Original subtitles

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 clues that can unlock the secrets of white

holes.

Can unexplained energy bursts in deep space be a sign of these enigmatic

objects?

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

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 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 pulls 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 spacetime, the fabric

of the cosmos, which is flexible.

Extremely heavy objects can actually warp spacetime 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 physicists' 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 it 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 join 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?

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 that's

preventing it from doing so.

Flipping the physics of black holes 180 degrees unlocks how a white hole should

work.

What would this look like in the depths of space?

A black hole's immense gravity draws in everything that gets too close.

As a planet approaches the dark sphere of the event horizon, it stretches out

and disintegrates.

Once inside, it's a one-way trip towards the black hole's infinitely dense heart.

A white hole works in the opposite way.

Energy and matter accelerate outwards from its center.

Once outside the event horizon, nothing can return.

The science of white holes works.

But finding one in space is a big challenge.

The problem with white holes is the equations allow for a lot of different

conditions for these things. And so we can look all over the sky, but we don't

really know what we're looking for.

How could mysterious bursts of energy lead astronomers to the first ever

sighting of a white hole?

Why could the weird world of quantum physics unlock the Genesis?

of these mysterious objects.

Astronomers are on the hunt for the most elusive object in the cosmos.

The white hole.

Einstein's theory of general relativity predicts that they can exist.

Reverse engineering their twin, the black hole, reveals how white holes

should work.

But so far, white holes have eluded detection.

If white holes exist, they might last a long time or a short time. They might

give off one kind of light versus another kind of light. All of these

things, all of these variables make them very hard to search for.

Where might white holes be hiding in the universe?

What are the signs that will help us find them?

Astronomers believe that tracing the energy a white hole shoots out into

space could pinpoint its position.

And it's possible that we might have already seen one.

In June 2006, the Swift Space Telescope detects a massive release of energy.

in a distant galaxy around 2 billion light years away.

It's a super-intense beam of radiation called a gamma-ray burst.

Gamma-ray bursts are some of the most extreme and luminous events in the

universe. We think that they happen when massive stars explode or when two hyper

-dense neutron stars collide.

They are hyper energetic over a very short period of time and that means that

they're so-called luminosity where the amount of energy that these events

liberate in a certain interval of time is extraordinarily high

The gamma-ray burst that Swift sees

lasts over a hundred seconds a Burst this long likely comes

from gamma rays released by a star going supernova.

NASA tasks the Hubble Space Telescope to search for the aftermath of this

probable stellar explosion.

Hubble spends weeks hunting for the telltale glow of light that a supernova

always produces after the initial gamma ray burst.

But Hubble finds no such glow.

When we followed up and looked at this galaxy, there wasn't anything there.

There was no supernova associated with it.

It's as if the gamma ray burst appeared from nowhere.

To this day, no one knows for sure what created it.

But one object could, in theory, be able to blast into existence.

Release a vast amount of energy.

and then simply vanish.

An explosion of light appears from seemingly nothing.

Twin beams of intense gamma radiation traveling at almost the speed of light

shoot out across space.

The gamma ray burst.

Turning down the brightness on this cosmic light show reveals the possible

source of the fireworks.

A perfectly spherical ball spewing out so much energy that nothing can enter

it, not even light, a white hole.

The Swift Space Telescope spots a number of similar unexplained blasts over the

next 15 years.

Are these the signs that astronomers searching for white holes are looking

for?

Since 2006, there have been several gamma ray bursts that aren't really well

explained by the standard models out there. Perhaps they could be the long

-sought white holes.

A single gamma ray burst releases more energy in 10 seconds than our sun will

emit in 10 billion years.

If this mysterious gamma ray burst is from a white hole, where does this

energy come from?

And how does it get inside the white hole in the first place?

The solution to this puzzle may lie inside the super-dense heart of the

white hole's twin, the black hole.

Black holes are so dense and warp space so much they work like cosmic car

crushers Matter falling in first gets stretched Then so

extremely compressed it almost ceases to exist

Einstein's theories predict

that inside a black hole Matter squashes to an infinitely hot, small, and

dense point.

But the problem with infinity is that what works in theory may not work in

practice.

It's one thing to mathematically express infinity.

It's another thing to realize infinity in our actual universe. And there has

been no observations of an actual infinite density of anything.

To me, whenever you have infinity in something, it's kind of the equivalent

of before explorers knew what was on the Earth and they said, there be dragons.

It means that we just don't know what goes on there.

I personally don't believe in infinity. I think that's just where we reach the

limit of our knowledge, the limit of our physics.

Physicists are now evolving Einstein's theories to explore what really happens

inside a black hole.

these new ideas put a limit on how small and how dense the heart of a black hole

can get and That limit could unlock where the energy pouring out

from a white hole comes from Well, the idea now is that there is a smallest

amount of volume in space.

You cannot get any less than that It's not zero very tiny, but it's not zero

That's like a brick wall. When that black hole collapses down and hits that

volume, it basically has to stop.

One radical theory explains what that brick wall is and

what it is made from.

Inside the nucleus of every atom are two types of particles, protons and

neutrons.

Inside these subatomic particles are even smaller entities called quarks.

Some scientists believe if we could peer deeper, we would find the fundamental

building blocks of both matter and space.

Tiny quantum loops.

These are the threads that weave together the fabric of the universe.

These quantum loops are the building blocks of more than just matter and

energy.

They make up space itself.

The theory says that it is impossible to compress anything below the size of the

loops.

That means the loops put a limit on how dense a black hole's heart can get.

This idea could unlock the mystery of where the energy lasting out from a

white hole comes from when the matter and energy a black hole eats

can be compressed no further the quantum loops throw everything

into reverse there's a bounce to the material that enters a black hole event

horizon. That eventually, everything that the black hole has eaten or

consumed during its lifetime must inevitably find some way out again.

It's likely that there is no infinitely small point at the center of a black

hole.

Instead, there could be a ball of super dense matter.

It contains everything that the black hole has swallowed in its lifetime.

Eventually, this ball reaches a point where it can contract no further.

And so it goes into reverse.

It releases matter and energy, swallowing up its event horizon.

What was once a black hole now looks a lot like a white hole.

The theory of quantum loops unlocks where the energy blasting from a white

hole comes from and how it got inside in the first place.

It states that a white hole is one stage in the evolution of a black hole.

If everything in this theory adds up, then what this means is a collapsing and

bouncing black hole could be a path to a white hole.

It is possible that bouncing black holes unleash the mysterious gamma ray bursts

that the Swift Space Telescope detects.

But what type of black hole could we actually see live as it transforms into

a white hole?

And where in the sky should astronomers point their telescopes to capture the

moment of eruption?

astronomers are on the hunt for elusive white holes.

One theory states that they release vast amounts of energy when a quirk of

quantum physics throws black holes into reverse.

This change is called a bounce.

No astronomer has ever seen this dramatic transformation.

Where should we point our telescopes to witness it live?

If we're going to look for black holes that are becoming white holes, then we

have to look in the right places and for the right things.

Space is big. It's huge.

So this is very important if we're going to find these things.

Most of the black holes in our galaxy are stellar black holes.

Each one weighs around 10 times more than our Sun.

A stellar black hole forms when a star dies.

It leaves behind its super-dense core after it goes supernova.

This core collapses under its own extreme gravity.

This gravity well is so large that it eventually turns into a black hole.

Our Milky Way contains around 100 million stellar black holes.

In theory, seeing one bounce into a white hole is just a matter of time.

If there's this idea that black holes do eventually come to the end of their

lives and turn into white holes, couldn't we just wait for that to

happen? There are black holes all around us.

But there's a problem waiting for stellar black holes to turn into white

holes The transformation could take so long

that it will probably never happen We as flesh-and-blood human beings on our

tiny little planet Earth think of time as some constant force, but it's

actually not One of the fundamental tenets of general and special relativity

is that time and space are fundamentally the same thing. And because black holes

warp the fabric of space-time so much, they do really crazy things with time.

So in a way, observing anything close to a black hole is like watching time in

really, really slow motion.

And so a black hole could, in principle, take trillions of years to evolve in any

real way.

The Milky Way is around 13.6 billion years old.

The rules of relativity mean that the stellar black holes in our galaxy are

too large and too young to bounce into white holes.

The telescopes on Earth could watch the black holes in the Milky Way for

billions of years and never see one collapse into a white hole.

When we think of a black hole and we think of one that's like ten times the

mass of the Sun a sort of a typical Stellar mass black hole that takes far

longer than the age of the universe for this thing to rebound Astronomers think

that a black hole has to be very small and very old to even stand a chance of

bouncing into a white hole Where in the cosmos can they find them

A clue could lie in the images taken by space telescopes that study some of the

oldest objects in the universe.

For 17 years, NASA's Spitzer Space Telescope gazes into the farthest

reaches of space.

It literally looks back through time, thanks to its special infrared camera.

The further away from Earth an object is in space, the older the light our

telescopes receive.

If we could detect the light from objects billions of light-years away,

we'd see billions of years into the past.

But objects are also moving away from Earth as the universe expands.

stretching their light into the infrared.

Spitzer's camera is tuned to infrared to spot things in the universe few

other telescopes can see.

The amazing thing is it can see things in the universe that are completely off

limits to any other sort of light.

With the Spitzer Space Telescope, you can see events very close to the

beginning of time.

Spitzer takes this image of a portion of the universe.

It shows a one degree wide strip of the sky in the Great Bear constellation.

This tiny sliver of space contains 50,000 visible galaxies.

The image offers a possible glimpse of objects that could bounce into white

holes.

To see extremely far back in time, astronomers must first remove all the

bright points of light that come from closer stars and galaxies.

The technique leaves behind this, a background infrared glow coming from the

ancient cosmos.

The glow comes from something very old and very distant.

What is emitting this huge amount of infrared energy?

Another space telescope could unlock the mystery.

The Chandra telescope sees the universe in X-rays.

X-rays sit at the opposite end of the light spectrum to infrared.

They reveal the hidden light coming from super-violent events like supernovae.

Astronomers direct Chandra's X-ray camera to the exact same patch of sky as

Spitzer.

It shows that the ancient universe also has an uneven X-ray glow.

Astronomers use computers to compare the two images from the two telescopes.

They make an extraordinary discovery.

One fifth of the bright patches of infrared light match up with bright

patches of X-rays.

Way, way down, deep in the noise, you need a computer to pull out the

statistics. There's a correlation between this background glow in the X

-rays and infrared, and that's very mysterious.

No object should be able to glow in both those types of light brightly at once.

Astronomers believe that there is one object in the early universe that could

glow in this way.

Remember, we're looking eons back in time here at some of the earliest

moments of our universe.

And we're seeing objects that are emitting a huge amount of energy across

the electromagnetic spectrum.

And what's the kind of object that could do that?

It's a black hole.

The telescopes see back in time to before stars were even born.

How is it possible for black holes to exist?

if there were no dying stars to make them.

We know that black holes take an unimaginable amount of gravitational

power to make, and the only way we know how to make that is an exploding star,

the core being compressed to unimaginable densities.

But is it possible the universe had another way to make black holes,

something that had nothing to do with stars, something that only existed in

conditions just after the Big Bang?

The Big Bang unleashes forces so powerful they could, in theory, bend

space and time enough to make small black holes.

Milliseconds after the Big Bang, the universe is a tangled web of pure

energy.

Super-dense pools of this energy condense and collapse under their own

gravity. to rip deep wells in space-time.

These primordial black holes are born small.

They mature and shrink further over billions of years.

In theory, many could now be old enough and dense enough to bounce into white

holes.

Just in time for us to spot them.

So this type of black hole is really, really small.

And because it's so small, we might be in this sort of Goldilocks zone in our

history of the universe, in which just enough time has passed for us actually

to be observing this transformation now.

A tiny primordial black hole could be astronomers' ticket to witnessing the

birth of a white hole.

But is there something even weirder out there waiting to be discovered?

Could white holes be the missing ingredient of theoretical tunnels

through time and space?

And how could white holes make it possible to travel to the other side of

the universe?

White holes are cosmic oddballs born from Einstein's theory of relativity.

One idea is that a white hole is the last gasp of a dying black hole.

A burst of energy released in one giant cosmic belch.

But Einstein's theory also makes an even more mind blowing link between black and

white holes.

A tunnel to a different place and time.

known as a wormhole.

What Einstein showed us when he invented general relativity is that space is not

just this background against which everything takes place.

Space is a part of the game. It expands, it contracts, it warps, it waves, and

it can actually have tunnels.

A wormhole might sound like science fiction, but in theory,

A shortcut through space and time isn't a great leap in the upside-down world of

white and black holes.

Matter and light cross the event horizon of a black hole.

The extreme gravity inside the black hole stretches space into a funnel.

It is theoretically possible for something that survives the crushing

gravity to pass through a wormhole.

and emerge from a white hole in a different part of the universe.

You have a black hole on one side and a white hole on the other. Now it sounds

crazy because you can enter a black hole at some place or time and exit the white

hole at another place and time.

But Einstein's theory states that a wormhole only works as a closed system.

The problem is when you look at the mathematics of how a wormhole exists,

they're unstable.

If even a single atom of hydrogen enters one, they collapse.

A tunnel between a black hole and a white hole must be fed an exotic form of

matter to stay open.

Humans will need to generate this weird material to stop a traversable wormhole

from collapsing.

In order to make them stable, you'd have to have some sort of matter that

actually has a negative energy.

And I don't think we even really understand what that means.

So while Einstein's theories led to the idea that you could build these bridges,

how exactly they would stay open is still a complete mystery.

But when Einstein speaks, astronomers listen.

And they are rising to the incredible challenge of finding a tunnel between a

black and a white hole.

Their quest begins with the black hole astronomers believe lies at the heart of

our own galaxy, Sagittarius A-star.

Every year, the European Southern Observatory in Chile takes a photograph

of the same spot at the center of the Milky Way.

The data from 16 years of observations creates this four-second time lapse.

It shows stars 26,000 light years away from Earth, circling the heart of our

galaxy.

But what they orbit appears completely invisible.

You can see these stars, and they're moving around nothing.

You look to the center, where these stars are orbiting around, and there's

nothing there.

There has to be mass there because it's telling these stars how to move in this

really, really well-defined orbit, but there's nothing there.

Astronomers believe that only a giant black hole has enough mass for stars to

orbit in this way.

One theory states that charting the orbit of one of these stars could reveal

the presence of a wormhole.

S2 is the closest star to the likely location of the black hole Sagittarius A

star.

The idea is to identify all the different influences on S2's orbit

to see if something unknown affects the way the star moves through space.

Astronomers think that the main influence on S2's orbit is the huge

gravity of Sagittarius A star.

But S2 moves in a very crowded corner of space where other stars and

black holes could affect its motion.

Astronomers are studying the effects of all these objects to calculate the path

of S2 with extreme accuracy.

They're looking for a tiny deviation that they can't explain which could be

gravity leaking through a wormhole The

theory sounds fantastical but physics supports it as a potential way to

identify the presence of a wormhole Collisions between massive objects

like neutron stars and black holes

generate gravitational disturbances.

These huge distortions in space-time are the one thing that could potentially

pass into white holes.

In theory, a disturbance from a violent event at the other end of the universe

might enter a nearby black or white hole,

travel through a wormhole,

and emerge from Sagittarius A star.

This disturbance from an unknown time and place could then alter the orbit of

the star S2.

What if we get better and better observations over time and look very

carefully at the way the star is accelerating?

We might be able to just tease tiny little clues out of the orbit that

there's something else in there, some more gravitational exotic things,

perhaps even a wormhole.

Future telescopes will be able to track S2's movements with greater precision.

If they do spot something unusual,

Einstein's incredible wormhole theory could be proven correct.

If we find out that wormholes actually do exist and there is one in our stellar

neighborhood, then this opens up a whole new realm of research.

This tells us that we can now understand space and time in ways that we never

could have before.

So even though humans may not be able to go at any time in the near future, we

could start along the path and send probes to see what happens.

White holes are one of the weirdest ideas in the universe.

They could be responsible for unexplained blasts of radiation that

shoot across our galaxy.

It's possible that they are born at the moment super-ancient black holes die.

What started as an idea triggered by the mind of the world's most famous

physicist could really exist.

If Einstein turned out to be right about white holes, man, I would just say,

there he is again. He did it again, Albert Einstein, right? My hero.

In the future, we could discover a real white hole that is a portal to a

different time and space.

All of a sudden, access not only all the space of the universe, but the entire

history and future of the universe as well. And from there, your imagination

can take you pretty much anywhere.

New telescopes promise to unlock the mysteries of these cosmic wonders.

White holes could exist.

And they could be out there, just waiting to be discovered.