All language subtitles for Through.the.Wormhole.S03E09.720p.HDTV.x264-ORENJi.HI

Freeman: Eternity.

It's an idea as old as religion.

Perhaps as old as humankind.

But what can modern science
tell us about the end of time?

Will the Universe end
in a cosmic apocalypse?

Could time keep on
ticking forever...

Or will eternity end?

Space, time, life itself.

The secrets of the cosmos
lie through the wormhole.

♪ Through the Wormhole 03x09 ♪
Will Eternity End ?
Original Air Date on August 1, 2012

== sync, corrected by elderman ==

The Apocalypse.

It's the day when Muslims,
Christians, and Jews

believe the world will come
crashing down around us.

Physicists now have their own
version of Apocalypse.

In fact,
they have several of them.

The sun will engulf the earth.

Our star will fall
into a black hole.

Our entire galaxy will collide
with another.

But what if everything
came to an end?

Destroyed in an Apocalypse
so complete

that time itself
would disappear.

I was just a young boy when time
ran out for my grandmother.

The sun continued to rise
and set each day.

The seasons cycled on.

I wondered if time for my
grandmother really had ended,

time when the Universe
carried on.

In fact, it seemed impossible
that time itself could ever end.

The ancient Greeks and Egyptians

thought of eternity
as a place outside of time.

They saw time as a giant circle,

mirroring the passing
of the sun overhead

and the rotation of the seasons.

But today, we have rolled out
the circle of time into a line

stretching from the distant past
to the far future.

Now we are forced to contemplate
whether this timeline has an end

or whether it can
stretch on forever.

But perhaps the riddle
of eternity

is something we've created
in our heads.

Anthropologist
Vera da Silva Sinha

and linguistic psychologist
Chris Sinha

spend their time thinking about
how people think about time.

Chris: We have very large-scale,
complex societies.

We could not make our society
take over

if we didn't have a calendar
and a clock.

So we think of time concepts
and ways of measuring time

as being what we call
a "cognitive technology."

It's a technology of the mind.

Freeman: But Chris and Vera
have discovered

this organized view of time
is not universal.

It's an insight they gained

from studying the language
and culture

of an indigenous Amazonian tribe
called the Amondawa.

The Amondawa people
live in Rondonia --

the state of Brazil.

They were contacted
by the Brazilian government

in 1984.

The Amondawa tribe
does not live by a calendar,

and they don't use clocks.

In fact, there isn't even a word
for time in their language.

If you ask
an Amondawa speaker

to give a translation
of the word "time,"

the nearest thing
that they can think of --

they will say "Sun."

Or they say
"raining season,"

or they say "summertime,"
but there is no...

There's nothing which is
abstracted from that, right?

To try and understand
the Amondawa's notion of time,

Chris and Vera had them arrange
a series of paper plates.

So, we found out
there is two seasons, yeah?

Rain season
and dry season.

So, and they would use
the plates

to symbolize how these seasons
are divided.

An Amondawa man
organizes the plates

not according to days or months
but by the natural events

that occur throughout
their two seasons.

For each one of these small
subdivisions of a season,

he'll tell a little story

about what kind of planting
and harvesting goes on,

also what fruits
are ripening

and what's going on in
the forest and in the rivers.

Is their level of the river
going up or going down?

This kind of thing.

Yeah. Yeah.

It's a way of mapping out time

that would make sense
to any farmer.

But in our industrialized
cultures,

a much more rigid system
has taken over.

We might arrange plates
in a line of seven --

one plate for each day
of the week.

Or we would divide a day
into hours arranged in a circle.

But the Amondawa don't arrange
events in any particular shape.

Vera: He's not really worried
about the shape of the events.

He worry about the contents
of each event.

They don't think of time
as being analogous

to a spacial dimension.

They don't think of time
being a sort of line

in which there is a future
that you look forward to

and a past
that you look back to.

In English, you can say, "Oh,
I look back to my childhood."

However, in Amondawa, you don't
look back to your childhood.

So, in your childhood,
you were there,

so you don't look
back anymore.

So [Chuckles]

The Amondawa
don't look back on a line

that traces their life
from past to present.

But in Western cultures,

we can't help but impose
this time geometry on our lives.

A person's life is like a line

that stretches
from birth to death,

and so we imagine
the Universe, too,

must have a timeline --

from its birth in the Big Bang,
14 billion years ago

to some far future date
when it will die.

There was no time
before the beginning,

and time will
eventually disappear

when the Universe meets
its apocalyptic end.

Theoretical physicist
Fotini Markopoulou,

like the Amondawa,
rejects this idea.

Well, if you are to say
that time will end,

you also have to say
that time began.

It's like death and birth.

You really can't have deaths
and no births.

So now you have to tell me

where time came from
if there was no time.

Freeman: Fotini is trying
to understand

the fundamental nature of time,

which in the microscopic world
of subatomic particles

becomes a tricky concept.

The theory of
Quantum Mechanics says

that particles don't interact

as if they are solid,
defined objects,

but as amorphous clouds.

A particle can be both there

and not there at the same time.

And it's impossible to say
when two particles meet

or whether they did at all.

If you try to apply the laws
of Quantum Mechanics

to large objects like people
or planets,

you can imagine some
very puzzling possibilities.

I'm sitting here,
and I'm talking to you.

Now, if by some accident,
in our Universe,

there was a huge black hole

that would suck me inside
the black hole,

according to Quantum Theory,

that black hole behind me
should be there and not there.

And, as a result, you are in
a position of our conversation

having happened or not happened.

Freeman: Many Quantum
physicists argue

this uncertainty over whether
the events really happened

shows that time cannot be
a fundamental thing

in the Universe.

It's something we've made up.

Albert Einstein disagreed
with Quantum Mechanics.

He believed time is real,

that it is woven with space
into the fabric of the Universe.

And, according to his disciples,

space and time were born
together in the Big Bang.

But Fotini thinks both
these views of time are wrong.

She thinks that time is real
and eternal.

But for that to be true,

we have to reimagine
what space is.

Okay, so let's say
that this is space --

the world we live in --

and the little red strings
are other stuff in our world.

And the net represents
the distances between us

in terms of connectivity.

So that means that,
for instance,

if we say that this is me

and this is my friend Oralia
and that's my fried Helmut,

it takes me --

one, two, three, four, five,
six steps to get to Oralia.

And then I need -- 1, 2, 3, 4,
5, 6, 7, 8, 9, 10,

11, 12, 13, 14, 15 steps
to reach Helmut.

Freeman:
But right after the Big Bang,

the net of space was not
spread out like this.

Perhaps, me here...

was actually just
one step away from Helmut

back in the early Universe,

and these two guys
were connected,

until everybody is really
on top of everybody else.

Freeman: In the very hot
and dense Big Bang,

everything is shrunk down
to a single point.

The idea of space
is meaningless.

But time, Fotini is certain,
always exists.

If we throw out space,
we get to keep time.

Time was always there before.
It will always be there after.

Freeman:
If Fotini is right,

time can indeed tick on forever.

But one scientist is deeply
troubled by an eternal Universe.

Because if time
never stops ticking,

our very existence
could make no sense at all.

Eternity.

It used to be a word
that only made sense in religion

or to people in love.

Now some scientists also believe
time really may last forever.

But if eternity does exist,

[ echoing ]
some very strange things...

[ Normal voice ] could happen.

Cosmologist Sean Carroll

from the California Institute
of Technology,

often takes a drive into
the mountains above Los Angeles

to get a better look
at the night sky.

And when he does,

he can't help but wonder what
that night sky will look like

trillions of years from now.

Carroll: Right now, we live in
a bright, comfortable Universe

with stars shining 100 billion
galaxies in the Universe

with 100 billion stars
in every galaxy.

But those stars
can't shine forever.

They burn up fuel.
They have a finite lifetime.

So, about 10 to the 15 years
from now,

those stars
will all have burnt out.

There'll be no more stars
shining in the sky.

Freeman: A million billion years
from now,

the only celestial object
remaining will be black holes.

Carroll: You might think,
okay, now we're done.

Black holes and empty space.

But those black holes evaporate.

They give off radiation,

and the black hole itself
shrinks away.

So it will take a long time,
but once that happens,

there's nothing left
but a thin gruel of particles.

And then we're faced
with the question,

well, what happens in that
infinitely long future period

after everything has
emptied out?

What is life like
in empty space?

Freeman: It turns out that empty
space is not truly empty.

In 1998,

astronomers discovered
a strange cosmic force

called "dark energy,"

an expansive pressure
existing everywhere in space.

Even an empty universe,
in the far future,

would be filled
with this energy.

And the laws of
Quantum Mechanics say,

wherever there is energy,

particles can spontaneously
appear out of nothingness.

Because that dark energy
is lurking in empty space,

there's a temperature.

The future of the Universe
is not at absolute zero.

There's a tiny
thermal fluctuation,

even in empty space.

If we imagine this oven
represents the whole universe,

we can look inside
and see things appear.

So if we wait a long time,
about 10 to the 10 years --

10 billion years --

we'll see a single,
lonely photon

propagating
through the Universe.

Freeman: But give
the Universe more time,

and more particles appear.

Eventually, after 10 to the
power 10 to the power 30 years,

something as complex
and unlikely

as a perfectly wired
human brain

could simply pop into existence.

And if you wait even longer
than that,

10 to the 10 to the 120 years,

we'll see an entire
new Big Bang,

an entire universe
fluctuating into existence

out of the surrounding chaos.

Freeman: For Sean,

these random fluctuations
present a big problem.

If the Universe lasts forever,

an infinite amount of time

means an infinite amount
of possibilities,

which means everything you could
possibly imagine

will indeed appear --

including
another version of you,

who thinks he got here first.

Many, many copies of me
will fluctuate into existence,

many of them with exactly
the same memories that I have.

There will be another version of
me that thinks the same as I do

and has the same set of memories
that I have.

But for most of
those versions of me,

they won't actually be embedded
in a sensible universe

with a big bang
and other galaxies.

Freeman:
Each one of these Seans

assumes that he is the first
version of himself.

They each think they grew up
in Pennsylvania,

studied at Harvard,
and wrote books on physics.

But they are really just
random fluctuations

that have popped into existence,

future imposters that
actually live in empty space.

The scenario that the Universe
just lasts forever

and there's all
these fluctuations

into everything we can
possibly imagine

means that we have no right to
accept and believe our memories.

If people and galaxies
and universes

can randomly fluctuate
into existence,

the conclusion is
that this can't be

the right picture
of the Universe.

Freeman: If dark energy
keeps on expanding our cosmos,

countless versions of all of us
will eventually come to be,

stretching from here
to eternity.

There's only one thing

that could prevent
such a preposterous universe...

A truly cosmic apocalypse.

[ Pop! ]

What does the word
"Universe" mean?

It used to mean "everything."

But now some scientists imagine
there is more to creation

than all the stars and galaxies
we could ever hope to see.

We might be just one tiny patch
of something much larger,

a multiverse,

a place that lasts forever,

and where a little Universe
like ours

comes and goes in the blink
of an eye.

Raphael Bousso is one of a new
generation of cosmologists

who grew up with the idea
that our Universe may not be

the be all and end all
of existence.

For him, other universes pop
into existence all the time

and exist inside
a colossal multiverse.

Bousso: The multiverse is made out
of many different regions.

These individual regions
can be so large that,

if you live in them,

you're really like a fish in an
extremely large tank of water.

You might think that there is
nothing else whatsoever.

Freeman: Imagine the Universe
we live in is like a balloon.

In the beginning,

it was just a miniscule piece
of compact space.

At the Big Bang,

a powerful force called
inflation took over,

expanding it in a split second.

14 billion years later,

we all live deep inside
its inflated walls,

blind to what's outside.

But Raphael believes inflation
is still at work

outside of our balloon.

It constantly takes tiny pieces
of space and expands them.

So, this room
is what we can think of

as the multiverse looking like,

where every one of these
balloons is a single universe,

and all these universes are here
because of inflation.

Freeman: Raphael's understanding
of inflation

stems from the view of reality
called "String theory,"

which holds that there are not
three dimensions of space...

but nine.

In our Universe,

six of the dimensions are curled
up billions of times smaller

than the smallest particle.

There might be some places

where all nine spatial
dimensions have become large.

There might be other places

where fewer than three
have become large.

So inflation stretches some,
but not necessarily all,

of the dimensions of space.

Freeman:
Just like an inflated balloon,

inflated dimensions of space

are intrinsically unstable
and will eventually...

re-collapse.

As I'm walking around this room,

you can see that these balloons
are popping...

ever so slowly,
one after the other.

There are a lot of balloons,

but if you train your eye
on one balloon,

that balloon eventually
is going to pop.

And just like that,

our piece of space eventually
is going to decay.

Freeman:
By studying how inflation

mutates the curled-up dimensions
of space,

Raphael has been able
to calculate

that the rate of creation
of inflated universes

is much higher
than their rate of decay.

So, even though universes
are going...all the time,

many more are always
being created.

So the multiverse keeps on
growing and will last forever.

This pattern is called
"eternal inflating multiverse."

If you were watching this room
from the outside,

time would be eternal.

This would continue forever.

Freeman:
This multiverse may be eternal,

but it's an eternity no one
can ever hope to experience

because no one can ever escape
the universe

they were created in.

You don't get the benefit
of seeing this eternity

of more and more inflation
and more and more balloons.

The speed-of-light limit

prevents you from seeing
all these other balloons.

You sit around
in this one balloon,

and sooner or later
it's going to go "pop."

[ Pop! ]

Freeman: If you live in a
universe, like everything must,

then Raphael believes your time
is definitely going to end.

[ Pop! ]

And all of the problems
of an eternal universe

that worry Sean Carroll

are problems our Universe
will never live to see.

We can calculate how rapidly
space will decay.

As long as that decay of
our Universe happens faster

than these unbelievably unlikely
events are going to happen,

then we know that
we don't have to worry about

copies of ourselves
coming into being.

When our Universe decays,
time really does end there.

[ Pop! ]

Is our universe destined to die
in a cosmic cataclysm?

Perhaps not.

Because time may not be
what we think it is,

and all of eternity
might already exist.

Physicists tell us that time
is the fourth dimension.

But it's not like the other
three that we move around in.

In space,

I could walk from here...

to here...

and then turn around
and go back again.

Time's dimension
seems different.

We only move through it
in one direction.

But there may be a way to grasp
all of eternity

if we stop thinking about
time as a dimension

and start thinking about time
as a projection

from the future...

[ Echoing ] to the past.

[ Normal voice ] For Harvard
physicist Andy Strominger,

the difference between
the future and the past

is a deep puzzle.

Because, according to
the known laws of physics,

they should be exactly the same.

There's a very basic principle
of physics

which begin with Newton.

The past determines the future,

and the laws of physics can be
run forward or backwards.

So, if I take this motion
of this pendulum

hanging from the pencil

and you run the movie forward
or backwards,

it looks exactly the same.

But there's a huge white
elephant in the room of physics,

and that's the Big Bang.

So, the cartoon picture
of the Big Bang

is that there was nothing.

Somebody flipped a switch,

and, all of a sudden,

all the something that
we know of was present.

So, the past of our Universe

and the future of our Universe
look fundamentally different.

Freeman:
To resolve this paradox,

Andy began to imagine
the dimension of time

a radical new way --

as a hologram.

Holograms are
two-dimensional plates

from which a third dimension
of space appears to emerge.

Andy wondered if he could
apply this idea

not to space but to time.

Perhaps a dimension of time is
just a holographic projection.

Time is a kind of illusion.

And the whole universe
is written at a hologram

that is sitting there
at the end of time

and projected backwards
through our present era

back to the Big Bang.

Freeman: The hologram that contains
everything the universe ever was

and ever will be is like
this intricate ice crystal.

According to Andy,

it sits in the far future

and projects information
back into the past.

Strominger: So, this sculpture represents
the holographic plate,

which contains all
the information

about the entire lifetime
of the Universe.

As I look at this very closely,
I can see more and more detail.

From far away,
or more accurately,

from further back in time,

there would be
less and less detail,

less and less information
present in the universe itself.

Freeman: The further you get
from a holographic plate,

the less information
you can read on it.

So, as we travel back in time
from our present day,

in a highly complex universe
of planets, stars, and galaxies,

we move to a simpler past,

to a universe the way it was
billions of years ago,

filled with nothing more
than clouds of gas.

Strominger:
And, eventually,

if you go far enough
back in time,

before the Big Bang,

there is simply nothing there
at all.

Freeman: Holographic time
is the only theory

that logically explains how
our Universe began from nothing.

Once you get too far back in
time from the holographic plate,

it cannot project back
any more information.

Before the Big Bang, there is
no information in the universe.

In a holographically-emergent
universe,

we don't have a Big Bang.

There isn't a special moment
when, all at once,

everything in the universe
came into being.

Rather, we have
an ongoing continual bang,

which started from nothing

and kept banging and banging
onto the future.

In the past, there was nothing.

In the future,
there is everything.

Freeman: The mathematics
behind Andy's theory

are highly complex.

Holographic time is not laid out
like any normal dimension.

As you go further and further
into the future,

the same increment of time moves
you less and less far forward.

So it would take an infinite
amount of time

to actually arrive
at the holographic plate.

Strominger: In this picture,

our Universe goes on forever
into the future

and gets bigger and bigger

and keeps growing
and creating new elements.

So we don't know that
it describes our universe.

We're very far from that.

But we do know that it is
something which can be discussed

with some mathematical precision
and consistency.

And so that's a starting point.

Freeman: Will our Universe
survive for an eternity?

It depends on who you ask.

Some say time
will go on forever.

Others are sure it must end.

But now another physicist thinks

we might be able to decide
who is right,

because the future
of the universe

may be traveling back in time
to meet us.

Is all eternity
already out there?

Could the present and the past
be echoes of the future,

rippling back in time?

If that's the case,

why is it you don't know
what I'm going to say next?

The fact is,

scientists think
they found evidence

the future really does affect
the present.

And knowledge about the fate
of the Universe

may already be
right in front of us.

Physicist Jeff Tollaksen
from Chapman University

thinks the future is very much
connected to the present.

The notions of time, eternity,
the end of time --

these are some of the most
profound questions

that we deal with
as human beings.

But you have to listen
very carefully

to what nature's
trying to tell you

to discover fundamental truth.

Freeman:
Jeff believes most physicists

have failed to fully understand
the nature of time

because of the way they insist
on doing experiments --

smashing particles together
in giant accelerators.

Maybe, instead of smashing
particles to bits,

we just need to give them
a little push.

What if more physicists took up
the gentle sport of curling?

Tollaksen: As you can see

what our athletes
are doing here,

they set the stone going
and they sweep a little bit

to try to direct the stone
going somewhere.

In a sense,

this sweeping is kind of like
a very gentle interaction.

You're not actually
touching the stone.

You're kind of making the ice
a little bit smoother

or melting a little bit

so it would tend to go
in one direction.

Freeman: Jeff believes
you can understand everything

about the way time really works
in the universe

by watching curling.

And you can begin
at the beginning,

with the idea of time
Isaac Newton had.

Tollaksen: So, the stone starts

from some definite place
in the past,

it goes to some definite place
in the present,

and it goes to a definite place
in the future.

So, from that perspective
of classical physics,

the universe looks like
it's a big machine,

like a big,
very perfectly tuned clock.

Freeman: But then,
about a century ago,

along came Quantum Mechanics.

It took away all that certainty
from the universe

by unmasking
the subatomic world.

If these curling stones
were atoms,

the rules of the game
would change dramatically.

Tollaksen: So, the quantum world
is different.

It makes different predictions

from the classical view
of things.

In Quantum Mechanics,

you could start these stones
the same

and you notice that, incredibly,
one stone goes to the left

and the other stone
goes to the right.

Freeman: In the microscopic
world of atoms,

nothing is known for sure.

Atoms are not solid,
defined objects.

They are waves of probabilities
that tell you where,

when you look for a particle,
you are most likely to find it.

But in the 1960s,
quantum guru Yakir Aharonov

dared to ask why atoms
are so unpredictable,

why it's so hard to pin down

what they're doing
at any given moment.

And the answer, he discovered,

was because the future
and the past are both involved

in creating the present.

Yakir showed that he could
reformulate Quantum Mechanics

in a way that dealt
with the past

and the future
on exactly equal footing.

Future information, which is
impossible to know now,

in principle,

maybe that's already relevant
to the present moment.

Freeman: Jeff and Yakir
have searched for evidence

of this revolutionary idea
for the past two decades.

They've learned to be very
gentle in their measurements.

A subatomic particle
will move or disappear

if it's observed directly.

It's as if they have to put
a particle in a box,

not look at it, and allow it
to carry on existing

as they spread out
a wave of probability.

When they do that,

they can begin to see the effect
of the future on the present.

So, we have the red boxes
that are going forward in time.

And now you have to think about
the backward evolving state.

So we're gonna represent that
by blue boxes.

Same particle, right?
We have one particle.

But coming from the future,
we're saying the present

is created out of a combination

of the forward evolving
and the backward evolving.

Freeman:
As radical as it sounds,

Jeff, Yakir,
and their colleagues

have now tested this idea
in the lab.

They give a series of
very gentle magnetic nudges

to subatomic particles.

They measure them at 2:00...

and then at 2:30.

They do this
over and over again.

Some but not all
of the particles

are also measured again at 3:00.

And what they found is that
taking their measurement at 3:00

seemed to influence
the apparently random readings

they got at 2:30.

The future seemed to affect
the present,

even though
it hadn't happened yet.

Tollaksen: If you're trying to
understand the present moment,

the past is relevant,
as we knew before,

but the future is just
as relevant to the present

as the past.

Freeman: So far,

these experiments have only
been carried out

on the microscopic level,

and the effects of the future
on the present are very subtle.

But to Jeff, it suggests
that buried somewhere

in the apparently random motion
of all the particles

in the Universe there is
such a thing as cosmic destiny.

Tollaksen:
There's an ocean flowing here.

There's a current flowing

from past to future
and from future to past.

Freeman: The Universe
may already have a destiny.

But can we mere mortals
ever know it?

One scientist thinks
he's discovered

the mathematical limit
of human knowledge.

Scientists have spent
3,000 years

trying to learn as much as they
can about the world we live in.

We've done pretty well.

We understand how planets,
stars, and galaxies work.

But to know the fate
of the entire universe,

just imagine how much more
there is to know.

So perhaps it's time to ask
ourselves an important question.

Are there some things we just
aren't meant to understand?

Theoretical physicist Tom Banks

believes the best way
to understand eternity

is to calculate how much
we can ever know.

And what we can know
is what we can measure.

So, you can see the Pacific
Ocean is here behind me,

and the Pacific Ocean is huge.

We couldn't possibly
measure it with rulers,

so we measure it
by using trigonometry,

all kinds of math.

Freeman: The Pacific Ocean
may be massive,

but we've traversed its length
and breadth

and mapped out all of
its 64 million square miles.

However, it isn't even a speck

compared with
the entire universe.

Banks: It is much too big for us
to physically measure.

Our Universe -- we can't even
get out there to most of it.

And we measure it by receiving
light from it,

sending light out to it,

and getting all kinds
of signals.

And we figure out
where things are,

how far away they are.

Freeman: But the Universe does
not just stretch out over space.

It also extends over time,

from its beginning
in the Big Bang

to the far future.

What would it take
to know everything

about such a vast place?

Tom thinks he can calculate
the answer to that question

using something he calls
"the theory of causal diamonds."

Banks: I'm drawing
a schematic diagram,

showing a causal diamond.

This is my past.
This is my future.

And this diamond represents

everything I could've done
experiments on

during that whole history
from the beginning to the end.

That region in space-time,

it forms a diamond shape

because light goes out
in sort of a cone like this,

and then if I look back
from the latest time,

it goes backwards in a cone.

You put those two
cones together,

and they're sort of
a diamond shape.

[ Clock ticking ]

Freeman: A causal diamond
marks the limit

of how much of the Universe
a measuring device

could ever hope to reach.

When that device sends out
a light beam,

it heads out into the Universe,

bounces off
some distant galaxies,

and finally returns to the
device billions of years later.

Tom has been able to calculate

that the amount of information
existing inside that diamond

is related to the area
of a sphere

that just fits around it
at its widest point,

a sphere he calls
"the holographic screen."

Banks: So now we can ask
the question,

suppose there was some machine
that lived forever

from the beginning of
the Universe to the end?

How big does the holographic
screen of the causal diamond

of that infinitely long-lived
detector ever get?

And it's very important,

because that determines
how much information

there could've possibly been

in this region
of space and time.

Freeman: Knowing absolutely
everything there is to know

about every atom and every
subatomic particle in existence

would mean collecting a truly
mind-blowing amount of data.

Banks: This number is 10
to the 10 to the 123.

It's a 1 with 10
to the 123 zeros after it.

That number is so huge
that it's hard to imagine it.

If I started trying to write
that number down

and I wrote a zero every second,

I would run out of time

long before the whole history
of the Universe,

and I would never get
to the end of it.

Freeman: But could
an advanced civilization

actually collect this much data

and know everything
about the Universe

and thus learn its fate?

The answer, Tom believes,

is contained
in this tiny cup of water.

So, in this little bit of water
I just got out of the Pacific,

there are sextillion atoms.

That's trillions of trillions.

If we wanted to measure
all those atoms,

we'd have to have
a really big machine.

We'd need a device that was
larger than the United States.

Freeman: But collecting data
on the entire Universe

is not just a monumental
engineering challenge.

The laws of physics actually
prevent us from doing it.

If we tried to measure
every atom in existence,

we would end up
using so much equipment

that we'd fill space with more
stuff than it could handle,

and the entire experiment would
collapse into a black hole,

destroying all that information
with it.

Whoa!

Tom has calculated
that we can measure no more

than 10 to the 10 to the 90 bits
of information

before we cause the entire
Universe to collapse

into a black hole.

This may seem like
a gigantic number,

but it is actually just
a tiny fraction

of 10 to the 10 to the 123,

which is all that
there is to know.

That number is so incredibly
smaller than this number,

that there's no hope
that any civilization,

no matter how sophisticated,

could possibly measure all
of the information

that there is in the Universe
throughout its entire history.

Freeman: All we can ever learn
about the Universe

is an impossibly tiny morsel
of what's out there.

And Tom argues,

trying to predict the future
based on such scant knowledge

is utterly futile.

So, perhaps we should quit
worrying about the end of time

and learn to live for the now.

Banks: It's natural for us
to want to know everything.

And we like to make up stories
about everything.

And those stories
are often wrong.

So people...are people.

We're finite.
We're not Gods.

We're -- we don't own
the Universe.

We're a very tiny portion
of the Universe.

And we've now discovered that
we're a much tinier portion

than we might've thought before.

We don't have the right,
in some sense,

to expect to know everything
that there is to know.

Will the Universe last forever?

Is eternity already out there,

projecting the present back
to us from the far future?

Or will a cosmic apocalypse
destroy everything

in the blink of an eye?

We don't know,
and we probably never will,

because some questions
require more knowledge

than we can ever get.

And maybe that's not so bad.

After all,
what fun would life be

if we already knew
how it was going to end?

== sync, corrected by elderman ==