Space's Deepest Secrets

The white hole.

One of the strangest objects in the universe.

Black holes are weird,

but white holes... They're way weirder.

Science predicts they should exist.

But these astronomical wonders are so mysterious,

no one is sure what they really are.

How do you start looking for something that you have no idea

what it might possibly look like?

Today, astronomers race to find the clues

that can unlock the secrets of white holes.

Can unexplained energy bursts deep in space

be a sign of these enigmatic objects?

To this day, we still don't know what caused it.

And could a white hole be a gateway to a different time

and space?

White holes sound like pure science fiction,

but they could be science reality.

We venture to the farthest reaches of the universe,

go back in time to the moment of its creation,

and journey through the monster at the center of our galaxy

to hunt for the truth about white holes.

Our universe is home to a mind-boggling array

of mysterious objects.

Stars so magnetic that they rip apart atoms.

Planets where diamonds fall as rain

into oceans of liquid hydrogen.

Threads of dark matter, billions of light-years long

that weave the entire universe into a vast cosmic web.

Astronomers have unlocked many of the secrets

of these weird cosmic creations.

But one theoretical object in the vastness of our cosmos

confounds the greatest minds in science.

It's called

the white hole.

A white hole is a super powerful stream of energy.

That pours from an intensely bright point in space.

It emits radiation so powerful that nothing can venture near.

A white hole certainly has to be

one of the most mysterious objects

that the universe could possibly conjure up,

but you wouldn't want to get too close.

I think if one went off anywhere near in our galaxy

and it was pointed at us,

you wouldn't even know it was coming.

The earth would be fried by the light coming out in an instant.

No astronomer has ever seen a white hole.

Does this galactic monster really exist?

A clue lies inside the brilliant mind

of the world's most famous physicist.

Einstein is truly a cultural icon.

If somebody said the word "genius" to you,

one of the first things you might think of

is the face of Albert Einstein, his crazy hair and all that.

But all of that overshadows just what a profound effect

he had on modern science.

Over a century ago, Einstein comes up with a theory

that changes everything we know about the universe.

Einstein's general theory of relativity

tells us that the universe is not as it seems.

It puts limits on what we can do in space and time,

how fast we can travel.

It basically affects everything we understand

about the universe itself.

Einstein's theory stretches space, literally,

and predicts the existence

of one of the strangest objects in the universe.

General relativity combines space and time into space-time,

the fabric of the cosmos,

which is flexible.

Extremely heavy objects can actually warp space-time

to create gravity Wells around them.

The more massive the object,

the bigger and deeper the gravity well.

But the theory predicts one object

that could stretch space-time to its limit,

a point so dense that nothing escapes its thrall.

The name for this bottomless gravity well is a black hole.

It is an object that transforms physicist's ideas

of what's possible in the universe.

Einstein's theory also predicts another mind-bending object.

The equations of general relativity

allow us to push the limits of the universe as far as we can.

What if there's something that's like the opposite

of a black hole... a white hole?

Well, the mathematics of general relativity

allow for that, as well.

Einstein's equations make it possible

for white holes to exist.

How would they work?

Clues to how they might operate could lie

in the extreme physics of their theoretical opposite.

A black hole.

In the 100 years that follow Einstein's theory,

definitive proof of a black hole's existence,

a photograph, eludes astronomers.

Up until now,

really what we've had is indirect evidence.

Wouldn't it be amazing

to actually see the black heart of it itself?

How can astronomers see a black hole

to take a picture of it?

Fortunately, Einstein's theories predict

that black holes and white holes both share a common feature.

Out of these complex theories come these

mathematical predictions that sound like science fiction,

but in reality, they give us actual things

to search for in the universe.

One of those science-fiction-sounding ideas

is something called the event horizon,

this purely mathematical boundary

that is the prediction from the theory.

And yet this is an actual physical surface

that we can search for.

The event horizon of a black hole is

the invisible boundary beyond which nothing,

not even light, can escape.

In theory, it should leave a Mark that astronomers can see.

As matter falls into a black hole,

it gets superheated and when he gets superheated,

it glows and it gives off light,

so we can find it.

If this direct evidence for the existence

of black holes is out there in space,

then it is possible to unlock what makes black holes tick

and use this information to unravel how white holes work.

Photographing a black hole is a huge challenge.

The strength of a black hole

doesn't come from its size.

It comes from its density.

You actually want to compress as much matter as possible

into a very, very small volume of space.

And what happens is that makes black holes very small

and that makes them hard to see.

And in fact, even the biggest black holes,

if you want to see them,

you're going to need a telescope the size of the earth.

In 2017,

eight radio telescopes across the globe joined forces

to take a first picture,

from Arizona to Hawaii

to Europe,

even the south pole.

All aim at the exact same spot...

The heart of a galaxy 55 million light-years away.

This is the picture that the telescope captures,

the first ever photograph of a black hole.

This image just makes my jaw drop.

It's not some myth. It's not some story.

It's real data.

Now that we have this image, that's it.

How can you be a black-hole denier?

That would be as crazy as saying the earth is flat.

The image proves that black holes exist.

It also reveals how the event horizon

of a black hole works.

And this is the first step

to unlocking how a white hole operates.

That circle is actually from a disk of material

swirling around the black hole.

Any light inside of that region circles around the black hole

a few times and then falls in.

So it actually can't escape to reach our telescope,

and it looks dark.

The photograph shows that the event horizon really

is the point of no return for both energy and matter.

What does reverse-engineering the event horizon

of a black hole tell us

about how their theoretical opposite, a white hole, works?

And could an unexplained burst of energy

lead astronomers to the first ever sighting of a white hole?

Astronomers are on the hunt

for the most elusive object in the cosmos...

The white hole.

Einstein's theory of general relativity predicts

that it can exist.

Can reverse-engineering its twin, the black hole,

reveal how a white hole works?

Physicists believe that a simple stream of water

unlocks the mystery of how a white hole behaves.

It turns out that you can demonstrate the rough behavior

of a white hole in your kitchen sink.

So if a black hole is a region of the universe

that something can only ever enter and never leave,

a white hole is the opposite of that.

It's a region that something can only ever leave

and nothing can ever enter.

The falling water makes a circle

of fast-moving liquid when it hits the plate.

Outside is an area of slow-moving water.

The boundary acts like the event horizon of a white hole.

It creates this continuous,

outward-flowing cascade of water that serves as a kind of barrier

for anything trying to enter.

Energy or matter

from inside the white hole gets flung out.

Energy or matter outside the event horizon

can never enter the white hole.

It just can't.

There's this outward-flowing barrier of water