe the
US military recovered bodies from crashed alien
spacecraft in the 1950s. These alleged extraterrestrials
are essentially frail, miniature humans
with oversized heads. [music playing] SETH SHOSTAK: Little gray guys
that usually have big eyes, they don't smile a
lot, but they're always sort of soft, squishy,
organic things. Maybe they don't have DNA, but
they're biology, they're alive. [music playing] NARRATOR: It's an
easy anatomical form for human beings to
comprehend and accept. [music playing] SETH SHOSTAK: Is that what
ET would really be like? Maybe. I mean, you know,
it's a good guess. That's what we're like. But on the other hand, I
think that within 100 years, we may invent thinking machines. And if we can do that,
if we ever do that, that meant the aliens might
have done that a long time ago. Keep in mind, the universe is
a lot older than the Earth is, so they've had plenty of time. Hello, Kismet. You wanna talk to me? NARRATOR: While the notion
of thinking machines might sound far-fetched,
some futurists believe such machines are
just around the corner. [music playing] RAY KURZWEIL: We're shrinking
the size of transistors on an integrated circuit. So every two years, we can
put twice as many on a chip. And they run faster
because they're smaller. And this has been
true now for decades. I can carry in my pocket
today computer that is thousands of times more
powerful than the computer that all of us thousands
of students and professors shared when I came
to MIT in the 1960s. NARRATOR: Ray
Kurzweil is convinced that the power and
speed of computers will shortly surpass
that of the human brain. [music playing] RAY KURZWEIL: If you take the
most conservative estimate of the amount of computation
required to simulate the entire human brain, which
is 10 of the 16th calculations per second-- there
are other estimates that are lower than that. Take the most
conservatively-high estimate. We'll have that
for $1,000 by 2020. We'll have it for $1 by 2030. We'll have that
in a supercomputer actually within a few years. NARRATOR: Kurzweil predicts
that in the near future, tiny supercomputers will be
integrated into the human body to bolster some
of its weaknesses. [music playing] RAY KURZWEIL: We've
already started. And there are people walking
around that have computers in their brains that replaced
a portion of their brain like Parkinson's patients. And there are any of these
devices actually can download new software, so you can
download the software to the computer in your brain
from outside the patient. This is today. [music playing] NARRATOR: It doesn't stop there. As technology marches forward,
microscopic computer-driven machines called nanobots
will be capable of performing a wide variety of maintenance
tasks within the human body. RAY KURZWEIL: It wasn't like to
be able to send these devices to the bloodstream, and we'll
have billions of these blood cell sized computers
and little robots inside our bloodstream
that keep us healthy, and they'll be interacting
with our biological neurons. So we got about 2030,
the common man and woman will be part biological,
part non-biological. NARRATOR: But perhaps Kurzweil's
most radical prediction is that computers will
ultimately allow human beings to transcend their biology,
shed their bodies altogether. Computers will scan the
neurological functions of a person's brain and upload
the individual's knowledge, experience, and personality
to a storage device. RAY KURZWEIL: You'd have to in
real-time go inside my brain, probably with
nanobots, blood cell sized scanners inside
the bloodstream and send billions of
them into my brain through the
capillaries, and they would scan all the
different neurons and gather every
detail about me, all the neurotransmitters,
and ion concentrations, and interneuronal connections,
every detail that makes me me. And I think that
will be feasible. That'll take longer, you know. Maybe that's 40 years
from now or more. But we'll get to a point
where you could actually capture every detail
about a person and then recreate
that personality. [music playing] NARRATOR: The implications
are, of course, staggering. Chief among them is the
possibility of immortality. RAY KURZWEIL: You can
back up your files. If the hardware dies, it's
not the end of your files. You just copy them
over to a new machine. The whole personality of your
machine can be preserved. You can make another copy of it. NARRATOR: And the
machines themselves will be intelligent enough to
self-replicate and steadily improve their design. RAY KURZWEIL: We see
self-replication in computers, for example, software virus. That's an entity. It's not physical. It's just a piece of
software, but it's actually able to copy itself, so someone
can put out one software virus. And it's busy copying
itself and then moving through the internet. And pretty soon, it can
be on a billion computers. So that's self-replication. NARRATOR: And of course,
intelligent machines that are both immortal and much
less vulnerable to radiation and other hazards of space
could possibly survive long-term interstellar voyages. It's an argument that leads Ray
Kurzweil and other futurists to believe that our first alien
encounter will more likely be with intelligent machines
than biological creatures. RAY KURZWEIL: Any civilization
intelligent enough to make the chip
here are not going to send big squishy creatures. They're going to
send little nanobots and non-biological systems. And that's what
we're going to do. NARRATOR: Intelligent or
not, biological or not, the discovery of any form
of extraterrestrial life would arguably be the most
profound scientific revelation in the history of
human civilization. Some would even argue it could
have a profoundly positive influence on human interaction. ROBERT HURT: To me, I would
think that this would really change our perspective
as a people. I mean, if nothing else, just to
give us the perspective that we are one species on one
world and a universe in which we are unique
from what we are. And if this doesn't provide
leverage for us to get past some of are foolish
differences, I-- I don't know what will. I think, ultimately, it might
be one of the best things that could happen for us. [music playing] NARRATOR: There's
even the possibility that contact with an
alien civilization wouldn't cause panic in the
streets as some might predict. At the proper
moment, the invasion will be launched
from our platforms. I'm getting out of here. Stay where you are. ROBERT HURT: I think humans are
ready to meet aliens much more than-- than they're
given credit for. I think we're a lot more
flexible and a lot more open to these things. And the idea that-- that
we'll tear ourselves apart and panic and society
would collapse, I think that actually
sells us way short. [music playing] NARRATOR: But what if we
never find the answer? What if we never hear
any alien signals, never meet intelligent species
outside of our own? Silence in its own way would be
an equally profound response. It tells us that life is unique
and that intelligent life is precious. It should be treasured and
protected at all costs. Are we truly alone? It is perhaps the
greatest question that we can ask of the universe. [music playing]
