All language subtitles for through.the.wormhole.s01e02.the.riddle.of.black.holes.hdtv.xvid-reb

There are monsters out in the cosmos
that can swallow entire stars

that can destroy space itself.

Black holes.

For decades, they remained
completely hidden.

But now,

scientists are venturing
into their uncharted territory.

They've discovered
that black holes

don't just rule the realm
of stars and galaxies.

They impact all of us
here on Earth,

because black holes
just might be the key

to understanding
the true nature of reality.

Space, time, life itself.

The secrets of the cosmos
lie through the wormhole.

♪ Through the Wormhole 1x02 ♪
The Riddle of Black Holes
Original air date on June 16, 2010

-- sync, corrected by elderman --
-- for www.Addic7ed.Com --

Take planet Earth

and squeeze it
down to the size of a marble.

You'll create an object so dense

that not even light, traveling
at 186,000 miles per second,

can escape its extraordinary
gravitational pull.

Its name --

a black hole.

Astropsicists think
that black holes might form

when giant stars run out of fuel

and collapse
under their own weight.

We're not really sure.
Why?

Because black holes are places

where the accepted laws
of physics break down.

A few bold thinkers
are now making giant strides

towards understanding what
goes on inside black holes.

And the new laws of physics
that emerge

have an astonishing
implication --

you, me,
and the world we live in

may be nothing more
than an illusion.

In my hometown in Mississippi,
there was a well.

It fascinated me to gaze
into its murky depths

to try and see
what lay at the bottom.

I would sit there,
throwing pebbles into it

and trying desperately to hear
a faint splash of water.

But all I got was silence.

One day, I took
a dime-store toy soldier,

made a parachute for it
out of an old handkerchief,

and watched it float down.

I wondered what would happen
to him when he hit the bottom

or if he would
just keep on falling forever

into that
impenetrable blackness.

Today, theoretical physicists
are drawn to black holes

like I was to that old well,

trying to understand
how they really work

and what they can tell us
about the universe.

It's one of those things that
sounds like science fiction,

only it's better
because, you know, it's real.

A black hole is
the window into a world

that we don't have
the concept --

we don't even have
the mental architecture yet

to be able to envision properly.

You're in this strange world
of strong gravity,

where there are
no straight lines anymore.

You can't even see it.

That is disturbing and exciting
at the same time.

The notion of a black hole

is a natural extension
of the laws of gravity.

The closer you are
to a massive object,

the more the pull of its gravity

slows down anything trying
to escape from it.

The surface of the Earth

is 4,000 miles away
from its center.

So the force of gravity up here
is not very strong.

Even a kid can resist it
for a second or two.

But if you could
squeeze the Earth down

so that all of its mass
is really close to the center,

the force of gravity
would grow incredibly strong.

Nothing could move fast enough
to leave its surface.

Not just a jumping boy --

even the beams of light
speeding out from his shoes

would be trapped.

So, if you're trying to imagine

creating something so dense
that not even light can escape,

you're trying to get
a system so compact

that the speed that it takes
to escape from that object

is greater
than the speed of light.

Now, the speed of light
is 186,000 miles per second,

so that's going really fast.

Gravity's quite weak. I think
it's surprising, you know.

The whole Earth is pulling
on a rocket ship,

and all it has to do is go
7 miles per second

to escape from the Earth.

And to get all the way
to a black hole,

you'd have to crunch down
the entire sun

to be less
than a few kilometers across.

Now it would take something

traveling greater than the speed
of light to escape,

so nothing can escape,
and the whole object goes dark.

Christian Ott,
an astrophysicist

at the California institute
of Technology,

has been trying to understand

how such strange entities
as black holes

might really form in the cosmos.

He studies what goes on

when giant stars run out of fuel
and start to shrink,

a process comparable
to the collapse

of an exhausted marathon runner.

So, sometimes you can compare
a star at the prime of its life

to a runner who's
just starting out real fresh,

consuming oxygen aerobically.

And it's the same with stars.

They burn hydrogen
into helium slowly,

and they're getting
a lot of energy

out of every single hydrogen
nucleus they burn.

After they're done fusing
hydrogen into helium,

they go on to more and more
heavy elements,

and that fuel
goes fast and fast.

So, at the end,
they end up with iron,

and that's when their --
when their fuel is over,

their fuel is out.

And it's basically
like a marathon runner

hitting a wall in a marathon.

But, unlike a runner

who can restore his energy
with food and drink,

a dying star has no way
to come back from the brink.

Ugh.

There's no more heat generation,

no more energy generation
happening at its core.

So, gravity keeps on pulling in,

and when there's nothing

producing pressure
to sustain it,

it will just collapse.

You get a shock wave,
and the shock wave moves out.

And it actually blows up
the entire star,

and that's the phenomenon
we call supernova.

The death throes
of giant stars

are the most dramatic events
astronomers have ever witnessed.

Chinese stargazers
saw one explode in 1054.

It was so bright, they could
even watch it by day.

Another two blew up
around 400 years ago.

These colossal explosions

leave debris fields
of gas and dust

hundreds of light-years across,

still visible
and still expanding today.

But what interests
black-hole researchers

is not the explosion.

It's what happens at the very
center of the dying star.

Modern astronomers

have never witnessed a star
in our own galaxy explode.

But theoretical physics predicts
that if a star is large enough,

its collapsing core

should shrink down
to form a black hole.

So, imagine the balloon
is a star.

And the star stays alive
by burning thermonuclear fuel,

and as it does so,

you get heavier elements
like the sponge

and all that energy released,

like the energy
released in a bomb.

So, as a star runs out of fuel,
it begins to cool.

And as it cools, it's no longer
supported by all that pressure,

and so it starts to collapse
under its own weight.

And it will continue to collapse
until it gets so small

that now you're running up
against the essure

of crushing the matter together.

And at this stage,

it's a little bigger
than the size of the Earth,

and it's supported by pushing
all of the electrons

in the atoms
closer and closer together.

Now, if it's more massive
than a couple of times the
mass of the sun,

it will start
to collapse even further.

And there is no form of pressure
that can resist this collapse.

And it will continue
to collapse down

until it forms a black hole.

But do such strange
crushed corpses of stars

really exist out in the cosmos?

Could they be lurking
at the center

of some of those clouds
of gas and dust

thrown off in a supernova?

Christian Ott and his
theoretical-astrophysicist group

at caltech

are trying to discover
whether exploding stars

really do form black holes.

Well, I just generally --
you know,

I'm really excited about stars
that blow up, actually.

First of all,
to get a black hole,

you need low,
specific angular momentum.

To have a critically spinning
black hole,

you need a lot
of angular momentum, so...

There are two ways to find out

whether black holes really form
when stars blow up.

One is to wait for a supernova
to go off in our galaxy

and use every tool of modern
astronomy to pick it apart.

A galactic supernova would
provide us so much information,

we wouldn't sleep for weeks.

But, unfortunately, it happens

only maybe once or twice
per century.

So, Christian and his team are
trying a different approach --

blowing up stars
inside powerful supercomputers.

This is no easy task.

In fact,
no one has pulled it off.

But Christian is on his way
to being the first.

So, simulating
supernovae stellar collapse

and black-hole formation

is so hard because it brings
together a lot of physics.

It's general relativity
for gravity.

It's fluid dynamics for the gas
that collapses.

It's particle physics.

Doing the simulations,

it's like trying to do
a really good weather forecast.

So far, Christian has failed

to make a virtual star explode

in a way that looks
like a real supernova.

But after years of refining
the physics and the math,

he now thinks
he may be the first

to fully understand
how a black hole is born.

Man, that is
an event horizon right there,

and this black hole
in the center.

Wow, that's the first time
that we do see this.

What's surprising is

that the most promising
simulations

don't actually explode.

They simply collapse.

It's not a bang but a whimper.

Its name --
not supernova, but unnova.

It's basically
just everything

eventually sinks
into a black hole,

and the star slowly but surely
just disappears.

It could be true
that most stars,

or a large fraction of stars,
just disappear.

We don't have any data on that.
We have never seen an unnova.

If Christian is right
and black holes form silently,

then these cosmic cannibals
could be hidden

in plain sight all around us,

and we might never know it.

Finding black holes is
terribly, terribly difficult.

Even if it wasn't black
and would be radiating energy,

it would still be only,
let's say, 20 miles across.

And even, you know,
at 10 light-years away,

it would be impossible to find

even with the best telescopes
we have.

But if black holes
are almost completely elusive,

no one told this man.

He's spent the past 30 years
hunting one, a giant one,

right at the heart
of our own Milky Way galaxy.

And his discovery
will overturn all our ideas

about how the universe
really works.

In 1931,

a bell telephone researcher,
Karl Jansky,

was testing a new system
for sending radio messages

across the Atlantic to Europe.

He was plagued
by background noise.

After two years of careful work,

Jansky stripped out
most of the interference.

But one strange signal
never went away.

It was loudest
whenever his antenna was pointed

at the constellation Sagittarius

at the very heart
of the Milky Way.

It was a signal unlike anything
a star would make.

Astronomers began to wonder
whether it might come

from an object theorists had
predicted but never detected --

a black hole.

But there was no way
to find out.

The center of our galaxy
is hidden from view

by a thick veil of dust.

Then, 25 years ago,

a German astronomer,
Reinhard Genzel,

found a way
to see through the fog.

The problem is we are sitting
in the Milky Way,

and the galactic center
is sort of just along the way

through the entire plane

of this big spiral galaxy
we're sitting in.

And there's all this gunk,
this dust and this gas,

between us
and the galactic center,

so we can't see it
in the visible.

But at longer wavelengths,
this dust is not as efficient.

Infrared light,
with its longer wavelength,

is perfect
for penetrating the veil.

But it's terrible

at getting through the water
vapor in Earth's atmosphere.

So Reinhard Genzel headed

for the highest and driest place
on Earth --

the Atacama Desert of Chile.

Beginning in 1992,

he and his team
at the Max Planck Institute

began what would become
an enduring campaign

to find out
exactly what was causing

the strange noise at the center
of the Milky Way.

In fact, we found in the center
of the Milky Way

a very dense collection
of stars.

That's the very center
of the Milky Way,

around which, you know,
everything turns.

And then came
the first suspicions --

maybe there is something there.

Reinhard had a hunch
that a black hole

could be acting
as a colossal center of gravity,

causing dozens of stars
to whirl around it.

So he settled in
for the long haul.

Each year, he took
another set of pictures,

plotting the movement
of that cluster of stars

at our galaxy's heart.

He gathered a large team

to help him handle
the immense amounts of data

and used a new technique
called adaptive optics

to make the images
of these distant stars sharper.

So, if you look at what the
galactic center would look like

in a normal telescope,
let's say,

you would get images
which look like that.

The effect
of this adaptive optics

you can see
on the right-hand side.

It's just amazing how beautiful
that image gets.

It's really the same scene.

You can recognize those two
stars here on the left-hand side

in the blurred image there --

these two stars
on the right-hand side.

As the years went by,
a striking pattern emerged.

Stars were moving --
moving really fast.

This was something
that no astronomer

had ever seen before --

a dozen, then 20, then 30 stars

all swirling at breakneck speed
around a central object

that was completely dark
and tremendously dense.

Could this be the first proof
that black holes existed?

And if so,
was there really one here

right in the center
of our own galaxy?

What do you do
in order to see something

or prove the existence
of something

which you can't really see,
right?

The black hole, you would think,
is something,

well, by definition,
light can't escape from.

But you have gravity.
Think of the solar system.

Okay, you have the sun
in the center,

and then you have the planets.

The outer planets move
very slowly around the sun.

And the closer you come to the
sun, the faster the planets go.

So, suppose in your mind
you switch off the sun.

You would have to conclude
that there is a central object

with one solar mass,
around which the planets orbit.

See, that's what we're doing.

So, these are the stars
that are shown.

Here at the very center here
is the radio source,

which we suspect is the location
of the black hole.

This is our best star,

which we have followed for
15 years to trace a full orbit.

This star,
known only by the name S2,

was moving at a phenomenal rate.

At its closest approach
to the dark central object,

Reinhard and his team
clocked it moving

at 11 million miles per hour.

What we learned
from this is that, indeed,

there's only one central mass
right there

at the position
of the radio source,

and that has
four million solar masses.

There cannot really be
any believable configuration

which we know of
other than the black hole.

Reinhard Genzel had made

the first definitive discovery
of a black hole.

But more than that,
his team had found an object

that must have swallowed
millions of stars

over its lifetime.

Astronomers call it
a supermassive black hole.

But despite the enormity
of this discovery,

it would be just the first

of many increasingly bizarre
and disturbing findings.

The next was to figure out

what goes on
inside a black hole.

What happens to stars,
planets, even people

if they get too close
to this cosmic sinkhole?

No telescope can ever see
inside black holes.

To understand
how they twist reality,

we have to stop looking
and learn how to listen.

Lurking at the center
of our galaxy

is an object
that's completely invisible

but weighs as much
as four million stars.

Astronomers now believe
almost every galaxy has

a supermassive black hole
at its core.

So, what are they?

Science fiction sees black holes
as cosmic time machines

or portals
to a parallel universe.

But real scientists are finding

that truth is stranger
than sci fi.

You're about to enter a world

where the very big
and the very small

are indistinguishable,

where reality and illusion
are one and the same.

Astronomer Julie Comerford

has been studying the centers
of dozens of distant galaxies,

trying to find signs
of black holes,

hoping to learn more about
these mind-bending objects.

It turns out that in all
or nearly all galaxies,

wherever we look,

they have a central supermassive
black hole at their heart.

Supermassive ones are the ones
that have masses

of anywhere from a million
to a billion times

the mass of the sun.

You can see
a supermassive black hole

when gas is falling onto it.

And sort of right
before the gas falls into it,

it gets heated up
and emits a lot of energy

and can appear really bright.

But when Julie
investigates the glowing gas

surrounding
these giant black holes,

she finds something
totally unexpected.

There's a cosmic dance going on

on a scale
that's almost unimaginable.

You saw two peaks in the light
instead of just one.

You'd expect one
from one black hole

that's just sitting
at rest in its galaxy,

but we saw two peaks
with different velocities.

And that immediately hit us,

as this has got to be
something interesting.

Julie began thinking

about what would happen
when two galaxies collide.

And if both had black holes
at their centers,

what would happen
to those massive objects?

So, when two galaxies collide,

the black holes
at their center --

instead of crashing in head-on,

they begin this swirl, or dance.

And the way that we can detect
these waltzing black holes

is by looking at the light
that's emitted from them.

So, for the black hole
that's moving towards us,

we detect light
that is at smaller wavelengths,

scrunched up together,
so we see bluer light.

And for the black hole
that's moving away from us,

we see stretched-out,
longer-wavelength light

that appears redder.

So it's this redder
and bluer light

that is a telltale signature
of a black-hole waltz.

Every time we see it,

we high-five
in the observation room,

and you just can't get over it.

As Julie scans the universe,

she finds
the same remarkable dance

happening time and time again.

In galaxy after galaxy,

black holes are paired up

and dancing
the cosmic night away.

So, we identified 90 galaxies

from when the universe
was half its present age,

and we found that fully 32
of them, or about a third,

had black holes that exhibited
this blue-and-red signature.

So that was really surprising

that such a high fraction
of the black holes

were not stationary at
the center of the galaxy at all,

that they were undergoing this
waltz with another black hole.

Scientists
like Janna Levin believe

the discovery
of waltzing black holes

opens up a whole new way
to learn what's inside them,

because their dance
might not only be visible.

It could also be audible.

The scientific visionary
Albert Einstein

saw space and time
as a flexible material

that could be distorted
by gravity.

A black hole is merely a very
deep well in this material.

When two black holes
come close to one another,

these two orbiting wells

stir up space-time
and send out ripples

that can travel
clear across the universe.

And these waves will move out
through the universe,

traveling at the speed of light.

So we can hope to not see
black holes with light

but maybe, in some sense,
hear them

if we can pick up the wobbling

of the fabric
of space-time itself.

For the past several years,

Janna and her colleagues
have been trying to predict

the sounds black holes make
as they spin around one another.

The calculations are not
for the faint of heart.

Modeling what happens
when two giant objects

create a storm
in the sea of space-time

takes some serious math
and months of supercomputing.

This is the orbit
of a small black hole

around a bigger black hole,

and it's literally making
a knocking sound on the drum,

where the drum
is space-time itself.

Well, it really sounds like --
sounds like a knocking.

It starts to get a higher
frequency and happen faster,

until it falls
into the big black hole

and goes down the throat.

And then the two
will ring out together

and form one black hole
at the end of the day.

And then it just sort of,
you know, "brr," chirps up.

Because black holes

stir up the space and time
around them so much,

the orbit of one black hole
around another

looks nothing like the orbit
of Earth around the sun.

An orbit can come in
around a black hole

and do an entire circle
as it loops around

before it moves out again.

So instead of getting an oval,

you get a three-leaf clover
that processes around.

This cloverleaf pattern

keeps coming
out of the simulations.

Janna was shocked
because this picture

of how two of the heaviest
objects in the universe

move around one another

bears an uncanny resemblance
to the way

two of the lightest objects
move around one another --

the tiny protons and electrons
inside an atom.

We can build
a kind of classical atom

out of a big black hole,
like a nucleus,

and a light black hole,
which acts like an electron.

And together, they form
a real atom, in a sense.

How could an object
that weighs so much

behave like a subatomic particle
that weighs so little?

When we talk about ordinary
objects, or people even,

they are never exactly the same.

I mean, you could try
to clone me,

and still
the different copies of me

would not be exactly the same.

In that sense,
people and ordinary objects

are not like
fundamental particles.

They're distinguishable.

But the black hole is
quite different from that.

Black holes are
like fundamental particles,

and that's very surprising

because they're huge,
macroscopic objects.

Right now, this idea is
only a tantalizing hunch.

But in just five years,
super-sensitive detectors

should be able to pick up
the ripples in space created

by two massive black holes
spinning around one another.

And they'll tell us

whether they really do behave
like tiny atoms.

But this connection between
the very big and the very small

has already sparked a war

between two of the greatest
living physicists.

One of them -- Stephen Hawking.

The other began life
as a plumber in the South Bronx

and is now using black holes
to develop

the most revolutionary idea in
physics since Albert Einstein --

an idea that literally turns
reality inside out.

Black holes

are the most massive objects
in the universe.

Some weigh as much as a billion
times more than our sun.

But no one really knows
how big they are.

All that mass could fit into
a space smaller than an atom.

And that's where physics
runs off the rails.

Albert Einstein's
theory of relativity

explains gravity beautifully,

but it only works
for very large objects,

not for tiny building blocks
of matter likeke atoms.

We understand
so much since Einstein,

but somehow gravity stands apart
from our understanding

of everything else in nature.

There's matter on one side,

and there's gravity
on the other side.

And there's this great ambition
to put those two together,

to understand them
as one law of physics.

The first step in joining

the physics of the very large
and the very small

came in 1974 from the mind
of Stephen Hawking.

The theory of the very small,
quantum mechanics,

predicts that empty space
should be sizzling

with particles
and antiparticles,

popping into existence in pairs

and then annihilating
one another an instant later.

These particles exist
for such a short time,

they're not considered
part of reality.

Physicists call them
virtual particles.

But Hawking realized

there was one special place
in the universe

where these particles
could become real.

Around a black hole,

there is an invisible line
in space

called the event horizon.

Outside that line,

the hole's gravity is
just too weak to trap light.

Inside it, nothing can escape
its pull.

If a pair
of virtual particles fmed

just outside the event horizon,

then one of the pair

might travel across
that point of no return

before being able to recombine,

falling into the black hole
and leaving its partner

to escape as real radiation --
Hawking radiation.

If Hawking is right,

black holes should not
actually be black.

They should shine
ever so faintly.

No one has ever detected
Hawking radiation

from the rim of a black hole.

In fact, it's so faint,
and black holes are so far away,

that it will
probably never be possible.

But Jeff Steinhauer
thinks he's found a way

to test Hawking's theory

and send shock waves
through the world of physics.

He's the only person
on the planet

who has seen a black hole
from up close.

In fact, he's learned
how to create one.

My black hole
is in no way dangerous.

It's a sonic black hole that can
only absorb sound waves.

It's only made of 100,000 atoms,
which is very little matter.

And I'm sure
that my neighbors would love

that I would put a sonic
black hole around my apartment,

but it's not gonna happen.

When he's not jamming
in the basement

of the physics department
at the Technion in Israel,

he's upstairs in his lab.

Jeff Steinhauer's recipe
for making a sonic black hole

begins with a tiny sample
of rubidium atoms

chilled down
to minus-459 degrees fahrenheit.

While I was working
with these very cold atoms,

I stumbled across a phenomenon.

When the atoms are
actually flowing

faster than the speed of sound,

then, if there are sound waves

trying to travel
against the flow,

they can't go forward.

And this is analogous
to a real black hole,

where light waves cannot escape
due to the strong gravitation.

Even though this black hole

traps only sound, not light,

the same laws
of quantum mechanics apply to it

as they do
to its cosmic cousins.

If Hawking's theory
about black holes is correct,

Jeff should be able to detect
tiny sound waves escaping.

There should be
pairs of sound waves,

one on the right side
and one on the left side.

Due to the quantum physics,
they will suddenly be created.

This is
the elusive Hawking radiation.

Jeff has not detected
this elusive radiation yet.

But he believes he should
within a year

as he refines his experiment.

No one will await that news

more keenly
than Leonard Susskind.

He has spent much
of the last 30 years

thinking about Hawking radiation

and being deeply troubled
by what it means.

Today, he is one of the world's
leading theoretical physicists.

But that's not
the way he started.

When I was 16 years old,
I was a plumber.

Fixing toilets and sewers
and so forth

in tenement buildings
in the South Bronx

was not what I wanted to be
doing for the rest of my life.

Whenever I make analogies
about physics,

it always seems that they have
something to do with plumbing.

The analogy that I've used
over and over about black holes

is water going down a drain.

The invention of string theory,

which has a lot to do
with tubes --

some people even say

this must've been
Susskind the plumber.

Leonard Susskind's
fascination with black holes

began 30 years ago

when he listened to a talk
by Stephen Hawking --

a talk that triggered
a violent reaction.

I first heard Stephen Hawking
give a lecture

up in San Francisco,

in which he made
this extraordinary claim

that black holes seem to violate

the very, very fundamental
principle of physics

called conservation
of information.

Seven years
after his groundbreaking work

on black-hole radiation,

Hawking had taken the idea
to its logical conclusion.

For every ounce of material

a black hole absorbed
into its core,

it would radiate away
an equivalent amount of energy

from its event horizon.

But since there is
no physical link

between the center of a black
hole and its event horizon,

the two processes
could not share any information.

Now, this was a disaster
from the point of view

of the basic principles
of physics.

The basic principles
of physics say

that you can't lose information.

Let me give you an exale.

Here's a sink of water.

Imagine sending in a message
into that sink of water

in the form of morse code
by dropping in this red ink.

Drip, drip, drip, drop, drip.

You see the red ink
swirling around,

but if you wait a few hours,
what will happen

is that red ink will get
diffused throughout the water.

You might say,
well, my goodness,

the information
is clearly lost --

nobody can reconstruct it now.

But down at the very core
of physical principles,

no, that information is there.

If you could watch
every single molecule,

you could reconstruct
that message.

It may be much too hard
for human beings

to be able to reconstruct
and to follow all those motions,

but physics says it's there.

But Stephen Hawking claimed

there are special places
in the universe

where that law can be broken.

What happens
when the information

goes down the black hole?

The answer,
according to Stephen,

was it goes down the drain

and disappears completely
from our universe.

This was a fundamental violation

of the most sacred principle
of physics.

And I was personally,
truly shocked.

If what Hawking claimed
was right,

it would mean
most of modern physics

had to be seriously flawed.

Black holes would spend
their lives eating stars

and leave no record
of what they'd done.

Nothing else in the universe
does this.

The fiery blast
of a nuclear bomb

might vaporize
everything in sight,

but all that information
is still in this universe,

no matter how scrambled.

Black holes,
according to Hawking,

don't scramble information.

They completely destroy it.

That was 1981,

and from that time forward,
I was hooked.

I could not let go
of the question of black holes.

This squabble soon
grows beyond these two men

and engulfs all of physics.

At stake is more than just
bragging rights for the winner.

It turns out to affect the very
way we perceive the universe.

There may be
100 million black holes

scattered across the Milky Way.

Anything that strays too close

to these dark remnants
of burned-out stars

will be pulled in by an intense
gravitational field.

But what actually happens

to the stuff
that falls into a black hole?

Is it simply wiped out
of existence,

or do black holes remember?

These are the battle lines

of the black-hole war --

a battle with repercussions

that the men who started it

could never have imagined.

It's a war
between two giant minds.

On one side, the famous
physicist Stephen Hawking,

on the other, Leonard Susskind,

one of the creators
of string theory,

a notoriously difficult branch
of physics.

Stephen Hawking argues

black holes destroy what they
swallow without a trace.

Leonard Susskind
passionately disagrees.

But for 10 years,

he struggled
to find anything wrong

with Hawking's concept

of how black holes radiate away
the matter they swallow.

It was thought to be
inconceivable

that somehow the things
which fell into the black hole

could have anything to do
with the Hawking radiation,

which was coming out
from very, very far,

from where the particles
fell in.

Then he began looking
at the problem in a new way.

Call it
the dead-and-alive paradox.

It's a cosmic thought experiment

starring an astronaut
named Alice,

her friend Bob,
and a black hole.

Bob is orbiting
the black hole in a spaceship,

and Alice decides to jump
into the black hole.

What does Bob see,
and what does Alice see?

Well, Bob sees Alice falling
toward the black hole,

getting closer and closer to
the horizon, but slowing down.

Because the gravity
of the black hole

severely distorts space and time
near the event horizon,

Einstein's theory of relativity
predicts

that Bob will see Alice
moving slower and slower,

until she eventually stops.

So, from Bob's point of view,

Alice simply becomes
completely immobile

with a big smile on her face.

And that's the end of the story.

It takes forever for Alice
to fall through the black hole.

On other hand,

Alice has a completely different
description of what happens.

She just falls completely
cleanly through the horizon,

feeling no pain, no bump.

It's only when she approaches
the interior

when she starts
to feel uncomfortable.

And at that point, she starts
to get more and more distorted,

and I don't want to go
into detail what happens to her.

It's not pretty.

These two descriptions
of the same events

appear to be at odds.

In one, Alice is stuck
at the event horizon.

In the other,
she sails right through.

In one version, she dies.

In the other,
she's frozen in time but alive.

But then Leonard Susskind
suddenly realized

how to resolve this paradox
and win the black-hole war.

Well, I began to think
that some of the ideas

that we had developed
for string theory

could help resolve this problem,
this paradox.

One way of thinking
about string theory

is that elementary particles are
simply more than meets the eye.

You see this propeller here?

This propeller -- when it's
spinning very, very rapidly,

all you see is the central hub.

It looks like no more
than a simple particle.

But if you had
a really high-speed camera

that could catch it
as it was spinning,

you would discover that there's
more to it than you realized.

There's the blades.

And the blades would make it
look bigger.

In string theory,

an elementary particle has
vibrations on top of vibrations.

It's as though this propeller

had, on the ends of its blades,
more propellers.

And those propellers
had propellers

on the ends of their blades,
out to infinity,

each propeller going faster
than the previous one.

As you would catch it with a
higher- and higher-speed camera,

you would see more and more
structure come into focus,

and the particle
would seem to grow.

It would grow endlessly

until it filled up
the whole universe.

Leonard realized

that a black hole is like
an ultra-high-speed camera.

It appears to slow objects down

as they approach
the event horizon.

Time for another
thought experiment.

The black hole,
Bob, and Alice are back,

but this time,
Alice has an airplane

powered
by a string-theory propeller.

For Alice, not much changes.

She sits in the cockpit

and flies right over
the event horizon,

all the time seeing just the
central hub of her propeller.

And she meets
the same horrible fate

at the heart of the black hole,

this time accompanied
by some plane debris.

Bob's view is very different.

So, first he sees
the first propeller

come into existence.

Then later when it's
slowed down even further,

he begins to see
the outer propellers

come into existence
sort of one by one.

And the effect is
for the whole propeller

to get bigger and bigger
and bigger and grow

and eventually be big enough
to cover the whole horizon.

These two views no
longer seem so irreconcilable.

Alice is either squished
at the center of the black hole

or smeared all over
the event horizon.

Leonard has a name for this
new way of seeing things --

the holographic principle.

I began to think,
hey, wait a minute --

this sounds awfully much
like a hologram.

There's Alice at the center,

and if I look at the --
let me not call it the horizon.

Let me just call it the surface,
the film.

All you see is
a completely scrambled mess,

and somehow they're representing
exactly the same thing.

Leonard's idea --

that the event horizon
of a black hole

is a two-dimensional
representation

of a three-dimensional object
at its center --

solves the problem
of information loss.

Every object that falls
into a black hole

leaves its mark
both at the central mass

and on the shimmering hologram
at the event horizon.

When the black hole

emits Hawking radiation
from the horizon,

that radiation is connected
to the stuff that fell in.

Information is not lost.

In 2004 at a scientific
conference in Dublin,

Hawking conceded defeat.

Black holes
do not destroy information.

Leonard Susskind
had won the black-hole war.

But he'd done
much more than that

because the theory does not
merely apply to black holes.

It forces us to picture
all of reality in a new way.

It's as if there were
two versions

of the description of you and me
and what's in this room,

one of them being

the normal, perceived,
three-dimensional reality

and the other being
a kind of holographic image

on the walls of the room,
completely scrambled

but still with the same,
exact information in it.

That idea has now --
it's not an idea anymore.

It's a really basic principle
of physics

that information is stored
on a kind of holographic film

at the edges of the universe.

In a sense,

three-dimensional space is
just one version of reality.

The other version exists
on a flat, holographic film

billions of light-years away
at the edge of the cosmos.

Why these two realities
seem to coexist

is now the biggest puzzle
physics needs to solve.

One of the big challenges
that comes out of all of this

is understanding space itself.

Why is space three-dimensional

when all of the information
that's stored in that space

is stored
as a two-dimensional hologram?

A black hole
raises these challenges

and really sharpens
these challenges

because it's practically a place

where ordinary space
doesn't exist anymore.

So, if I'm asked questions
about how space emerges,

I will simply have to say,
well, we're thinking about it.

We don't understand it.

Black holes have been
a source of fascination

for almost a century.

We've thought of them
as time machines,

shortcuts to parallel universes,

as monsters that will one day
devour the Earth.

Well, any of these ideas
may turn out to be true one day.

But right here, right now,

black holes have a profound
effect on you and me.

Their shimmering,
holographic surfaces

seem to be telling us

that everything we think is here
is mirrored out there

at the very edge
of our mysterious universe.

-- sync, corrected by elderman --
-- for www.Addic7ed.Com --