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NARRATOR:
Humans are natural-born explorers.
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We charge into uncharted territory
and seek out the unknown.
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We've mapped nearly every inch
of Mother Earth...
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...and left tracks on the moon.
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But to set foot on another planet...
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...to travel beyond our solar system...
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...that is a dream for the future.
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A dream that comes to life
in the feature film Interstellar.
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BRAND: We must think not as individuals
but as a species.
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We must confront the reality
of interstellar travel.
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NARRATOR: The film Interstellar deals with the
quest for new worlds and the fate of humanity.
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Sound like the stuff of science fiction?
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Maybe.
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But the foundations of this film
are rooted in real science...
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...thanks to the involvement
of renowned astrophysicist Kip Thorne.
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In Interstellar,
one of the most important features...
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...is the way that the science
is totally embedded in the film.
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There are some wild things in here.
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NARRATOR: Beyond fantasy and fiction,
this is the real science of Interstellar.
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Space travel has been a staple of the movies
from the very beginning...
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...but the feature film Interstellar
has a unique pedigree.
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It was inspired in part
by the work of Kip Thorne...
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...an authority on astrophysics,
gravitational waves...
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...and the warping of space-time.
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He's also an executive producer
on the film.
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In Interstellar, real science was built
into the fabric of the film from the outset.
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The other major players in this film,
they all respected the science...
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...and they worked with me to see
that the science was well incorporated.
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Can you tell me what the easiest definition
of what a singularity is?
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Kip and myself meshed well
in terms of trying to use current thinking...
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...current scientific understanding
to drive the narrative.
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The language we use...
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...is it's a place where the curvature
of space and time gets infinitely high.
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So we're good, okay.
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And we just hope that the research we've done
and the conversations I'd had with Kip...
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...and that Chris had had with Kip
informed the narrative...
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...and that the audience would feel that.
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NOLAN:
Why simply imagine, fantasize...
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...about things that might happen in space
or on an interstellar journey?
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Why not actually look
at, uh, the real science there?
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It's an Indian surveillance drone.
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NARRATOR:
Interstellar takes place in a future...
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...where living conditions on Earth
threaten the survival of humanity.
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BRAND: Your daughter's generation
will be the last to survive on Earth.
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COOPER: Now you need to tell me
what your plan is to save the world.
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BRAND: We're not meant to save the world,
we're meant to leave it.
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One of the things that the film explores is,
do we belong on Earth...
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...and should we be staying on Earth...
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...and if there is anything else out there,
should we be exploring that?
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Here we go.
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NARRATOR: In the film,
the crew seeks a new place to call home.
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A planet that can sustain life.
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Human life.
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-I'm not gonna make it!
-Yes, you are.
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It's an exciting concept
that there may be other worlds out there.
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Well, what are those worlds
and what could they be...
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...and is there a place for us out there?
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NARRATOR:
The search for another Earth...
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...sounds like a job
for the explorers of tomorrow...
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...but it's happening right now.
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Astrophysicist Natalie Batalha
is a passionate planet hunter.
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BATALHA: I think the only way that we're going
to really understand our place in the galaxy...
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...is by looking at this broad picture
and understanding the diversity of all planets.
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Twenty or 30 years ago, we didn't know...
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...of any other planets orbiting normal stars
like our own sun.
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NARRATOR: Natalie has helped
rewrite that story as mission scientist...
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...for NASA's Kepler space telescope.
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BATALHA:
Kepler's objective is very simple.
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It's to determine the fraction of stars
in our galaxy...
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...that harbor potentially habitable
Earth-size planets.
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NARRATOR: And what makes a planet
potentially habitable?
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The one ingredient that we think
is common to all life forms...
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...is this requirement of liquid water.
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So that's why we look for planets
that have rocky surfaces...
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...where water could pool...
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...and that are receiving the right amount
of energy from the star...
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...where the water wouldn't be locked up
in a frozen state because the planet is so cold...
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...nor would it be evaporated away
because the planet is too hot.
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We call it the Goldilocks Zone,
where liquid water could potentially exist.
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NARRATOR:
Launched in 2009, Kepler stared...
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...at one small patch of the Milky Way
for four years straight.
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Compared to stars,
planets are too tiny for Kepler to spot...
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...but it can detect their shadows.
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BATALHA: Every planet orbiting a luminous
object is casting a shadow out into space.
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The Kepler spacecraft makes use
of that fact...
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...waiting for a planet
in its orbit about the star...
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...to pass directly between
the disc of the star and the spacecraft...
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...and the telescope perceives that
as a dimming of light.
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NARRATOR: This simple method
has revealed thousands of exoplanets.
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Planets orbiting other stars in our galaxy.
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What we've learned so far...
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...is that literally every star in the galaxy
has at least one planet.
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There's an amazing diversity
of exoplanets out there...
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...and we've found very exotic worlds.
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Two hundred light-years away,
there is a Saturn-size planet orbiting...
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...not one, but two stars.
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So if you were living
on a world like Kepler-16b...
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...you would see in the sky two stars
rising in the east, setting in the west...
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...continuously changing position
as they orbit one another.
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This is an artist's rendition
of the planet Kepler-10b.
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It's orbiting 23 times closer to its parent star
than Mercury is to our own sun.
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So this star-facing side is just
being blasted by stellar radiation...
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...creating temperatures
in excess of that required to melt iron.
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The planet has an entire hemisphere
larger than the Pacific Ocean...
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...which is an ocean,
but it's not an ocean of water.
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It's an ocean of molten lava.
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NARRATOR:
Not an attractive destination.
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But Kepler recently found us
a possible second home.
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This is an artist's concept
of the Kepler-186 planetary system.
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Five planets orbiting this M-type star...
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...and the outermost planet is Kepler-186f.
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Our first discovery of an Earth-size planet
in the habitable zone of a normal star.
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When I think about Kepler-186f,
I try to imagine it as a real place...
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...because it is a real place.
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We know that it could be rocky,
it's the same size as Earth...
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...so I do imagine a rocky surface.
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We don't know that it has a liquid ocean,
but we can certainly imagine one.
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And then, all of a sudden
in your imagination...
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...you internalize the existence
of this world out there...
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...that there is a place
that could be very, very much like Earth.
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NARRATOR: So when do we set sail
for these distant shores?
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Reality check.
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Kepler-186f is nearly 3 quadrillion miles
from Earth.
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Otherwise put, 500 light-years away.
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That's a journey of 500 years
at the speed of light.
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But no thing can travel as fast as light.
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At best, our spacecrafts
are thousands of times slower.
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Even the spaceships in Interstellar
don't come close.
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BRAND: We need the bravest humans
to find us a new home.
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COOPER: But the nearest star
is over a thousand years away.
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-Hence the bravery.
-Okay.
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NARRATOR: So how do they reach new worlds
beyond our solar system?
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They take a walk on the warp side
of space and time.
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MURPH:
You have no idea when you're coming back.
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AMELIA: Couldn't you have told her
you were going to save the world?
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No.
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I'm coming back.
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NARRATOR: When we journey to a far-off place,
we travel not just in space but also in time...
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...as we move into the future.
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Until about a century ago, scientists believed
that space and time were entirely separate.
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Theoretical physicist Sean Carroll explains
how Albert Einstein overturned that idea.
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CARROLL:
One of Einstein's great insights...
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...was that space and time
were related to each other...
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...where you have space and you have time.
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Einstein says, "There's only one thing
which we call space-time."
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And then he says, "This space-time thing...
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...it's not just the stage
on which all the action plays out.
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It's an actor itself."
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Space-time can change, it can move,
it can bend, and it can warp.
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NARRATOR: Einstein's theory of relativity
states that space-time is like a flexible fabric.
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The objects embedded in it:
The sun, planets, even us, warp that fabric.
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And the consequence of that warping
is what we call gravity.
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The more massive the object,
the more space-time is warped...
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...and the greater the gravity.
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We feel gravity.
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The flexibility of space-time
is harder to grasp on a gut level...
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...but its effects are measurable.
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As Sean demonstrates, the greater the gravity,
the more slowly time flows.
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CARROLL: For example,
if I were on the ground floor with a clock...
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...a super accurate atomic clock...
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...and a twin of mine was up
on the top floor of a building...
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...with an equally accurate atomic clock...
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...if we later on compared them,
mine would have ticked off fewer seconds.
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NARRATOR: On the ground floor,
Sean experiences slightly more gravity...
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...than his twin on the top floor.
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He also experiences slightly less time
than his twin.
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The difference is tiny, but real.
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And there are practical applications.
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CARROLL: For example, the GPS system,
the Global Positioning System...
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...that is a very, very precise set of clocks...
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...on satellites orbiting around the Earth...
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...and that orbit is in a slightly different
gravitational field than we are in down here.
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So the fact that time moves differently
here on the surface of the Earth...
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...than in the satellite orbit,
is very, very important...
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...to getting the GPS to work correctly.
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NARRATOR: Time on a GPS satellite clock
advances faster than a clock on Earth...
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...by about 38 microseconds per day...
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...so the system's computers correct for that.
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Motion also affects our experience
of space-time.
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CARROLL:
The best way to say it is just staying still...
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...means that you experience
the most time that you can.
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Moving around and doing things
means you experience less time.
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NARRATOR: Let's revisit Sean at the wheel
of his car and his twin on a park bench.
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If you move out on your car,
and then you come back...
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...compared to the person
who stayed behind...
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...your clock that you took with you
on that journey...
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...will have experienced a little bit less time
than the one who stayed behind.
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NARRATOR: We normally move too slowly
to notice the effect.
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But if Sean could drive
near the speed of light...
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...he could race across the United States
and back again a million times...
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...and experience less
than a second of time...
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...while the twin he left behind...
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...would endure hours of waiting
for Sean's return.
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In other words, Sean would've traveled
into the future compared to his twin.
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This means space travel may get tricky
in years to come.
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The faster our spaceships,
the greater the gravity fields we encounter...
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...the further out of sync we may become
with those we leave behind.
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COOPER:
So if we find a home, then what?
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Every hour is seven years back on Earth.
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NARRATOR: The relativity of time is the source
of hardship and heartbreak in Interstellar.
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The theory of relativity
is fascinating all by itself...
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...but it immediately becomes
something very emotional...
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...when you talk about
the distances between people.
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You know, we all spend time
away from our families.
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I just thought, what if you could take that
to its logical and very bittersweet extreme?
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NOLAN: For me, it was very exciting
to be able to examine the concept...
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...of the subjective experience of time.
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It's really the first time
I've had an objective structure...
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...around the film saying
that time literally is relative...
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...that we all experience time differently
depending on where we are in the universe.
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NARRATOR: But the warping of space-time
may also provide shortcuts...
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...that could make interstellar travel a snap.
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Wormholes.
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They're a staple of science fiction...
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...but they're based on real science.
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Einstein's relativistic laws
govern the warping of space and time...
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...and they say that wormholes might exist,
they could exist.
218
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So this dates all the way back to 1916.
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CARROLL: A wormhole is a particular way
that space and time can be curved.
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It's like adding a little tube
that connects two parts of space.
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The basic idea is that if you're an ant
and you live on the surface of the apple...
222
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...the surface of the apple
is your entire universe.
223
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You can go around the outside
through the universe itself...
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...or you can go through the wormhole.
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00:14:47,475 --> 00:14:52,146
NARRATOR: But Einstein's equations also
predict that if wormholes do form in nature...
226
00:14:52,313 --> 00:14:54,648
...they may be subatomic in size...
227
00:14:54,815 --> 00:14:58,903
...and exist for only fractions of a second
before closing off.
228
00:15:00,237 --> 00:15:04,283
Theoretically, what would it take
to keep a wormhole open...
229
00:15:04,450 --> 00:15:07,328
...and make it big enough
to accommodate a spaceship?
230
00:15:07,495 --> 00:15:10,873
THORNE: It turns out that in order
to hold a wormhole open...
231
00:15:11,040 --> 00:15:14,835
...so it doesn't crunch off and kill you
when you try to go through...
232
00:15:15,002 --> 00:15:21,634
...that you have to have the wormhole threaded
by a negative mass or negative energy.
233
00:15:21,801 --> 00:15:24,011
Einstein says
mass and energy are equivalent.
234
00:15:24,762 --> 00:15:30,142
NARRATOR: Almost all the forms of matter
we know have positive mass and exert gravity.
235
00:15:31,560 --> 00:15:34,021
Negative mass would exert antigravity...
236
00:15:34,188 --> 00:15:37,900
...and repel the walls of a wormhole
to keep it open.
237
00:15:38,067 --> 00:15:43,405
Strangely, it is true
that negative energy can exist...
238
00:15:43,572 --> 00:15:48,119
...and it's been created in the laboratory,
but only in very tiny amounts.
239
00:15:49,078 --> 00:15:50,746
NARRATOR:
It would take vast quantities...
240
00:15:50,913 --> 00:15:54,416
...to prop open a wormhole
large enough for a spaceship.
241
00:15:55,084 --> 00:15:57,586
But just maybe, in the future...
242
00:15:57,753 --> 00:16:02,550
...engineers will devise
advanced technologies to do just that.
243
00:16:02,716 --> 00:16:06,929
Today it's an educated guess,
maybe I should say a half-educated guess...
244
00:16:07,096 --> 00:16:10,432
...that wormholes cannot exist
in our universe...
245
00:16:10,599 --> 00:16:12,601
...but we're far from sure of that.
246
00:16:12,768 --> 00:16:15,646
CARROLL:
The truth is, we just don't know right now.
247
00:16:15,813 --> 00:16:18,566
We don't understand the laws of physics
well enough to say for sure...
248
00:16:18,732 --> 00:16:20,359
...whether or not wormholes are possible.
249
00:16:21,152 --> 00:16:25,865
NARRATOR: But since they're not impossible,
they're fair game for a filmmaker.
250
00:16:26,031 --> 00:16:29,702
I was very excited about the idea
of focusing on a family...
251
00:16:30,035 --> 00:16:31,620
...who would be the pioneers...
252
00:16:31,787 --> 00:16:36,041
...who would experience some of
the extraordinary features of astrophysics...
253
00:16:36,208 --> 00:16:41,088
...particularly the idea of a wormhole
that would allow us to travel to distant stars.
254
00:16:42,798 --> 00:16:45,342
NARRATOR: To create a wormhole
based on real science...
255
00:16:45,509 --> 00:16:48,762
...Visual Effects supervisor Paul Franklin
turned to Kip Thorne.
256
00:16:50,848 --> 00:16:54,476
FRANKLIN: The popular image
of what a wormhole might look like...
257
00:16:54,643 --> 00:16:56,604
...is literally just a hole in space.
258
00:16:56,770 --> 00:17:00,900
It sits on an invisible surface,
you see stuff sliding down the sides...
259
00:17:01,066 --> 00:17:03,235
...and disappearing down the drain,
as it were.
260
00:17:03,402 --> 00:17:05,988
And right in that first conversation,
Kip showed me an image...
261
00:17:06,155 --> 00:17:08,991
...of that kind of classical fantasy image
of these things...
262
00:17:09,158 --> 00:17:13,495
...and said, "This is all wrong."
Ha, ha. "This is not how it is."
263
00:17:13,829 --> 00:17:17,750
NARRATOR: Kip worked out the scientific
equations that define the wormhole...
264
00:17:17,917 --> 00:17:20,461
...and sent them to Paul's animators
back in London.
265
00:17:20,628 --> 00:17:24,423
THORNE: And so for the movie,
I built a mathematical model wormhole...
266
00:17:24,590 --> 00:17:27,968
...based on Einstein's relativity equations.
267
00:17:28,135 --> 00:17:32,848
Paul, Kip and myself, we discussed,
"Okay, we'll visualize the thing.
268
00:17:33,015 --> 00:17:36,018
We'll simulate the thing
exactly as the calculations say."
269
00:17:36,185 --> 00:17:39,063
And Paul Franklin and his team,
they were thrilled to get algorithms...
270
00:17:39,230 --> 00:17:42,691
...that were the absolute latest,
most interesting and up-to-the-minute.
271
00:17:42,858 --> 00:17:44,235
MAN:
Now we can go to the other one.
272
00:17:44,401 --> 00:17:46,820
The wormhole
is a three-dimensional hole in space.
273
00:17:46,987 --> 00:17:49,949
What do you get if you take a circle
and sweep it out in three dimensions?
274
00:17:50,115 --> 00:17:51,367
You get a sphere.
275
00:17:51,533 --> 00:17:55,746
So the wormhole almost feels like
a crystal ball hanging in space.
276
00:17:58,624 --> 00:18:02,336
THORNE: I don't think anybody had ever
really done this kind of visualization before.
277
00:18:02,503 --> 00:18:03,587
This is really unique.
278
00:18:03,754 --> 00:18:08,300
Uh, first time for me,
as well as for you and the audience.
279
00:18:08,467 --> 00:18:09,551
Absolutely, yes.
280
00:18:12,012 --> 00:18:14,932
NARRATOR: In Interstellar, crew members
take a giant leap of faith...
281
00:18:15,099 --> 00:18:17,393
...when they plunge into a wormhole.
282
00:18:17,559 --> 00:18:20,104
DOYLE: You can't think about your family.
You have to think bigger.
283
00:18:20,479 --> 00:18:24,316
COOPER: I am thinking about my family
and millions of other families.
284
00:18:24,483 --> 00:18:27,486
AMELIA: You might have to decide
between seeing your children again...
285
00:18:27,653 --> 00:18:29,280
...and the future of the human race.
286
00:18:29,947 --> 00:18:33,909
NARRATOR: Beyond the wormhole,
the crew will face a far greater challenge:
287
00:18:34,535 --> 00:18:38,289
To navigate the perils of a black hole.
288
00:18:39,957 --> 00:18:43,752
For a filmmaker, that threat
is full of dramatic possibilities.
289
00:18:45,045 --> 00:18:49,633
NOLAN: When you venture out into a story
about a man against the elements...
290
00:18:49,800 --> 00:18:56,390
...visualizing the threat against our protagonist
become very much more exotic.
291
00:18:56,890 --> 00:19:01,979
Deep, deep space gives you
a very, very fresh approach.
292
00:19:02,855 --> 00:19:05,691
NARRATOR: Black holes were predicted
by Einstein's equations...
293
00:19:05,858 --> 00:19:08,652
...but physicists questioned
whether they could really exist.
294
00:19:08,819 --> 00:19:11,322
THORNE:
A black hole is a strange beast.
295
00:19:11,488 --> 00:19:15,034
If this were a black hole,
then instead of a rubber surface...
296
00:19:15,200 --> 00:19:18,412
...it would have a surface
that is made of absolutely nothing...
297
00:19:18,579 --> 00:19:21,248
...except warped space and time.
298
00:19:22,875 --> 00:19:25,544
It's a place where gravity is so strong...
299
00:19:25,711 --> 00:19:29,465
...that if anything falls into the black hole,
it can never get back out.
300
00:19:29,631 --> 00:19:31,967
If you fall in,
you can't send signals back out.
301
00:19:32,134 --> 00:19:34,261
Light can't get out from the interior.
302
00:19:36,055 --> 00:19:38,640
CARROLL: So you might ask,
how would that ever happen?
303
00:19:38,807 --> 00:19:43,437
In outer space, you can get so much mass
together, like in a super-massive star...
304
00:19:43,604 --> 00:19:46,857
...that the gravity just becomes stronger
and stronger and stronger...
305
00:19:47,024 --> 00:19:51,320
...and eventually the pressure
that matter exerts on itself can't keep up.
306
00:19:52,279 --> 00:19:54,907
And everything collapses,
there's a big explosion.
307
00:19:55,074 --> 00:19:59,036
Some of the stuff is blown away,
but the rest of it collapses into a black hole.
308
00:20:00,746 --> 00:20:04,917
NARRATOR: A black hole that spins on its axis
drags the very space around it...
309
00:20:05,084 --> 00:20:09,922
...into a whirling motion
that pulls stars and planets into orbit.
310
00:20:10,089 --> 00:20:14,093
Closer in, gravity increases like a riptide.
311
00:20:14,259 --> 00:20:18,764
At a boundary called the event horizon,
gravity becomes so extreme...
312
00:20:18,931 --> 00:20:22,309
...that nothing can escape being pulled
into the heart of the beast...
313
00:20:22,476 --> 00:20:23,894
...and lost forever.
314
00:20:24,520 --> 00:20:28,357
GHEZ: Black holes are simple,
and yet they have a lot of character.
315
00:20:28,524 --> 00:20:30,526
It's almost like
they can take on personalities.
316
00:20:30,692 --> 00:20:35,030
Um, they can be picky eaters, um,
they can be energetic.
317
00:20:35,197 --> 00:20:36,907
And what you're seeing and describing...
318
00:20:37,074 --> 00:20:39,910
...is really how the black hole
interacts with the environment.
319
00:20:40,869 --> 00:20:43,372
NARRATOR:
UCLA astronomer Andrea Ghez...
320
00:20:43,539 --> 00:20:44,748
Looks like this is Sagi's star.
321
00:20:44,915 --> 00:20:46,875
NARRATOR:
...is an expert on black hole detection.
322
00:20:47,042 --> 00:20:49,044
-Must be this one, right?
-I think it's that one.
323
00:20:49,211 --> 00:20:53,424
NARRATOR: She played a key role investigating
what had long been a scientific hunch.
324
00:20:53,590 --> 00:20:57,010
That a huge black hole
lives at the center of the Milky Way.
325
00:20:57,177 --> 00:20:58,345
It's looking good.
326
00:20:58,512 --> 00:21:01,140
NARRATOR: Astronomers knew
the heart of our galaxy was buzzing...
327
00:21:01,306 --> 00:21:05,144
...with gas, dust and millions of stars.
328
00:21:05,310 --> 00:21:08,647
Some powerful force
appeared to be driving this hubbub.
329
00:21:08,814 --> 00:21:11,191
Could it be a black hole?
330
00:21:12,109 --> 00:21:15,028
Ground telescopes just couldn't produce
sharp images of the region...
331
00:21:16,071 --> 00:21:21,410
...then a technique called adaptive optics
vastly improved the view.
332
00:21:21,577 --> 00:21:25,247
This is what it looks like
before you use advanced technology.
333
00:21:25,747 --> 00:21:26,999
It's a blurry mess...
334
00:21:27,166 --> 00:21:30,836
...and now you can see the individual stars
with adaptive optics turned on.
335
00:21:31,003 --> 00:21:35,132
So each point of light here
is associated with an individual star.
336
00:21:36,592 --> 00:21:41,513
NARRATOR: Andrea put that technique to work
at the Keck Observatory in Hawaii.
337
00:21:42,890 --> 00:21:44,391
GHEZ:
This is a road map.
338
00:21:44,558 --> 00:21:48,187
NARRATOR: And she and her team began
to track the stars at the center of the Milky Way.
339
00:21:48,353 --> 00:21:50,731
GHEZ:
And that's the center of our galaxy.
340
00:21:50,898 --> 00:21:54,067
The very first year that we took the data
was in 1995.
341
00:21:55,110 --> 00:21:59,114
Then we go back to the telescope in '96,
then we take our second image...
342
00:21:59,281 --> 00:22:01,533
...and you have two pictures,
and you can compare them.
343
00:22:03,076 --> 00:22:07,080
NARRATOR: Andrea wanted to see if the stars
were orbiting a single source of gravity...
344
00:22:07,414 --> 00:22:10,209
...but stars can take years
to complete an orbit.
345
00:22:10,834 --> 00:22:13,337
GHEZ: And so it was really important
that we kept going...
346
00:22:13,504 --> 00:22:18,258
...and by 2000 we finally started
to see the star's curve.
347
00:22:18,425 --> 00:22:23,055
In other words, the gravitational influence
of the black hole, um...
348
00:22:23,222 --> 00:22:27,601
...had made those stars
go from straight lines to starting to bend.
349
00:22:27,768 --> 00:22:29,561
Precise enough to see that curvature.
350
00:22:29,728 --> 00:22:34,316
NARRATOR: Year by year,
Andrea and her team built their case.
351
00:22:34,483 --> 00:22:38,570
This animation represents, uh,
20 years of work...
352
00:22:38,737 --> 00:22:45,661
...and it tells you that there is a black hole,
and exactly how massive it is.
353
00:22:45,827 --> 00:22:48,914
NARRATOR: Andrea's painstaking project
revealed a monster...
354
00:22:49,081 --> 00:22:52,334
...with more than 4 million times
the mass of our sun...
355
00:22:52,501 --> 00:22:55,796
...at the center of our Milky Way.
356
00:22:56,421 --> 00:23:00,801
Today, scientists are hunting black holes
with new tools.
357
00:23:00,968 --> 00:23:06,223
Caltech astrophysicist Fiona Harrison
scans the skies with NuSTAR...
358
00:23:06,390 --> 00:23:09,935
...a telescope that looks at the universe
in high-energy x-rays.
359
00:23:11,144 --> 00:23:13,564
HARRISON:
The black hole itself doesn't emit light...
360
00:23:13,730 --> 00:23:16,775
...but dust and gas
falls onto the black holes...
361
00:23:16,942 --> 00:23:22,864
...and in doing so, it heats up,
and it emits x-rays.
362
00:23:23,574 --> 00:23:28,078
NARRATOR: NuSTAR captures black holes
in the process of feasting on matter...
363
00:23:28,245 --> 00:23:31,582
...and the telescope is spotting them
all over the place.
364
00:23:31,957 --> 00:23:36,962
HARRISON: It's really only 10, 20 years ago
that we thought black holes were rare.
365
00:23:37,129 --> 00:23:40,132
We now know that every galaxy,
like our Milky Way...
366
00:23:40,299 --> 00:23:43,093
...has a massive black hole at its heart.
367
00:23:43,594 --> 00:23:48,765
So rather than just being curiosities,
they're actually fundamentally important...
368
00:23:48,932 --> 00:23:51,476
...to why the universe is the way it is.
369
00:23:52,060 --> 00:23:55,564
NARRATOR: So is the Earth at risk
of getting swallowed by a black hole?
370
00:23:56,315 --> 00:23:59,318
HARRISON: Even though we have black holes
sprinkled throughout the galaxy...
371
00:23:59,484 --> 00:24:01,111
...we're in absolutely no danger.
372
00:24:01,278 --> 00:24:05,032
It's a common misconception
that black holes might suck the Earth.
373
00:24:05,198 --> 00:24:08,535
Well, there's no sucking going on,
it's just normal gravity.
374
00:24:09,995 --> 00:24:11,830
It's just when you get very close to it...
375
00:24:11,997 --> 00:24:15,042
...that there's a region
from which light can't even escape...
376
00:24:15,208 --> 00:24:18,045
...and Earth is not gonna do that.
377
00:24:18,920 --> 00:24:20,130
NARRATOR:
But in Interstellar...
378
00:24:20,297 --> 00:24:23,258
...crew members have a precariously close
encounter with a black hole.
379
00:24:23,717 --> 00:24:25,385
COOPER:
Oh, we are not prepared for this.
380
00:24:25,761 --> 00:24:28,388
NARRATOR:
What would the beast look like to them?
381
00:24:28,555 --> 00:24:30,557
One of the things
that Kip was very insistent on...
382
00:24:30,724 --> 00:24:34,436
...is that the black hole, it's spherical,
but it's absolutely black.
383
00:24:34,603 --> 00:24:36,229
It has no surface detail.
384
00:24:36,396 --> 00:24:39,191
Doesn't give shadows
or highlights or anything.
385
00:24:39,358 --> 00:24:42,361
But then early on,
we were talking about accretion disks.
386
00:24:42,778 --> 00:24:47,783
And that gave us a way
to define the spherical shape of the thing.
387
00:24:47,949 --> 00:24:52,329
NARRATOR: A black hole's accretion disk is
made up of gas and dust and magnetic fields...
388
00:24:52,496 --> 00:24:53,914
...that spin at high speeds...
389
00:24:54,414 --> 00:24:57,000
...radiating heat and light.
390
00:24:58,377 --> 00:25:02,422
The black hole's gravity would actually
bend that light like a camera lens...
391
00:25:02,589 --> 00:25:04,341
...in ways that Kip would calculate.
392
00:25:04,800 --> 00:25:09,805
THORNE: I worked out the equations for tracing
light rays traveling around the black hole...
393
00:25:09,971 --> 00:25:15,435
...to see what the disk would look like if you
were in a spacecraft looking at it up close.
394
00:25:15,602 --> 00:25:18,397
NARRATOR: And Paul's team
brought the mathematics to life.
395
00:25:18,563 --> 00:25:22,317
We were really able to use
a very, very accurate representation...
396
00:25:22,484 --> 00:25:26,697
...of the gravitational lens and the effects
of gravity and light around the black hole.
397
00:25:26,863 --> 00:25:32,244
Uh, because what the algorithms gave us
was extremely spectacular.
398
00:25:33,995 --> 00:25:36,248
NARRATOR:
Even Kip was surprised.
399
00:25:36,415 --> 00:25:38,583
You see the disk in front...
400
00:25:38,750 --> 00:25:40,210
...and then when it goes around...
401
00:25:40,377 --> 00:25:44,423
...you see the disk wrap up
around the top of the black hole...
402
00:25:44,589 --> 00:25:46,550
...and wrap around the bottom
of the black hole.
403
00:25:49,720 --> 00:25:51,972
I had guessed
it would look more or less like this...
404
00:25:52,139 --> 00:25:54,766
...but knowing it intellectually
is different than feeling it...
405
00:25:54,933 --> 00:25:57,185
...than absorbing it, than seeing it.
406
00:25:57,853 --> 00:25:59,646
It just blew me away.
407
00:26:00,397 --> 00:26:01,982
NARRATOR:
But this brilliant depiction...
408
00:26:02,149 --> 00:26:05,569
...still can't tell us what happens
in the heart of a black hole...
409
00:26:05,736 --> 00:26:07,487
...beyond the event horizon.
410
00:26:08,905 --> 00:26:14,786
What would happen to an astronaut
daring or crazy enough to dive in feet-first?
411
00:26:14,953 --> 00:26:16,997
THORNE:
In the simplest descriptions of this...
412
00:26:17,164 --> 00:26:20,792
...the descriptions that you will find
in most books that you read...
413
00:26:20,959 --> 00:26:22,919
...you're simply stretched
from head to foot...
414
00:26:23,086 --> 00:26:28,884
...and squeezed from the side by tidal forces,
"spaghettified" is what it often says.
415
00:26:29,384 --> 00:26:32,679
You're spaghettified as you fall in
and you're destroyed.
416
00:26:33,138 --> 00:26:34,973
That's the standard story.
417
00:26:39,603 --> 00:26:42,773
NARRATOR: The truth is,
all the laws of physics that we know...
418
00:26:42,939 --> 00:26:46,193
...break down in the heart of a black hole.
419
00:26:46,359 --> 00:26:50,655
Physicists are still working
on exactly what happens there.
420
00:26:52,073 --> 00:26:53,742
That's the gravity well, though, isn't it?
421
00:26:53,909 --> 00:26:59,122
When we talk to non-physicists,
we will often say it's the gravity well.
422
00:26:59,289 --> 00:27:01,500
So you've been lying to us all these years.
423
00:27:01,666 --> 00:27:04,836
You know how these things go,
there are lies and there are "lies."
424
00:27:05,003 --> 00:27:06,046
I know, but now...
425
00:27:06,463 --> 00:27:11,760
The movie Interstellar deals with physics
that is well-understood, well-established.
426
00:27:11,927 --> 00:27:15,055
It deals with physics
where we make educated guesses...
427
00:27:15,222 --> 00:27:17,933
...and we're almost sure,
but not 100 percent sure of our guesses.
428
00:27:19,059 --> 00:27:22,813
And it deals with physics
at the frontiers of human understanding...
429
00:27:22,979 --> 00:27:24,815
...where we have to speculate...
430
00:27:24,981 --> 00:27:26,817
...and when you get
beyond those frontiers...
431
00:27:26,983 --> 00:27:30,070
...Interstellar works hard to align itself...
432
00:27:30,237 --> 00:27:34,032
...with the best speculations
a scientist could imagine.
433
00:27:34,199 --> 00:27:39,287
We're struggling very hard as filmmakers
to try and explain, uh...
434
00:27:39,454 --> 00:27:42,916
...these scientific concepts,
these sort of abstract ideas...
435
00:27:43,083 --> 00:27:47,212
...in a subjective way and a way that you can
actually experience and feel something about.
436
00:27:48,964 --> 00:27:53,844
NARRATOR: Interstellar mines that gray area
where new ideas percolate...
437
00:27:54,010 --> 00:27:58,890
...and taps deep into questions
about the nature of the universe.
438
00:28:04,396 --> 00:28:08,358
In Interstellar, telescopes on Earth
first detect the presence of a wormhole.
439
00:28:10,068 --> 00:28:14,865
It shows up as a gravitational anomaly
that distorts the view of space.
440
00:28:15,448 --> 00:28:18,785
We made the wormhole
not have all that strong a gravity.
441
00:28:18,952 --> 00:28:20,704
But why the wormhole?
442
00:28:21,079 --> 00:28:24,332
Because then you have a reason
for your trip around it.
443
00:28:24,499 --> 00:28:27,377
I feel uncomfortable with the wormhole
having that much gravity.
444
00:28:27,544 --> 00:28:30,297
THORNE: When I first began working
with Christopher Nolan...
445
00:28:30,463 --> 00:28:33,258
...he wanted a wormhole
that had rather gentle gravity...
446
00:28:33,425 --> 00:28:35,719
...so we discussed
how big the wormhole should be...
447
00:28:35,886 --> 00:28:39,431
...and agreed that it should be
just barely big enough...
448
00:28:39,598 --> 00:28:41,391
...that it could be seen from Earth...
449
00:28:41,558 --> 00:28:44,227
...through the bending of light
around the wormhole...
450
00:28:44,394 --> 00:28:46,563
...by the wormhole's warped space.
451
00:28:46,730 --> 00:28:50,567
NARRATOR: Kip Thorne worked out just
the right gravity for Interstellar's wormhole...
452
00:28:50,984 --> 00:28:55,363
...using equations based on Einstein's theory
of general relativity.
453
00:28:55,530 --> 00:29:01,703
As we've learned, that theory states
that objects warp space-time, creating gravity.
454
00:29:02,537 --> 00:29:06,499
It also predicts that when objects move,
they generate a pulse...
455
00:29:06,666 --> 00:29:10,670
...that propagates through space-time,
a bit like waves through water.
456
00:29:13,632 --> 00:29:18,345
These gravitational waves
have never been directly observed.
457
00:29:18,511 --> 00:29:21,264
They would be small and hard to detect...
458
00:29:21,431 --> 00:29:25,810
...unless they were generated
by a massively violent motion.
459
00:29:27,354 --> 00:29:30,398
Like the birth of the universe.
460
00:29:33,568 --> 00:29:36,446
Physicists developed their big bang theory...
461
00:29:36,613 --> 00:29:41,534
...in part by observing
that today the universe is expanding.
462
00:29:42,744 --> 00:29:48,333
Galaxies are moving away from each other
like raisins in a rising loaf of bread...
463
00:29:49,000 --> 00:29:54,297
...which suggests that in the distant past,
the universe must have been much smaller.
464
00:29:54,464 --> 00:29:59,094
CARROLL: If you wind the movie backwards,
in the past, everything was closer together...
465
00:29:59,260 --> 00:30:04,224
...and you plug that idea
into the equations that Einstein gives us.
466
00:30:04,599 --> 00:30:08,770
And there's a moment, which we now know
was about 14 billion years ago...
467
00:30:08,937 --> 00:30:10,981
...when everything was on top
of everything else...
468
00:30:11,147 --> 00:30:15,819
...when the density of stuff in the universe
was apparently infinitely big.
469
00:30:18,613 --> 00:30:22,909
NARRATOR: Then a powerful force triggered
an expansion of space itself.
470
00:30:23,076 --> 00:30:28,540
Faster than the speed of light,
a theory called cosmic inflation.
471
00:30:28,707 --> 00:30:34,462
And the theory said that this inflation should've
taken fluctuations in the shape of space...
472
00:30:34,629 --> 00:30:37,841
...and amplified them
so they got much stronger.
473
00:30:39,050 --> 00:30:41,386
And they become gravitational waves...
474
00:30:41,553 --> 00:30:45,473
...producing ripples
in the fabric of space and time.
475
00:30:46,641 --> 00:30:48,852
NARRATOR:
If we could detect those ripples today...
476
00:30:49,019 --> 00:30:52,188
...it would help us understand
how the big bang banged.
477
00:30:52,355 --> 00:30:55,066
BOCK: The trick was always
how were we going to measure such a thing.
478
00:30:55,233 --> 00:30:57,110
And that led us to propose and develop...
479
00:30:57,277 --> 00:31:00,155
...this very specialized experiment, um...
480
00:31:00,321 --> 00:31:04,993
...which one of my colleagues
referred to gleefully as a wild-goose chase.
481
00:31:06,202 --> 00:31:10,749
NARRATOR: Caltech physicist Jamie Bock
works in experimental cosmology.
482
00:31:10,915 --> 00:31:14,252
BOCK: Experimental cosmology
is building experiments...
483
00:31:14,419 --> 00:31:16,713
...trying to get back to the dawn of time.
484
00:31:16,880 --> 00:31:17,922
You need a hand with that?
485
00:31:18,089 --> 00:31:19,924
NARRATOR:
The focus of his latest experiment...
486
00:31:20,091 --> 00:31:21,843
...was the oldest light in the universe.
487
00:31:22,177 --> 00:31:26,056
The faint afterglow of the big bang.
488
00:31:26,222 --> 00:31:30,143
Physicists have mapped
this cosmic microwave background...
489
00:31:30,310 --> 00:31:32,520
...across the universe.
490
00:31:33,563 --> 00:31:37,442
If the birth of the universe
produced gravitational waves...
491
00:31:37,609 --> 00:31:39,444
...they would've warped
this primordial light...
492
00:31:39,611 --> 00:31:44,199
...and caused it to be polarized
or curled in a specific direction.
493
00:31:44,365 --> 00:31:46,159
BOCK:
If one could measure the polarization...
494
00:31:46,326 --> 00:31:48,870
...and then not only measure it
but look at its pattern...
495
00:31:49,037 --> 00:31:51,206
...there might be kind of a swirly pattern...
496
00:31:51,372 --> 00:31:54,459
...that would be an indicator
of gravitational waves.
497
00:31:56,002 --> 00:32:00,507
NARRATOR: Jamie and his team designed
a series of small super-sensitive telescopes...
498
00:32:01,633 --> 00:32:04,719
...that they installed
where the skies are crystal clear.
499
00:32:04,886 --> 00:32:06,888
At the South Pole.
500
00:32:07,514 --> 00:32:10,225
BOCK: The South Pole
is the closest we can get to outer space...
501
00:32:10,391 --> 00:32:11,726
...to make our measurements.
502
00:32:14,187 --> 00:32:17,982
NARRATOR: For eight years, the team's
telescopes scanned a patch in the sky...
503
00:32:18,149 --> 00:32:20,610
...measuring minute differences
in the temperature...
504
00:32:20,777 --> 00:32:23,113
...of the cosmic microwave background...
505
00:32:23,279 --> 00:32:24,948
...and a pattern emerged.
506
00:32:25,115 --> 00:32:30,453
BOCK: Our results reported that we see
this swirly pattern of polarization...
507
00:32:30,620 --> 00:32:34,916
...that's consistent with, uh,
what you expect from gravitational waves.
508
00:32:35,708 --> 00:32:39,420
THORNE: So they didn't really see the
gravitational waves from the early universe...
509
00:32:39,587 --> 00:32:43,424
...but they saw this polarization pattern
that was precisely what was predicted...
510
00:32:43,591 --> 00:32:46,094
...except that it was stronger than expected.
511
00:32:46,719 --> 00:32:49,681
Tells us what went on
immediately after the big bang...
512
00:32:49,848 --> 00:32:54,185
...when the universe was a trillionth
of a trillionth of a trillionth of a second old.
513
00:32:54,352 --> 00:32:57,564
So it's seeing almost
the creation of the universe.
514
00:32:58,898 --> 00:33:02,527
NARRATOR: The finding must be confirmed
by other experiments.
515
00:33:02,694 --> 00:33:07,031
If it holds up, this first evidence
for the detection of gravitational waves...
516
00:33:07,198 --> 00:33:11,244
...will deepen our understanding
of the birth of the universe.
517
00:33:12,787 --> 00:33:18,543
And that, by extension,
may help us answer an enduring question:
518
00:33:18,918 --> 00:33:20,879
Can we time travel?
519
00:33:21,045 --> 00:33:23,339
CARROLL:
You know, it's very easy to travel in time.
520
00:33:23,506 --> 00:33:26,551
Yesterday, I've moved forward 24 hours
and here I am.
521
00:33:26,718 --> 00:33:30,096
But that's the only way that it's easy.
It's easy to go into the future.
522
00:33:30,263 --> 00:33:34,517
In fact, it's not just easy, it's inevitable.
We all move into the future over time.
523
00:33:35,268 --> 00:33:38,897
NARRATOR:
But traveling to the past is a different story...
524
00:33:39,230 --> 00:33:42,942
...because space and time
have profoundly different properties.
525
00:33:43,484 --> 00:33:46,738
In space, you can go up, down,
left, right, forward, backward.
526
00:33:48,323 --> 00:33:52,035
NARRATOR: We move freely
through the three dimensions of space.
527
00:33:52,202 --> 00:33:56,956
In time, we experience its one dimension
and a lot less freedom.
528
00:33:57,498 --> 00:34:00,210
CARROLL: Because time has a direction
and space does not.
529
00:34:00,376 --> 00:34:02,212
In time, there's a huge difference...
530
00:34:02,378 --> 00:34:05,548
...between one direction, the future,
and the other direction, the past.
531
00:34:05,715 --> 00:34:09,761
For example, you remember the past,
but you don't remember the future.
532
00:34:09,928 --> 00:34:12,472
You were younger in the past,
we were all younger in the past.
533
00:34:12,639 --> 00:34:15,225
We will all be older. It's all universal to us.
534
00:34:17,894 --> 00:34:21,356
This arrow of time is a little bit mysterious.
535
00:34:21,522 --> 00:34:23,524
We understand the basic underpinnings...
536
00:34:23,691 --> 00:34:27,320
...in a concept called entropy,
the disorderliness of the universe.
537
00:34:28,905 --> 00:34:32,492
NARRATOR: Entropy is the measure
of the disorder in a system.
538
00:34:32,659 --> 00:34:36,037
The more ordered a system,
the lower its entropy.
539
00:34:38,456 --> 00:34:42,210
The more disordered a system,
the higher its entropy.
540
00:34:42,543 --> 00:34:46,965
A classic example of entropy increasing
is just mixing cream into coffee.
541
00:34:47,131 --> 00:34:50,051
When the cream and the coffee are separate,
that's low entropy.
542
00:34:50,218 --> 00:34:52,303
They're organized.
There's the cream, the coffee.
543
00:34:52,470 --> 00:34:55,181
You pour them together,
you let them mix together.
544
00:34:55,515 --> 00:34:58,351
Entropy just goes up.
Things become more and more disorderly.
545
00:35:02,480 --> 00:35:06,150
And this goes all the way back 14 billion years
to the big bang.
546
00:35:07,360 --> 00:35:11,531
NARRATOR: Back then, all the matter in
the universe would have been on top of itself.
547
00:35:11,698 --> 00:35:14,659
Density would have been infinite.
548
00:35:14,826 --> 00:35:17,954
It was the epitome of low entropy.
549
00:35:19,998 --> 00:35:24,168
But entropy has been on the rise
ever since the big bang.
550
00:35:24,544 --> 00:35:27,046
CARROLL: We think, but we haven't
absolutely established...
551
00:35:27,213 --> 00:35:30,925
...that this general tendency
to go from order to disorder...
552
00:35:31,092 --> 00:35:35,221
...is the single reason
why the past is different from the future.
553
00:35:35,388 --> 00:35:39,642
We can't discount in principle
the possibility of visiting the past...
554
00:35:39,809 --> 00:35:43,896
...but all of these weird puzzles
that sort of rub us the wrong way...
555
00:35:44,063 --> 00:35:47,859
...about if I go back into the past
and I give myself a really good idea...
556
00:35:48,026 --> 00:35:51,487
...and then I grow up and become rich off
that idea, where did the idea come from?
557
00:35:51,654 --> 00:35:54,157
These kinds of puzzles would evaporate...
558
00:35:54,324 --> 00:35:57,910
...if we just said, "Well, the laws of physics
don't allow you to visit the past."
559
00:35:58,077 --> 00:36:00,288
So that's probably true.
560
00:36:01,581 --> 00:36:05,752
NARRATOR: To contemplate the mysteries
of space, time and the universe...
561
00:36:05,918 --> 00:36:08,546
...can make a person feel mighty small.
562
00:36:08,713 --> 00:36:13,343
Maybe it's best to lower our sights,
hunker down and focus on planet Earth.
563
00:36:14,385 --> 00:36:18,014
But that's not really an option for humanity
in the long run.
564
00:36:21,559 --> 00:36:25,313
Interstellar depicts a future
where living conditions on Earth are grim.
565
00:36:25,480 --> 00:36:30,234
Our mission does not work if the people
on Earth are dead by the time we pull it off.
566
00:36:30,693 --> 00:36:33,071
NARRATOR:
Failing crops.
567
00:36:33,446 --> 00:36:35,448
Clouds of dust.
568
00:36:37,033 --> 00:36:39,494
Roads clogged with refugees.
569
00:36:39,660 --> 00:36:41,204
Sound familiar?
570
00:36:43,831 --> 00:36:47,293
That's because we've lived
through this scenario before.
571
00:36:48,127 --> 00:36:51,589
In the 1930s, the Great Plains
were hit by extreme drought.
572
00:36:52,382 --> 00:36:55,468
Farmers had plowed up native grasslands.
573
00:36:55,635 --> 00:37:01,015
When crops failed, unprotected topsoil billowed
into clouds that darkened the sky for days.
574
00:37:03,518 --> 00:37:07,855
Some 400,000 people lost nearly everything
during the dust bowl.
575
00:37:08,189 --> 00:37:12,527
One of America's
worst man-made ecological disasters.
576
00:37:15,530 --> 00:37:19,909
It was the model
for the calamity depicted in Interstellar.
577
00:37:21,661 --> 00:37:24,622
NOLAN: I really wanted to try
and bring the audiences' attention...
578
00:37:24,789 --> 00:37:28,042
...to the idea that this
sort of thing really can happen.
579
00:37:28,209 --> 00:37:32,463
And it struck me
that the imagery that you can find...
580
00:37:32,630 --> 00:37:36,008
...was so much more extraordinary than
anything you see in a science fiction film.
581
00:37:36,175 --> 00:37:39,887
And, indeed, in our portrayal of it,
we had to frankly water it down.
582
00:37:40,638 --> 00:37:43,850
NARRATOR: But we'd never let a dust bowl
happen again, would we?
583
00:37:47,353 --> 00:37:52,442
In recent years, cities in the
American Southwest, especially Texas...
584
00:37:52,608 --> 00:37:55,361
...have been battered by huge dust storms.
585
00:37:55,820 --> 00:38:00,116
They've caused fatal traffic accidents
and damaged infrastructure.
586
00:38:00,283 --> 00:38:04,912
The causes are frighteningly familiar
to UCLA geographer Greg Okin...
587
00:38:05,079 --> 00:38:08,541
...an expert on the dynamics
of wind and dust.
588
00:38:09,250 --> 00:38:10,835
OKIN:
We have wind-erodible soil.
589
00:38:11,002 --> 00:38:13,838
We have agriculture
that's disturbed the native vegetation.
590
00:38:14,005 --> 00:38:17,550
We have bare ground because crops fail.
591
00:38:17,717 --> 00:38:19,427
And we have windy conditions.
592
00:38:19,594 --> 00:38:24,599
So all of the same things that happened
in the dust bowl are happening now.
593
00:38:26,225 --> 00:38:29,979
NARRATOR: Models of climate change
predict higher global temperatures.
594
00:38:30,146 --> 00:38:32,690
That probably means more droughts.
595
00:38:33,399 --> 00:38:36,527
Economic pressures may lead
to increased farming of wildlands.
596
00:38:38,529 --> 00:38:42,742
If crops fail due to drought,
that could mean more dust.
597
00:38:43,117 --> 00:38:44,911
OKIN:
It could happen in China.
598
00:38:45,077 --> 00:38:46,621
It could happen in Africa.
599
00:38:46,787 --> 00:38:51,417
Any of these factors, when they're in place,
could cause what we have called the dust bowl.
600
00:38:52,710 --> 00:38:54,378
NARRATOR:
And to make matters worse...
601
00:38:55,046 --> 00:38:59,342
...dust is much dirtier today
than it was in the 1930s.
602
00:38:59,509 --> 00:39:04,222
OKIN: The dust that is interacting
with clouds of pollution from cities...
603
00:39:04,388 --> 00:39:06,849
...in urban and industrial activities, um...
604
00:39:07,016 --> 00:39:12,063
...that actually does appear
to also be more noxious than regular dust.
605
00:39:12,939 --> 00:39:17,568
NARRATOR: Winds blow dust across oceans
and continents and into our lungs.
606
00:39:17,735 --> 00:39:21,447
Dust, particularly for kids with asthma,
is a really big problem.
607
00:39:21,614 --> 00:39:23,533
There's actually quite good evidence...
608
00:39:23,699 --> 00:39:28,788
...for dust being correlated
with pediatric hospital admissions.
609
00:39:28,955 --> 00:39:31,374
That's where the really clear evidence is.
610
00:39:32,667 --> 00:39:35,920
NARRATOR:
No one predicted the dust bowl of the 1930s.
611
00:39:36,087 --> 00:39:38,172
Today, we should know better.
612
00:39:38,339 --> 00:39:41,968
OKIN: We learned the important lesson
that poorly-planned human activity...
613
00:39:42,134 --> 00:39:47,306
...plus unexpected climate variability
can lead to disaster.
614
00:39:47,473 --> 00:39:49,559
There's a lot to worry about.
615
00:39:51,394 --> 00:39:54,647
NARRATOR: Sadly, we don't have a great
track record taking care of Mother Earth.
616
00:39:56,232 --> 00:40:01,362
But the planet is also threatened
by forces far beyond our control.
617
00:40:05,575 --> 00:40:08,119
February 15th, 2013...
618
00:40:10,329 --> 00:40:14,542
...a meteor shining brighter than the sun
streaks across Siberia.
619
00:40:15,209 --> 00:40:18,170
It's a rock 65 feet in diameter...
620
00:40:18,337 --> 00:40:22,216
...and when it explodes in midair,
it releases more than 20 times the energy...
621
00:40:22,383 --> 00:40:25,094
...of the bomb dropped on Hiroshima.
622
00:40:25,720 --> 00:40:27,388
[SCREAMING]
623
00:40:31,350 --> 00:40:35,646
No one was killed,
but more than a thousand people were injured.
624
00:40:37,898 --> 00:40:40,568
Asteroids have struck Earth before.
625
00:40:40,735 --> 00:40:42,570
Some 65 million years ago...
626
00:40:42,945 --> 00:40:47,742
...a monster 6 miles wide
may have wiped out half the species on Earth.
627
00:40:47,908 --> 00:40:50,077
Remember the dinosaurs?
628
00:40:50,244 --> 00:40:53,456
A similar impact, or worse,
could happen any time...
629
00:40:53,956 --> 00:40:57,335
...and turn our blue marble
into a lifeless rock.
630
00:40:59,545 --> 00:41:00,838
And the bottom line?
631
00:41:01,005 --> 00:41:03,966
Earth cannot sustain us forever.
632
00:41:04,759 --> 00:41:08,971
In a few billion years,
our sun will expand as it begins to die...
633
00:41:10,848 --> 00:41:13,643
...and our planet will be toast.
634
00:41:17,271 --> 00:41:18,481
But there's good news.
635
00:41:18,648 --> 00:41:19,982
Unlike the dinosaurs--
636
00:41:20,149 --> 00:41:22,401
MAN: Flight crew, close and lock your visors.
Time to fly.
637
00:41:22,568 --> 00:41:24,236
NARRATOR:
--we can leave Earth.
638
00:41:24,403 --> 00:41:26,947
MAN:
T-minus-10, nine...
639
00:41:27,114 --> 00:41:28,824
Ignition sequence start.
640
00:41:28,991 --> 00:41:33,954
Six, five, four, three, two, one.
641
00:41:34,830 --> 00:41:36,290
Zero.
642
00:41:40,336 --> 00:41:44,215
Zero and liftoff of space shuttle Atlantis.
643
00:41:44,382 --> 00:41:47,718
NARRATOR: Today, nearly 600 people
have traveled to space.
644
00:41:49,553 --> 00:41:54,350
During the shuttle era,
Marsha Ivins made the trip five times.
645
00:41:54,517 --> 00:42:00,314
In order to record all of this, um, we have
created this, uh, wiring nightmare here.
646
00:42:00,481 --> 00:42:05,111
NARRATOR: At Kennedy Space Center Visitor
Complex, she checks in on an old friend.
647
00:42:06,904 --> 00:42:11,826
IVINS: I look at Atlantis hanging here,
it's a surreal kind of experience to think...
648
00:42:12,535 --> 00:42:14,495
...I flew that into space.
649
00:42:14,662 --> 00:42:17,123
It's still something
that I have a hard time believing.
650
00:42:17,289 --> 00:42:18,624
-Hi.
-My name is Tanya.
651
00:42:18,791 --> 00:42:20,000
PHOTOGRAPHER:
One, two, three.
652
00:42:20,167 --> 00:42:24,004
And it makes me feel good
that people still have a wonder...
653
00:42:24,171 --> 00:42:27,800
...and an amazement and a pure joy...
654
00:42:27,967 --> 00:42:31,971
...for the fact that we did fly this vehicle
into space.
655
00:42:32,513 --> 00:42:37,351
NARRATOR: For Marsha,
each mission was as breathtaking as her first.
656
00:42:37,518 --> 00:42:39,603
IVINS:
I looked up overhead...
657
00:42:39,770 --> 00:42:45,985
...and here was this black sky
and this blue Earth.
658
00:42:46,152 --> 00:42:50,656
All hits you at that point,
"I am not on the planet anymore."
659
00:42:51,031 --> 00:42:54,910
And every astronaut who has flown
has come back and said the same thing.
660
00:42:55,077 --> 00:42:56,829
As you circle the Earth...
661
00:42:56,996 --> 00:43:02,710
...you do not see natural borders
and boundaries that separate the countries.
662
00:43:02,877 --> 00:43:08,090
And all of the wars and the angst
and the strife that tear this planet apart...
663
00:43:08,257 --> 00:43:11,135
...seem so insignificant from that view.
664
00:43:12,428 --> 00:43:13,637
NOLAN:
To me...
665
00:43:14,180 --> 00:43:19,852
...space travel, space exploration
has always represented the ultimate frontier.
666
00:43:20,019 --> 00:43:23,898
It's of the absolute extremities
of what human experience is...
667
00:43:24,064 --> 00:43:28,235
...and it's all about trying to, in some way,
define our place in the universe.
668
00:43:28,402 --> 00:43:32,072
MAN: Forty seconds away
from the Apollo 11 liftoff.
669
00:43:32,239 --> 00:43:33,908
JONATHAN:
I remember growing up as a kid...
670
00:43:34,074 --> 00:43:37,953
...and we were both fascinated
by this impulse to flight.
671
00:43:38,120 --> 00:43:44,293
This impulse to build unimaginable machines
and use them to blast off into space.
672
00:43:45,294 --> 00:43:51,091
MAN: Having fired the imagination of
a generation, pulls into port for the last time.
673
00:43:51,258 --> 00:43:54,011
NARRATOR:
The space shuttles were retired in 2011...
674
00:43:54,178 --> 00:43:57,515
...after traveling more than
a half billion miles.
675
00:43:59,934 --> 00:44:03,145
Space exploration demands
enormous resources.
676
00:44:03,312 --> 00:44:06,607
The kind that government agencies
like NASA can marshal.
677
00:44:07,858 --> 00:44:10,653
Recently, some new players entered the fray.
678
00:44:11,695 --> 00:44:14,865
MUSK: I do think we're at the dawn
of a new space era...
679
00:44:15,032 --> 00:44:17,618
...and it's one where commercial companies
play a stronger role.
680
00:44:17,785 --> 00:44:19,328
NASA's not out of the picture.
681
00:44:19,495 --> 00:44:25,209
They're very much in the picture,
but it's not all a NASA-designed system.
682
00:44:26,043 --> 00:44:31,090
NARRATOR: In 2002, Elon Musk started
his own rocket company.
683
00:44:31,257 --> 00:44:34,301
A decade later, under contract to NASA...
684
00:44:34,468 --> 00:44:38,514
...Spacex became the first private company
in history to carry supplies...
685
00:44:38,681 --> 00:44:41,141
...to and from
the International Space Station.
686
00:44:44,979 --> 00:44:48,691
Now Spacex is tackling
an even greater challenge.
687
00:44:48,858 --> 00:44:53,404
MUSK: I started Spacex with the idea
of trying to revolutionize space transport.
688
00:44:53,571 --> 00:44:57,992
And critical to that
is full and rapid reusability of the rocket.
689
00:44:59,326 --> 00:45:02,705
The big issue with rocketry today
is you get one use out of the rocket...
690
00:45:02,872 --> 00:45:07,501
...and then it smashes down into the ocean
or into the plains of Siberia, um...
691
00:45:07,668 --> 00:45:09,378
...and you can't use it again.
692
00:45:10,963 --> 00:45:13,799
If you can, in fact, land the rocket safely...
693
00:45:13,966 --> 00:45:16,594
...and then reuse it
with a minimal amount of effort...
694
00:45:16,760 --> 00:45:22,308
...then you can dramatically
reduce the cost of space transport.
695
00:45:22,474 --> 00:45:27,688
NARRATOR: Spacex is currently developing
a fully and rapidly reusable launch system.
696
00:45:27,855 --> 00:45:30,649
And that will take Elon closer
to a more ambitious goal:
697
00:45:31,609 --> 00:45:36,405
To help send crews
to establish a colony on Mars.
698
00:45:37,114 --> 00:45:39,825
Not a mission for the fainthearted.
699
00:45:40,492 --> 00:45:42,077
MUSK:
Anyone who wants to go to Mars...
700
00:45:42,244 --> 00:45:47,875
...their desire for adventure would have to
overcome their desire for comfort and safety.
701
00:45:48,876 --> 00:45:53,339
NARRATOR: The colony on Mars
could be the next giant leap for humankind.
702
00:45:53,505 --> 00:45:56,634
NOLAN: It's such a fundamental idea
when you think about it.
703
00:45:56,800 --> 00:46:00,471
It's just a decision that has to be made
in terms of how you view the--
704
00:46:00,638 --> 00:46:02,890
The human race's place in the universe.
705
00:46:03,057 --> 00:46:09,104
We either stay here on Earth or we leave
and we journey through the galaxy.
706
00:46:12,399 --> 00:46:15,194
NARRATOR: To create the look
of the space technology in Interstellar...
707
00:46:15,361 --> 00:46:18,781
...Christopher Nolan
took a clear design approach.
708
00:46:18,948 --> 00:46:22,868
NOLAN: We didn't wanna have anything
that felt purely decorative.
709
00:46:23,035 --> 00:46:26,789
We wanted to approach it
from a more functional point of view...
710
00:46:26,956 --> 00:46:28,916
...just be as convincing as possible...
711
00:46:29,083 --> 00:46:31,710
...looking at the NASA technology
that exists today...
712
00:46:31,877 --> 00:46:34,922
...the International Space Station,
these kind of things as our influences.
713
00:46:36,215 --> 00:46:40,260
NARRATOR: There's no telling how space
technology will evolve in the years to come.
714
00:46:41,220 --> 00:46:46,433
We may be decades away or longer
from establishing a colony on Mars...
715
00:46:46,934 --> 00:46:50,187
...or a permanent habitat
in orbit around the Earth.
716
00:46:50,354 --> 00:46:53,565
But people around the world
are dreaming of that next step.
717
00:46:56,235 --> 00:46:58,904
At a recent space conference...
718
00:46:59,071 --> 00:47:01,073
...NASA and the National Space Society...
719
00:47:01,407 --> 00:47:05,369
...handed out awards
to dozens of forward-looking designs.
720
00:47:07,788 --> 00:47:11,000
A self-sustaining settlement
for 20,000 people.
721
00:47:12,543 --> 00:47:16,463
A moon base that mines minerals
from lunar soil.
722
00:47:17,006 --> 00:47:20,384
A fleet of robots that clean up space junk.
723
00:47:20,551 --> 00:47:23,012
But, of course, this is hard
because we're burning fuel...
724
00:47:23,178 --> 00:47:26,557
NARRATOR: There's not a single PhD
among the prize-winning designers.
725
00:47:26,724 --> 00:47:28,892
[SINGING IN SPANISH]
726
00:47:30,144 --> 00:47:33,480
NARRATOR: These are middle and high school
students from around the world.
727
00:47:33,647 --> 00:47:39,278
What first inspired me was the sky,
the stars, the moon, the planets.
728
00:47:39,445 --> 00:47:44,533
Thinking about going to space
is really exhilarating.
729
00:47:44,700 --> 00:47:48,829
I've always wanted to know, like, what's next?
And for me, space is next.
730
00:47:48,996 --> 00:47:51,248
What we can do is beyond our imagination.
731
00:47:51,623 --> 00:47:57,713
For the survival of the human race,
really, the only option is to go into space.
732
00:47:57,880 --> 00:48:01,592
It should be something that--
A first step we should take as a world.
733
00:48:01,759 --> 00:48:05,137
NARRATOR: One of these kids
may stand on Mars someday...
734
00:48:05,304 --> 00:48:07,514
...or make a breakthrough
in propulsion systems...
735
00:48:08,015 --> 00:48:10,559
...or start a revolution in astrophysics.
736
00:48:11,935 --> 00:48:16,023
To inspire their kind of enthusiasm
is the hope of the Interstellar team.
737
00:48:16,565 --> 00:48:19,026
THOMAS:
I would love for kids to watch Interstellar...
738
00:48:19,193 --> 00:48:23,322
...and get excited about possibilities
of space travel and exploration.
739
00:48:23,655 --> 00:48:28,952
I would hope that this film
introduces many people to science...
740
00:48:29,119 --> 00:48:32,873
...who might not have gotten curious
about this kind of science in any other way.
741
00:48:33,040 --> 00:48:36,710
I think it would be really thrilling
if people got some sense from this film...
742
00:48:36,877 --> 00:48:39,505
...that, uh, these ideas
are worth thinking about.
743
00:48:42,216 --> 00:48:44,968
NARRATOR: The interplay between science
and science fiction...
744
00:48:45,135 --> 00:48:47,763
...springs from a
deep-seated creative drive.
745
00:48:51,266 --> 00:48:52,601
To make sense of the unknown.
746
00:49:01,110 --> 00:49:02,694
To engineer new worlds.
747
00:49:07,783 --> 00:49:09,535
To dream up a better future.
748
00:49:10,786 --> 00:49:14,206
We'll find answers where we always have:
749
00:49:14,873 --> 00:49:17,459
Just beyond the next horizon.
74420
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