All language subtitles for S02E07.da

Freeman: Our Universe.

It's awe-inspiring and baffling.

From colossal
explosions of stars

to the strange movements
of tiny particles...

...each new discovery

seems to reveal
another layer of mystery.

Our understanding
of the world around us

has taken us from the Stone
Age to the Silicon Age.

Now ironclad laws of physics
are breaking apart.

What we believe is reality
may not be real at all.

The future of humanity
depends on our discovering...

...how the Universe
really works.

Space, time, life itself.

The secrets of the cosmos
lie Through the Wormhole.

Think of existence

as an enormous web
that we're all woven into,

but we can't see
the whole thing.

We just see the patch
where we are standing.

We can't see
the whole of reality.

But what if we could see it all?

What if we could understand

how the whole of
creation joins together?

The rewards of finding this
equation would be enormous,

a revolution in science

far beyond anything
that has come before -

a great leap forward

that will transform
life on Earth

and ensure our
survival as a species.

But what hope do we
mere mortals have

of uncovering the hidden
secrets of the Universe,

of knowing the mind of God?

I remember
my first day of school,

the day I was supposed to
start learning about the world

and how it works.

I made it about 20 yards
to the schoolhouse,

then I froze.

What hope did I have

of understanding
everything or anything?

My mind reeled.

I ran back home.

I wonder if scientists feel
much the same way.

There is so much we don't know

about why the Universe
functions the way it does.

Imagine trying to play
a game of chess

if you don't know the rules.

You might figure
out some moves,

but a lot of it
would make no sense.

Once you know
the rules, though,

you can begin to move
the pieces with purpose.

Science is our means
to discover those rules,

and so far we've revealed
quite a few of them.

But what if we've
got them wrong?

Deep in the basement tunnels
of Purdue University,

scientists Jere Jenkins
and Ephraim Fischbach

have discovered

that one of the supposedly
unbreakable laws of physics

is broken.

It began with a mystery.

Man: I'll come out
and set up a few tethers

and receive some tools,

then he'll come out
right after me.

Jenkins: The second week
of December of 2006,

astronauts from
the space shuttle

were up in the International
Space Station,

and everybody was
out on an E.V.A.,

and there was a solar storm.

Because the astronauts
were all out there,

the solar storm was big news.

Sitting there and watching
that news story, I thought,

"Wow, wouldn't that be funny

if I saw that appear
in the data?"

Freeman: Jenkins studies

a powerful source of
energy we can't see

but is all around us -

radioactivity.

Every second of every day,

the Sun sprays out showers
of radioactive atoms.

These atoms are unstable.

They spit out energy
until they burn away

in a process known as
radioactive decay.

Radioactive decay is
supposed to be a random process

that cannot be
affected by anything.

Jenkins:
In early December of 2006,

we're plotting this.

It's a nice, straight line.

It's following
exactly like it should,

but then on December 13th,
a flare happened.

And we see that the decay
has actually departed

what the standard decay line
should have been,

and it departed it
for quite some time.

This is actually the space
of about four days.

It appeared, or so it seemed,

that something
may have been changing

this radioactive-decay process,

which nothing
is supposed to change.

Freeman: Fischbach,
a theoretical physicist,

struggled with the huge
implications of this finding.

Knowing how fast
radioactive particles break down

is critical for nuclear power,

weapons, electronics,
and medicine.

Could it be that a concept
so uniformly accepted

and central to modern
life was wrong?

The idea that nuclear decays

cannot be influenced
by an external influence

is so fundamental to so many
aspects of quantum physics,

nuclear physics,
elementary-particle physics,

that changing that would likely
have a significant change

on our understanding
of the Universe,

as well as on practical
applications.

Freeman:
Still reeling from this shock,

Jenkins and Fischbach
uncovered another mystery.

Radioactive decay
was not just being affected

by the solar flare.

The discharge of radioactive
particles appears to change

depending on how close
the Earth is to the Sun.

Fischbach: When the Earth
is closer to the Sun,

around January 4th,

the rate of radioactive decay
seems to be faster.

And when farther away,
the rate seems to be slower.

Now, we can illustrate this
in the following way.

I represent the Sun,

and Jere is gonna
represent the Earth,

and the bucket represents

a sample of radioactive
radium atoms.

And you'll see that
as Jere moves in an ellipse,

where he's closer to the Earth
around January 4th,

more tennis balls
are thrown out,

meaning more particles come out
than happen around July 4th.

Freeman:
This small change in numbers

could have big consequences.

Cancer patients receive
very tiny doses of radiation

to kill their rebel cells.

If the strength of that
radiation changes seasonally,

they might get too little
or too much of a dose.

Knowing the difference
could save lives.

But the duo's
most important discovery

could secure the future
of the human race.

40 hours prior to the
actual time of the flare,

we saw the decay rate change
and actually leave the line.

After the flare,

it started to recover
and move back toward the line.

So, this possibly gives us
the opportunity, then,

to predict when these
solar flares are happening.

Freeman: A large solar
flare could wipe out

every one of the nearly 3,000
satellites orbiting the Earth.

In a flash,
we would lose the Internet,

GPS, television,
radio, telephones,

and the systems
that control our power grids.

Knowing a flare is coming
could avert a global apocalypse.

If this phenomenon is real,
as we believe it is,

then it's essential to
understand how this is happening

because this will certainly be

a part of a bigger puzzle
that we must understand

to put all this physics
together.

Freeman: We're groping in
the dark of the vast Universe,

thinking we have uncovered
its deepest truths,

then finding we still
have much to learn

about the rules of nature.

And nature does not
make things easy for us.

Down at the smallest scale
of existence,

deep in the weird world
of quantum mechanics,

it seems to play
by two different rules

at the same time.

And the deeper we probe
into its mysteries,

the more we are forced to ask
not just how the Universe works,

but whether anything is real.

Quantum mechanics
has transformed the world.

We owe most of our
amazing technology

to its explanations of how
extremely small particles...

behave.

But we don't really
understand it.

In the quantum world,
nothing seems to make sense.

Reality stops being... real.

This mystery is our
greatest obstacle

to unlocking the secrets
of the Universe.

If we can solve it,

we may hold the keys
to creation itself.

Vienna, Austria,

is arguably the birthplace
of quantum mechanics.

This is where you will find

the leading quantum
experimentalist in the world,

professor Anton Zeilinger.

Zeilinger: When I first heard
of quantum mechanics

when I was a student,

I was immediately struck
by three things -

first, its unbelievable
mathematical beauty.

Secondly,
by the incredible precision

to which the predictions work.

And thirdly,

by the fact that...
it doesn't make sense.

Freeman: Quantum mechanics
describes the behavior

of all the tiny particles
that everything is made of.

This knowledge
has given us computers,

nuclear power, satellites,
advanced medicine -

most of the great leaps forward

humanity has taken
in the past 100 years.

But the quantum world
seems to run contrary

to everything we know
about the laws of nature.

Simply put, down where things
are very, very small,

the Universe follows
a different set of rules.

Consider the phenomenon
of quantum nonlocality,

when two tiny particles
instantly share information

across vast distances.

If there were quantum dice,

it would mean
that if I throw one die here,

it shows a certain number.

The other dice thrown
at some distant location

would show the same number.

How can that be?

Quantum mechanics
describes it very well.

Freeman: Time and again
Zeilinger has proven

that no matter how extreme
its predictions,

quantum theory works
even though it shouldn't.

And perhaps the ultimate proof

of just how unsettling
quantum mechanics can be

is something called
the double-slit experiment.

It will make you question
whether reality exists at all.

This simple configuration

shoots particles of light
called photons

one at a time through
two tiny slits in a screen.

Zeilinger: There's a laser
which produces light.

This light is attenuated

such that only one photon
at a time emerges.

These photons pass through
a two-slit assembly,

and then we have a camera
which registers the pattern

behind the two-slit assembly.

So, what we see is
that the photons arrive

one by one on the screen -
some here, some there -

and it looks pretty random.

Freeman: Since the photons
travel one by one -

some through this slit,
some through that slit -

you would expect them to leave

a pattern of two stripes
on the wall,

and you would be wrong.

They mysteriously create
a band of stripes.

This is what
you would expect to see

if a constant beam of light
shined through the two slits.

It would spread across
the wall like a wave.

So, how can single
bullet-like particles of light

create a wave pattern?

This could only happen

if the particles go through
both slits at the same time.

In other words,

the particle is
in two places at once.

But strangest of all
is what happens

when you put detectors
next to the slits.

When the photons
are being watched,

the wave pattern disappears.

Take away the detectors,
and the wave pattern comes back.

This suggests that we can change
the way reality behaves

just by looking at it.

Does this mean
that reality itself

is not real?

The modern answer is that
the path taken by the photon

is not an element of reality.

We are not allowed to talk about

the photon passing through
this or this slit.

Neither are we allowed to say

that the photons
pass through both slits.

All this kind of language
is not applicable.

Freeman: So, do we just
keep reaping the benefits

from quantum mechanics

and accept that, deep down,
nature plays by a set of rules

that will forever remain
a mystery?

Zeilinger:
The interesting message here is

that we have quantum physics now
around for nearly 100 years,

and we are still working
at the foundations.

And that tells me
that when we find it,

it will be an
absolute revelation.

It will be something different
from what we have been thinking.

If the quantum theorists
are correct,

we will never understand

the fundamental level
of the Universe.

Our hopes of finding
an ultimate theory will fail,

and the human race

will hit a roadblock
it can't break through.

But what if they're wrong?

What if the truth
about what happens

deep inside you, me,

and everything else
in the Universe

is there if we're willing
to look for it?

For most of the 20th century,

scientists believed quantum
physics could not be explained,

that we would just
have to accept

that we'll never know
why things behave as they do

down at the deepest
levels of existence.

But now a growing band
of rebel scientists thinks

there may be
a logical explanation

for quantum weirdness after all

and new hope for revealing

the ultimate truth
of our Universe.

The trail begins here...

with a drop of silicon.

In his Paris laboratory,

physicist Yves Couder
and his team

conduct an amazing series
of experiments.

They are observing the
behavior of silicon droplets

bouncing in lockstep
on a vibrating plate.

Couder:
The liquid of the drop

never touches the liquid
of the substrate.

So, they're always
separated by a film.

And, in fact, it is stable.

You can keep the drop bouncing
on the liquid surface

for several days if you wish.

Freeman: Using a camera that
shoots 1,000 frames per second,

Couder has discovered
that these droplets

mimic behavior seen
in the quantum world.

And that shouldn't be possible,

because the quantum world
and the large-scale world

play by two different
sets of rules.

Yet here we see a single
droplet moving randomly

like a quantum particle,

but behaving like
a quantum wave.

If you watch this carefully,
you'll notice that the wave

appears to be
guiding the droplet.

In fact, the wave fields
around the droplets

develop a memory of the trails
they have followed.

Despite their random behavior,

they follow a small number
of paths.

Again, this is eerily similar

to the behavior
of quantum objects.

This runs so contrary
to popular belief

that, at first, Couder refused
to believe what he was seeing.

Couder:
In any physics experiment,

you only see what you
are prepared to see.

Of course, it was very obvious
that there was a memory,

but it took us
some time to realize

that it was that
that we were observing,

because you have to
adapt to this new idea.

Freeman:
Perhaps most revealing of all,

Couder has reproduced
the double-slit experiment

using his bouncing
silicon droplets.

The mystery
of quantum mechanics is,

how can things like electrons

sometimes behave like particles
and sometimes behave like waves?

Perhaps this is the answer.

They are particles and waves.

Of course, this system,
though small, is not quantum.

Couder: Our system is not
a model of quantum mechanics,

but is an association
of a particle and a wave.

And some of its
properties are similar

to the properties that are
observed in quantum mechanics.

Freeman: Couder won't claim
that his experiments show us

what is really happening

down at the deepest
layers of existence.

But this man will.

To him, those droplets
are more proof

that the quantum world
makes sense after all

and that reality really exists.

Antony Valentini
of Clemson University

is a quantum heretic.

He loudly proclaims

that physics went off
the rails in the 1920s

when it embraced the doctrine
of quantum uncertainty,

which says that nothing is
real until we look at it.

Valentini champions the theory
that got left behind.

It was created
by one of the pillars

of early 20th-century physics,

Louis De Broglie.

Valentini: Louis De Broglie's
original idea is

an electron is both a wave
and a particle all the time.

It's not the case that,
well, sometimes it's a particle,

sometimes it's a wave.

There is a wave guiding
a particle at all times.

And De Broglie
called this a pilot wave.

Freeman: In quantum theory,

there's something called
the probability wave,

a purely mathematical object
that tells you the chance

of finding an electron
at any point in space.

Pilot wave theory

treats this wave
as a real physical object.

Valentini:
So, a simple analog is a bottle.

Someone is on an island,
and they want to send a message.

So they write something
on a piece of paper,

put it in a bottle, close it,
and throw it in the ocean.

And water waves
simply push the bottle along.

Freeman:
There is a crucial difference

between the waves we know
and the pilot wave.

According to the theory,

pilot waves exist
in hidden dimensions of space

beyond the three we know.

If true, this means that,

contrary to the accepted
theory in physics,

quantum objects obey
the same rules as large objects.

They do not exist
in two places at once.

They're part of the real world.

Valentini: I think
that quantum mechanics itself

is not even a candidate

for the truth about
the microscopic world,

because it simply doesn't
attempt to describe

precisely what
the microscopic world is.

The mere fact that there are
different theories

about what the answer might be

doesn't mean
that there's no answer.

And eventually one of them
is found to be the correct one.

Freeman: To understand
how the Universe works,

we need to unlock

why the quantum world
is so different

from the world we know.

It is an unsolved mystery

that affects every
single person on Earth,

and this man
thinks he can solve it.

The more we understand the inner
workings of the Universe,

the more we humans are rewarded
with new medicines,

new technologies,

and undreamed of
improvements in our lives.

But some say
we're a long way off

from unlocking the
Universe's deepest secrets.

We want definitive answers.

What we have are
mysteries upon mysteries.

And one of the
greatest mysteries

is how the big stuff

and the small stuff
in the Universe fit together.

Two well-tested theories
describe how matter behaves -

relativity theory,

which governs
the physics of the large,

and quantum theory,
which describes the very small.

If they were a couple,
relativity would be a logical,

pocket-protector-wearing
engineer

who strictly follows
the speed limit of light.

Quantum theory would be
his volatile artist wife

who seems to be
everywhere at once.

On paper, they don't get along.

But in the real world,
they are a happy pair.

And like some real-life
odd couples,

no one understands why.

The mystery
boils down to gravity.

Gravity dominates
the world we know,

and thanks to Newton
and Einstein,

we understand it pretty well.

But physicists have no idea
what role gravity plays

in the quantum realm

or its effect on space and time.

If we crack this mystery,

we will finally know
if it is possible

to travel back in time
or through a wormhole.

Petr Horava has
a history of exploring

the wild frontier of physics.

Now he's tackling
quantum gravity.

Horava: So, how do you reconcile
quantum mechanics and gravity?

There are several different
ways it can happen.

Either quantum mechanics
is stronger and wins

and gravity has to be modified,

or quantum mechanics
has to be modified

and gravity stays the same as in
Einstein's general relativity.

Freeman: Petr feels the key is

to watch how things
change in scale

between the upper
layers of nature,

where gravity holds sway,

and the quantum
layers down below.

Nature organizes itself
in layers of structure,

and you see more and more
layers as you zoom in

and gain a better resolution
of how you view the system.

It's one of the most important
theoretical concepts

in modern physics.

Freeman: To Petr,
nature is an archaeological dig

that we're slowly
excavating layer by layer.

Right now, we're only capable
of uncovering a small part

of the vast and complex
ultimate truth.

But we can learn a lot

by comparing
the layers we can see.

In this picture,
the two images of Mona Lisa

represent the two faces
of space-time -

space and time.

They look the same

when we look at it
at large scales,

but perhaps when we zoom in

and look at the system
at much smaller scales,

it could be
that space and time scale

in a very different way.

This could be the missing
piece of the puzzle

of quantum gravity.

Freeman: Petr suspects
that as you shrink down

to the smallest and deepest
level of existence,

space begins to stretch
at a different rate from time

until they tear apart.

Think of space-time as analogous
to this sheet of paper.

At microscopic scales,

it's smooth and geometric,
two-dimensional.

But if you tear the piece
of paper into two halves

and look at the edge
of the paper -

zoom in, zoom out -

the structure
is similar to itself,

but only if you stretch
in the horizontal direction

with a different rate

than when you stretch
with a vertical direction.

Freeman: From a distance,
the tear looks smooth.

But close up,

you can see mountains
and valleys along the edge.

Similarly, space and time
seem perfectly joined

from a distance.

But close up,
you can see the separation.

Petr thinks this tearing apart
of time and space

at the microscopic scale
is precisely why

the strange rules
of quantum mechanics emerge.

If space and time are unhinged,

particles can't be in a specific
place at a specific time.

Hence, fuzziness
and uncertainty.

Unraveling the enigma
of quantum gravity

is a major hurdle in our quest

to understand
how the Universe works.

But it shrinks
against the magnitude

of the biggest mystery
facing humanity.

95% of the Universe is missing.

This woman may know
where and what it is.

The more we peel away
the layers of nature,

the more we realize
that something is missing -

something big.

An enormous chunk
of the Universe

seems to be invisible.

We can't see it, hear it,
or detect it in any way.

But if we want to unlock
the secrets of the Universe,

if we want to
advance as a species,

we have to find out
what and where it is.

The Universe began
with the Big Bang,

a shattering explosion
of raw energy.

That energy burst outward
in a mass of superheated plasma.

As it cooled,
it began to clump together

into all the material
in the Universe -

the solids, liquids, and gases
that everything is made of.

To crack the cosmic code
that underlies our Universe,

we have to understand energy
in all its forms.

But what if almost
95% of the Universe

is made of a form of
energy we can't see

and don't understand?

These are the kinds of questions

confronted daily
in Geneva, Switzerland,

the home of the world's largest
particle accelerator -

the Large Hadron Collider -

and also hundreds of physicists.

Clare Burrage is one of them,
but she's hardly typical.

Young, female, and
an accomplished figure skater,

Clare is trying to solve
the vast mystery

of the missing Universe.

Burrage:
So, if we think about the Sun,

the light from the Sun carries
energy to us here on Earth,

and we can feel the warmth
of the Sun on our skin

on a nice day.

But Einstein tells us
that what's happening is

that energy and mass
are the same thing.

So, in the center of the Sun,

mass is being turned
into energy,

and that's what's
transmitted by the light

here to us on Earth.

So, the energy from the Sun

we know and we
understand very well,

but it seems like
there's another form of energy

out there in the Universe
called dark energy

that we don't understand at all.

Freeman:
Accepted laws of physics dictate

that the expansion of
the Universe after the Big Bang

should be slowing down.

But recent astronomical
observations have revealed

that the expansion
is rapidly speeding up.

Some unexplained form of energy
is pushing galaxies apart.

Burrage:
So, at the moment,

I'm moving forward even though
I'm not doing anything

because of the force of gravity.

But if I were in space,

where there are no forces
acting on me,

I shouldn't be moving at all.

If I'm moving forwards,

then there has to be something
very strange acting on me,

and this is what we
call dark energy.

Freeman: How much of
the Universe is dark energy?

Put it this way.

Here's the Universe.

This sliver, 4.6%,
is all the matter we can see.

Near-massless particles
called neutrinos

take up another 0.4%.

We think that
something called dark matter

accounts for another 23%.

Dark energy is the remaining 72%

of the mass and energy
of the Universe.

We cannot see it, touch it,
taste it, or detect it,

but cosmologists are
certain it is there.

Without dark energy,

gravity would cause the Universe
to collapse in on itself.

Clare suspects
that dark energy is a by-product

of a radical new piece
of physics,

an undiscovered particle
called the chameleon.

These mysterious particles

actually carry an entirely
different basic force

than the four
that physicists know about,

a fifth fundamental force.

Burrage:
In physics as we understand it,

there are four forces.

So, they are gravity,
which holds us here on Earth.

There are the electric
interactions between atoms

and the strong and weak forces

that control what happens
in atoms.

And so if there is
something new,

a new particle
like the chameleon,

like dark energy,

it's going to look to us like
there's a fifth force out there.

This force carrier
is called a chameleon

because it can change
its appearance.

When it is heavy,

it becomes sluggish
and ineffective.

When it is light,

it can zip around much faster
and become stronger.

How heavy it is
depends on its environment -

how much stuff is around it.

Burrage: So, here on Earth,
there's a lot of stuff around,

a lot of matter,

and the chameleon becomes
very heavy, very massive.

It doesn't interact with
the things around it very much,

and that's why we don't see it
in our everyday lives

and in experiments
here on Earth.

But in intergalactic space,
where there's almost nothing,

the chameleon
becomes very, very light,

and it can interact with things
over huge distances.

And that's why
it can drive the acceleration

of the expansion
of the Universe.

Freeman:
This shape-shifting property

explains why the chameleon
has yet to be spotted

in our particle accelerators.

It should be everywhere -

inside you and me
and far out in the cosmos.

But how do we detect
a master of disguise?

Burrage: The chameleon
shows up in experiments

on really tiny scales
and on really huge scales.

So you can look for it

in the ways that particles
behave in colliders

on really tiny scales.

But also,

it affects
the way that light travels,

and so we can look
on very large scales

at how light from stars
comes to us

and whether we can see

the effects of the
chameleon there.

Freeman: Our slow
and steady understanding

of electromagnetism
and the nuclear forces

has transformed our lives,

from electricity
to telecommunications,

transportation to warfare.

What benefits could
dark energy bring us?

It's very hard to say now

how a better understanding
of dark energy

is going to make
people's lives better.

But in the past,
understanding things better

has always led to
benefits for mankind.

So, in some ways,
understanding dark energy,

for understanding the Universe,
it's more important

than understanding the physics
that we know here on Earth.

The particles that we understand

make up about a percent
of the Universe as we know it.

Dark energy is a massively more
important contribution.

Freeman: Dark energy
is the unknown variable

in our quest to crack
the cosmic code...

to find a set of equations

that describe how the Universe
really works.

But this man says
that doesn't go far enough.

He believes equations don't just
describe the Universe.

Equations are the Universe,

and we are all
living inside them.

We are hunting
for an ultimate equation,

the theory of everything

that will explain the
mechanisms of the Universe

and revolutionize life on Earth.

One man believes
that equation exists

and the solution is
the Universe.

According to him,

the equation of everything
is everywhere you look,

and we are all part of it.

Max Tegmark lives
in Winchester, Massachusetts,

a northern suburb of Boston.

He's an outdoorsy sort

who likes to go on long walks
and think.

But Tegmark's thoughts
are a bit more exotic

than your average power
walker's ponderings.

Tegmark:
I think the reason

our Universe is
so well-described by math

is that it is math,
in the sense that we are living

in a giant
mathematical structure.

So, the reason
we physicists have discovered

all of these equations
which describe our world so well

is simply because
these equations

can approximately describe

the true math
which is our reality.

Freeman: To Tegmark,

equations are windows
on the Universe,

and the Universe is pure math.

Tegmark: At first glance,

our Universe doesn't seem
mathematical at all.

We don't have big numbers
written visibly in the sky.

But if we look more closely,

we find mathematical patterns
and shapes all around us.

Like, if I mess around
with my garden hose here...

the water makes this very simple
shape called a parabola,

which has this extremely simple
mathematical equation,

"Y" equals "X" squared.

This mathematical shape,
the parabola,

is really built into nature
at quite a fundamental level

because it describes
the motion with gravity

of any object,
regardless of what it's made of.

When we look around us
in the Universe,

we see shapes everywhere.

We see that all the planets
are going around the Sun

in a shape called an ellipse.

It just looks like
the stretched circle.

And anything orbiting anything
out there in the Universe,

why is it always that shape?

You know, not a figure eight
or a square?

As soon as we scratch
beneath the surface,

we start to discover all these
patterns and regularities

and even numbers.

Like, if I just pick up
some sticks here,

and I ask, like,
how many sticks can I put here

which are perpendicular
to each other?

I get a number.
I get three.

We have a fancy number
for this in physics.

We call it the
dimensionality of space.

And these numbers that are built
into nature are very important,

because if you tweak
them a little bit,

if you say the proton isn't

1,836 times heavier
than an electron,

but 5,000 times heavier,
for instance, we would die.

In fact, if you change
many of the numbers

by just a few percent,

the Sun might blow up
or suddenly atoms would collapse

and life as we know it
just wouldn't be possible.

So, not only
are these numbers there,

but they're extremely important

for understanding
the very essence of our reality.

Freeman: This brings us back
to an uncomfortable notion

suggested by the prevailing
theory of quantum mechanics.

At the deepest level of reality,

nothing is solid.

There is only information -

numbers adhering
to a set of rules

we don't yet understand.

Tegmark: The only properties
an electron has

is a bunch of numbers.

We physicists have names
for them like spin and charge,

but they're really just numbers.

There's really nothing there
at the bottom level

except numbers, except math.

Freeman:
Math may be the ultimate truth,

but given our limitations

and how vast and strange
so much of nature seems to be,

is it even possible
to solve this problem?

Can we ever know
how the Universe really works?

There's certainly no guarantee

that we'll find
the ultimate equation,

but I think we do
have a shot at it.

It's really remarkable how far
we've come as a species

in the last 100 years,

beyond our wildest dreams
in understanding stuff.

And there's no better way
to guarantee we're gonna fail

than to not try.

If I'm wrong

and there is something
inherently nonmathematical

about the Universe,

then physics
is ultimately doomed.

We're gonna reach a roadblock

beyond which
you just can't proceed.

Whereas, if I'm right,

that would actually be
a very happy situation

where there is no roadblock

and our progress would only be
limited by our own imagination.

Will we ever see
the entire web of reality?

Can we find,
and will we understand,

the ultimate truth?

Right now,
we are like archaeologists

who have uncovered a small
triangle buried in the sand,

the tip of an enormous pyramid
that we can't yet see.

Perhaps it's presumptuous

for human beings to think
we ever will.

But we continue to
uncover the truth,

bit by bit, piece by piece.

If we keep digging,

we may finally reveal
the full beauty of creation...

and perhaps steal a glimpse
into the mind of God.