Original subtitles

You might have seen a boxing match on TV.

Maybe you've even seen one live. But you have never seen

a contest like this.

Take your ringside seat to the fight of the cosmos.

This is gonna be a wonderful fight to witness,

but you ought to be a few million, billion light years away.

It's like being punched by the ghost of Muhammad Ali.

You don't even see it coming.

Our fighters don't float like a butterfly or sting like a bee.

But they can deliver the ultimate knockout blow.

It is a soul-chilling,

mind-crushing amount of energy. It's just unbelievable.

It's a fight between two supermassive black holes.

Forget about the World Heavyweight Championships,

this is the universe's heavyweight championships.

Get ready for the heavyweight championship of the universe.

2021. Scientists detect

a gigantic rumble deep in space.

A tsunami of gravitational waves.

Giant ripples racing across the universe.

Gravitational waves that big have to come from

a giant, cataclysmic event.

The universe is immense

and full of very violent events

that are happening every single day.

The universe is a scary place.

There is violence everywhere we look.

The growls and roars are clues

about the ultimate cosmic brawl.

The most violent event in the universe.

But we don't know where they're coming from.

Imagine a storm is coming in the middle of the night.

You can't see the storm, you can't see the lightning,

but you can hear that rumble of the distant thunder

and you know that it's coming.

This distant rumble of gravitational waves

is like the footwork of heavyweights

pounding the canvas of the boxing ring.

The waves are caused by something massive

throwing its weight around.

It's not the first time we've detected gravitational waves.

Our experiments have picked up the signal

of two small stellar mass black holes colliding.

These waves are high-pitched

and ring like a boxing bell.

The deep space growl is a much lower frequency.

Like the roar of a crowd.

The difference in frequencies would be even more exaggerated

than the difference between a sparrow chirping

and the sound coming from a blue whale underwater.

It would be orders of magnitude more different than that.

The low frequency of the deep-space rumble

tells us that the waves are colossal.

Imagine throwing a stone in the water

and watching the little ripples come out.

Now imagine throwing in a boulder a billion times more massive

and watching the huge waves that come from that.

Those are the waves that we're looking at.

These are more difficult to detect

because the waves are so big.

One of their wavelengths is about 15 light years.

You could wait for 15 years

and only have one wavelength go by the Earth.

The waves are too big for an Earth-bound detector to pick up.

So, to search for the source of these giant waves

Chiara Mingarelli and her team

use a detector already in space.

Something large enough to pick up these galactic heavyweights.

Spinning dead stars called pulsars.

Our galaxy is awash with pulsars.

Now they're called pulsars because they pulsate very regularly.

They're like cosmic lighthouses.

The lighthouse beams are so regular you can set your watch by them.

But when a huge gravitational wave hits them,

the timing gets knocked out of whack.

That pulsar's gonna basically rock back and forth,

and that's going to change the timing of the pulses

that we measure from that object.

To identify the source of the gravitational waves,

Chiara and her team measure the wobbles

of 100 pulsars spread across light years of space.

It's like a tsunami.

And the pulsars are like the buoys on the surface of the ocean.

And as the tsunami passes by,

we can watch all of them moving and shifting up and down.

So our pulsar timing array

is a gravitational wave warning system.

The pulsar array has identified the source of the tsunami

of gravitational waves.

The only thing we know of that can makes these very long wavelength,

very low-pitch gravitational waves

would be the collisions of supermassive black holes.

They're massive. They're huge.

And they know how to throw their weight around.

Supermassive black hole binaries

produce the loudest gravitational waves in the universe.

The gravitational waves' signal

revealed something extraordinary.

It's not just gravitational waves

coming from one black hole binary pair,

it's actually from the cosmic population

of supermassive black hole binaries.

Chiara and her team think there may be tens of thousands

of heavyweight bouts going on.

Now, the scientists want to pick out the sound

of one single collision

between two supermassive black holes

from the background roar.

If we were to hear a supermassive black hole merger,

it would wound like a very low-frequency growl,

this... whoooooooo

that would last about 25 million years.

To date, we haven't witnessed two supermassive black holes

trading blows in real time.

But we have seen events leading up to the championship bout.

We've watched galaxies merge. We've seen stars explode.

We've seen so many violent events in the universe.

But we haven't seen this one.

It's odd if you think about it.

We haven't seen the biggest one.

We haven't seen mergers between supermassive black holes.

But that may be about to change.

Chiara predicts there are 112 fighters

who are pumped up and ready to enter the ring.

In the next five years, we should be able to detect

at least one supermassive black hole merger.

It'll be the most violent event in the cosmos.

Let's put that in context.

We talk about how supernova are some of the most

explosive, energetic things in our universe.

Well, colliding supermassive black holes

are a billion billion billion billion times more energetic

than a supernova.

Think about all of the light

being emitted by everything in the universe,

every star, every galaxy.

In one instant, two supermassive black holes colliding

could release 100 million times that energy.

Imagine being punched in the face

by the biggest, baddest heavyweight of all time.

Ouch. This is way bigger than that.

Where does all this energy come from?

Surprisingly, it originates

in the smallest atoms in the cosmos

in a story that dates back billions of years,

all the way to the birth of the universe.

2020. The earthbound gravitational wave detector, LIGO,

picks up the distinctive signal

of a stellar mass black hole merger.

What we saw was a black hole

of 85 times the mass of our sun

and another black hole of 66 times the mass of our sun

smashing together to create a combined black hole.

As someone who studies black hole mergers,

this was a really exciting event.

We're talking about the largest, the heaviest,

the most massive black holes we have seen collide to date.

It may be the largest detection, but on a universal scale

it's still a small fry.

Like lightweight boxers, the two black holes circle each other

and emit low-energy gravitational waves.

This energy loss causes the black holes

to spiral in together.

Finally, they collide in a cosmos-shattering event...

...forming a single black hole

and releasing a huge blast of gravitational waves.

But when astronomers examine the single merged black hole,

something doesn't add up.

If you take the combined mass of the two black holes,

you get to 150 times the mass of our sun.

But actually, the black hole that's left

only has a mass of 142 times the mass of our sun.

So the mass you have before the event

does not equal the mass you have after the event.

What happened to that missing eight solar masses?

The way these black hole mergers work

is very roughly five percent of the total mass of the system

gets converted into energy.

It all comes down to E=mc2.

This is that beautiful equation that Einstein told us, E=mc2.

E is the energy, and M is the mass.

Einstein taught us that mass and energy are related.

In fact, much of what we call mass is actually energy.

In this case, the violence of the collision

transforms 18,000 trillion trillion tons of matter

into an explosion of gravitational waves.

In just a fraction of a second,

eight suns-worth of matter

is converted into pure, unadulterated energy.

The amount of energy released was so great

that if you add up all the energy of all the stars

burning in the universe, it was bigger than that.

This event was a collision between relative lightweights.

Two stellar mass black holes.

To understand heavyweight bouts, we need to scale up

to supermassive black holes.

In the universe of sports,

supermassive black holes are the heavyweight contenders.

With these big black holes, size matters. The bigger the better.

More mass means more energy, which means more destructive power.

We don't need to look too far to find this devastating muscle.

This is M87 star,

one of the largest supermassive black holes

in our cosmic zip code.

M87 star is huge.

It weighs about six billion solar masses,

about six billion suns, and it's the size of our solar system.

A collision between two six billion solar mass supermassive black holes

would release around five times ten to the power of 56 joules.

So, what does that mean in real-world terms?

It's hard to use words

to express how much energy this is

and the numbers are so huge, they're almost meaningless.

The only way I can really explain this is... argh!

In physics, we have these comparisons

so we can get a mental picture,

but for something like this there is no mental picture.

That is so big!

So where does this destructive mass and energy come from?

It starts with the simplest ingredient, hydrogen.

Hydrogen is the basic building block of the universe.

Each atom is tiny, but it contains a lot of energy.

Hydrogen atoms contain a huge amount of energy,

just like all matter does.

And if it's unlocked in a certain way,

there can be huge explosions.

You take the mass contained simply in my hand

and you could blow up pretty much the entire Earth.

Matter has energy because it formed from energy

in the early moments of the universe.

In many ways, atoms are reservoirs

of stored energy from the big bang.

13.8 billion years ago,

the universe ignites

in a super-hot ball of intense energy.

Right after the big bang, there's a tremendous amount of energy.

So much energy, in fact, that normal atoms can't exist.

As that early energy starts to cool,

it can start to form primitive matter.

The universe takes that first matter and energy

in the form of hydrogen atoms

and starts the process of creating a supermassive black hole.

Step one, build giant stars.

So, gravity brings together

gas, dust, hydrogen, all of that stuff,

and as the clouds become more dense,

they attract even more material.

As they spin, they get hotter and hotter.

And as that temperature and pressure increase,

finally it ignites nuclear fusion within the core

and creates an actual star.

These huge stars are like cosmic rock stars.

They live fast and die young.

When they die, they flame out in a huge explosion.

A supernova.

The entire star turns itself inside out

and releases a shockwave,

going a good fraction of the speed of light,

and releases enough energy to just obliterate you.

If the dying star is more than 15 stellar masses,

its core collapses into a black hole.

It's kind of astounding what the universe is doing.

It's taking incredibly simple things like hydrogen atoms and using gravity

to ultimately bring all this stuff together

and make things like black holes.

I find it quite beautiful how our whole cosmic history

is the story of

little things coming together into bigger things.

But these stellar mass black holes are tiny flyweights.

To step up to the heavyweight division,

they have to grow billions of times more massive.

But how?

How do black holes become supermassive?

This is the age-old question. We're not really sure.

The current stated understanding

of how black holes become supermassive is like... uh,

we're confused, we really don't know.

In June of 2018,

we spotted a clue.

An enormous flash of light.

AT2018cow,

nicknamed "The Cow",

was the brightest explosion ever recorded.

A huge amount of energy was released

and then, all of a sudden, everything was gone.

This explosion was incredibly violent.

At first, it was thought to just be a supernova, a flash of light.

But over time, it became clear that this was something

much more powerful.

It was too bright, basically, to be a supernova.

It was extremely bright and it didn't fit into

any of our theoretical understandings

of how bright supernovas should be.

One explanation is that the light may have come from

a black hole feeding on a small, white dwarf star,

weighing less than the Sun.

What really seemed to fit that model

was a star getting too close to a black hole

and getting ripped apart,

and then everything going right down the black hole.

A black hole gains mass every time it eats something.

That's how they grow. Whether it's a gas cloud or a star

or another black hole,

once it gains that mass it's gained that mass.

People often ask me, What happens to the mass

that falls into a black hole? Does it go to another dimension?

And the answer is no.

It's still there. It's inside the black hole.

They get bigger. They grow.

Could this be how weak, flyweight black holes

turn into mean and powerful supermassive heavyweights?

The star is like protein,

and the black hole is like a boxer.

And so, the more protein they get, the more stars they consume,

the stronger they get, the more destructive they can be.

But there's a problem with the training program explanation.

Eating small stars one at a time

just doesn't add enough mass fast enough

to grow the supermassive black holes that we see today.

That's like boxers eating just one egg per day.

Like them, black holes need much bigger meals.

And in 2020, we detected one.

A sudden burst of gravitational waves

from a black hole gorging on the remains

of a dead star...

...called a neutron star.

For scientists, January 2020 was exciting

because it was the first time LIGO observed

the very first black hole neutron star merger.

Neutron stars may be small

but they are inconceivably dense.

You want to talk about an enormous mass, talk about a neutron star.

That's one heck of a snack.

The black hole swallowed the neutron star in one gulp.

So, this black hole ate a whole neutron star,

which means it gained just over ten percent of its entire body weight

in one shot.

Ten percent doesn't sound like a lot,

but then we detected another black hole

swallowing a neutron star just ten days later,

suggesting that there are lots of black holes

bulking up across the universe.

But even with this extreme weight gain,

it's probably not enough to get supermassive.

They need to eat even more.

If you're a black hole and you want to get bigger,

your best bet is to merge with another black hole.

But there's a catch.

So, if you're a flyweight black hole,

and you try to eat

all of the other flyweight black holes,

there's just not enough time in the history of the universe

for you to become a supermassive black hole.

But you can make it to middleweight.

So, exactly how supermassive black holes grow so large

remains an open question.

We do know that the process started in the very early universe

with a journey from the lightest element

to the most intimidating object in the cosmos.

It's so interesting how the cosmos can take something

as simple as a hydrogen atom

and build stellar-mass black holes

and intermediate-mass black holes

and even supermassive black holes

out of these really densely compressed hydrogen atoms.

It's really a wonder.

Now, 13.8 billion years after the big bang,

supermassive black holes feed and flex their muscles

ready to fight for the heavyweight championship of the universe.

These supermassive black holes

have been bulking up since the age of the universe.

These black holes have been getting ready for the fight.

They have been bulking up, they have been eating entire stars

as snacks, to get the mass they need.

So they are ready to rumble.

It's not The Rumble in the Jungle.

This is the battle to be the boss of the cosmos.

Supermassive black hole versus supermassive black hole.

Fought in the grandest arena.

The fighters' entourage, their host galaxies,

escort them to the ring.

But even this journey is violent, triggering starbursts,

jets, and carnage.

Things are about to get nasty.

Galaxies can look calm and serene,

but they can get into pretty big scraps.

There's a lot of them that are totally messed up,

and are clearly merging with each other.

Eventually, even our own galaxy will merge with another galaxy.

In a few billion years,

a timescale that I'm not too worried about myself,

the Milky Way and the Andromeda Galaxy will collide.

The Milky Way and Andromeda each have supermassive black holes.

And when they collide,

their supermassive black holes will collide too.

This is an incredibly dangerous event for our solar system.

Our solar system could be swept out

to be somewhere else in this newly-formed galaxy,

or it could be completely ejected from the galaxy.

If there's any life around near the merger

of these supermassive black holes, it would be obliterated.

When galaxies fight, their gravity pulls on each other,

twisting and distorting their structures.

The galaxy will be warped and morphed into

different ways that we can only imagine

how twisted it would be.

This violent cosmic tango

brings the two supermassive black holes together.

It's elegant. It's beautiful. It's this billion-year

choreographed dance that is entirely conducted by gravity.

The two heavyweight fighters approach each other.

Their feet beat out a rhythm on the canvas,

just like circling black holes

release low-energy gravitational waves.

You have these giant beasts

that are stalking around each other

and as they do, they create these gravitational waves.

June, 2021.

Astronomers photograph a galactic collision

and witness a spectacular pre-fight fireworks show.

One of the amazing things that can happen when galaxies collide is

they can create tremendous starbursts.

There is a big in-rush as all of that gas follows that gravity.

As the gas gets hotter and denser, it creates shockwaves.

And each shockwave actually creates a new generation of stars

going out around the core of the galaxy.

The sudden starburst lights up the merging galaxies.

The in-rushing gas also fuels the prize-fighters,

the supermassive black holes

spiraling towards the merging galactic center.

But only if the galaxies approach at the right angle.

It's not the case that every merger feeds a black hole.

Sometimes it actually strips material

away from the central regions

and then there's no food there for the black holes to eat.

A head-on collision with another black hole

could strip the material around the supermassive black hole.

With nothing there,

the black holes can't power themselves.

To get the biggest bang requires an attacking angle

that'll help feed a starving black hole.

With a grazing collision,

the gas pockets surrounding the black hole survive

and gain more mass.

And that can power it even more.

It can make it even more spectacular.

If there's a big supermassive black hole,

that suddenly finds it surrounded by loads of gas

and other material it can eat,

it goes on a kind of feeding frenzy.

If you're a hungry supermassive black hole,

then this is your lunchtime buffet.

Not all the gas falls into the supermassive black hole.

Other parts of the matter actually gets caught up in what we call

an "accretion disk" rotating around the outside of the black hole.

This bright vortex spins around the supermassive black hole

at over two million miles an hour.

The material in the disk rubs against itself,

creating friction.

Friction generates heat. If I rub my hands together,

they get a little bit warm.

If I rub my hands together

at hundreds of thousands of miles per hour,

it's gonna get very, very, very warm.

The accretion disk keeps up blasting out intense light.

In 2020, NASA's Hubble Space Telescope

saw two fueled-up supermassive black holes

lighting up for the fight.

We call them quasars.

Quasars are a sub-class of very bright black holes

that are emitting huge amounts of power.

So these can be seen at the far reaches of the universe.

Black holes, these so-called dark things,

when they're growing at a very high rate,

are some of the brightest lights in the universe.

To date, we've detected over 100 pairs of quasars

in the cores of merging galaxies.

We think they will all eventually collide.

But before they do, they'll put on

a spectacular and lethal light show...

A common theme in science fiction

are different kinds of jets of energy or beams

that people shoot out of their eyes or their hands.

Well, supermassive black holes do that, too.

...firing out relativistic jets.

When those jets fire up,

that's when you're talking about superstar.

Really, really bright lights.

And at this point, the galaxy is lit up and ready to go.

These are the spotlights on Madison Square Garden.

This is telling you that the event is going down.

A single supermassive black hole jet

will produce more energy in a second

than the sun will produce in its entire ten-billion-year lifetime.

Imagine a laser of radiation

that is light years in length and across.

That's what we're talking about. This thing would fry a planet.

This is no pre-fight hype.

In February, 2020 we saw the impact of a jet.

So in the Ophiuchus galaxy cluster,

there's an enormous void

that is 15 times wider than the Milky Way galaxy.

And this has all been sculpted, carved

by jets from a supermassive black hole.

It's like this scar on the universe.

It's a million light years across. It's huge.

Scientists calculate the impact of the jet hitting the cluster

was equivalent to a 20 billion billion megaton TNT explosion

every thousandth of a second

for 240 million years.

But how does a black hole generate so much power?

Even though there's a lot of energy

in the accretion disk surrounding a black hole,

there's not enough to launch these really powerful jets.

Because we can't account for it any other way,

there must be something else

that's contributing energy to these jets.

We get a clue in 2021

when scientists publish a new photo

of the supermassive black hole M87 star.

It shows the accretion disk.

The lines represent magnetic field lines.

The fast-spinning accretion disk drags the magnetic field

around the supermassive black hole,

charging it up for the battle.

The accretion disk around a black hole

isn't just swirling around like crazy.

It's also undulating and moving and wiggling,

and this causes the magnetic field to fold in on itself.

And every time it folds, it amplifies itself,

getting stronger and stronger and stronger.

This is a dynamo that powers this incredible magnetic field.

The magnetic field can't hold onto the building energy any longer.

It erupts.

These magnetic field lines then sweep up and away

like a tornado. And that can lift material

away from the black hole and the accretion disk

and shoot it out into intergalactic space.

The relativistic jet's immense power

may be a showstopper, but when it's time to land the killer punch

supermassive black holes

draw on an even more powerful force, gravity.

Jets are very powerful, but really only on a relatively small scale.

When you're talking about cosmic scale,

gravity always wins.

Nothing is as powerful as gravity.

Across the universe, supermassive black holes duke it out

in the cosmos' version of heavyweight superfights.

Supermassive black holes are merging around us all the time.

It's only our ability to detect them

that's preventing us from seeing them.

Scientists have identified at least a dozen pairs

of supermassive black holes circling each other.

We have some hints of some galaxies

where we think it might happen,

where we see two glowing black holes that are getting very close.

But not all these matches will end with a knockout.

Black hole collisions happen all the time,

but they don't always go according to plan.

When black holes come together, really strange things can happen.

The Hubble Space Telescope spots something strange

in a distant galaxy called 3C186.

It's a quasar, an active supermassive black hole.

But it's in the wrong place.

In nearly every galaxy, we see

the supermassive black hole sits right at the center.

That makes sense.

Because that's the only place with enough material to power them.

But in 3C186, that's not what we see.

The supermassive black hole is displaced from the center.

And not a little bit. It's 35,000 light years.

So to see a quasar 35,000 light years away from the core

means something really violent had to happen there.

The quasar is racing away from the center of the galaxy

at over four million miles an hour.

That is insane!

The magnitude of the energy and the forces required

are just something unimaginable.

So what can kick

a giant black hole out of a galaxy?

What has that kind of power?

The answer is a clash that wasn't evenly matched.

The two supermassive black holes were different sizes,

a middleweight boxer taking on a heavyweight.

When humans set up a fight, we like to make it fair

because it's sport. Nature doesn't care about sport.

It's survival of the fittest.

This is not a fair fight. It's over before it even begins.

One punch and it's a K-O.

As these two black holes are merging,

there's one really small black hole

and one much bigger black hole.

The whole system wobbles around

and it can get more of a gravitational wave kick

in one direction than the other.

And that's momentum. That's a push. That's enough energy

to kick the black hole out.

The lopsided gravitational punch

sends the merged supermassive black hole

on a one-way trip to oblivion.

This tells us that gravitational waves can be

tremendously powerful. They can move a supermassive black hole

out from the center of a galaxy and send it on its way.

But it just carries on drifting. There's no way to stop it.

And who knows? In a few million years,

it could just drift entirely out of its galaxy

and go floating off into deep space.

In some matches, the fighters don't even land a punch.

Scientists spot a supermassive black hole

named B3 1715+425.

This black hole is strange.

Stripped of all its stars,

it hurtles through empty space at 4.5 million miles an hour.

The first thing that draws our attention

is this faint trail of debris across the sky.

There is actually a trail leading back to the center of the galaxy.

It's kinda like a dump truck that's filled with dirt

driving down the highway, and the dirt's flying off behind it.

This is a naked black hole.

The exposed supermassive black hole has lost its stars and galaxy.

A champion stripped of its fans and entourage.

So what event is powerful enough

to strip a supermassive black hole of its entire host galaxy?

That has to be something really big.

B3 is a smallish galaxy

and it got into a scrap with a much bigger one.

The stronger gravity of the bigger galaxy

stripped the stars away from that black hole and shot it out.

Typically, in the universe when something's bigger and more massive,

it wins. So this is true for galaxies.

A big galaxy versus a little galaxy,

put your money on the big one.

But when two evenly-matched heavyweights enter the ring...

...it's time for the main event.

A clash of the titans.

I grew up watching boxing with my dad,

so I've always been a boxing fan.

And I love a great battle. And what's a bigger battle

than a head-on collision between two supermassive black holes?

If you're a boxing fan, this is the big one.

We are ready. We are on the edge of our seats.

We've got two supermassive black holes,

each one is in their corner, and they're getting ready

for the fight of the century.

I mean, they're just gonna go at it, like goosh, goosh.

I would watch that. I'd pay-per-view that.

It doesn't get any better than this. These are prize-fighters

at the top of their game, they're trained to a T,

they're beefed up, they are ready to rumble.

Welcome to the heavyweight championship of the universe.

Weighing in at eight billion solar masses,

we have The Galactic Destroyer,

M101 star.

And in the other corner, at a punishing 7.8 billion suns,

The Star Crusher, NSC 47 star.

They are pumped and ready to rumble.

So here it is. We're finally here.

The crowd is roaring.

The bell has rung and the fighters are approaching each other.

They are ready to go at it.

Let's have a clean fight, fellas. Touch hands

and go back to your corners.

Round One. The two heavyweights circle,

testing the other's defenses.

The black holes are gonna do what the boxers are gonna do.

They're gonna circle each other and they're gonna orbit each other

and they're gonna size each other up.

Once these two supermassive black holes are close enough,

they're gravity inexorably is gonna draw them together.

As the two supermassive black holes get closer,

they throw a few exploratory jabs...

...triggering bursts of gravitational waves

that warp everything in their path.

These enormous gravitational waves

are completely deforming the fabric of space time around them.

Not just a little bit, but a lot!

It's like feeling the fighters approach in the boxing ring

from the next town over.

Next, the supermassive black holes' gravity

throws in a couple of right hooks

straight into the accretion disks.

What could happen is that they start to form like

an angle grinder. You'll see sparks flying

as they try to merge and form a new, single accretion disk.

When those accretion disks collide,

the whole thing is gonna light up like the 4th of July.

Spiraling in at millions of miles an hour

the heavyweight fighters get close,

delivering punishing body blows.

The event horizons, the surface of the supermassive black holes,

are about to touch.

In their final moments, these two supermassive black holes

are orbiting each other at a significant fraction

of the speed of light,

and their event horizons will touch.

And they'll eventually merge into one new supermassive black hole.

You might think: don't they bump into each other

like bowling balls? No, they don't.

Because what we're calling the edge of the black hole

is actually not a thing. That's just the surface

around the black hole. Gravity is so strong, nothing can come out.

The two supermassive black holes finally merge,

releasing around five percent of the mass they've gathered

over billions of years in an enormous burst

of gravitational waves.

The amount of energy we're talking about...

There's nothing to compare it to. It's mind-crushing.

There's really almost no point in thinking about it.

It's just not something I think that I can wrap my head around.

Coming from where I come from,

you know, you don't show weakness.

So I'm not gonna say that the collision of two black holes

is more powerful than one of my punches,

but... it's close.

The gigantic and powerful gravitational waves

race out from the collision zone,

leaving a single merged black hole.

This supermassive black hole, after it merges,

permanently deforms the fabric of space time around it.

And this deformation travels out at the speed of light.

The surviving 95 percent of mass

from the two colliding supermassive black holes

is now locked in a single ultramassive black hole.

The undisputed super heavyweight champion of the universe.

At least for now.

It seems the universe is always upping the ante.

Could there be something even more violent we haven't discovered yet?

The universe keeps wanting to give us something more violent all the time.

Energy locked in hydrogen atoms

formed at the birth of the universe

is finally released in the violent collision

and builds an ultramassive black hole.

This is one of the most beautiful stories in our universe.

You have the most energetic collision,

the most amount of energy released, the most violent event

can trace its origins to the humble hydrogen atom.

There are things constantly being built up and then destroyed.

It's sort of the cycle of life in our universe

that evolves various exotic phenomenon

and makes them into something more beautiful and transformative.

Our universe has managed to create

both these fearsome weapons of mass destruction,

monster black holes,

and also conscious life

that can write poetry and ponder the meaning of it all.

So, we have our champion.

Matter compressed and then smashed together

by supermassive black holes

creates the most violent event in the universe.

I don't think there's a contest.

The supermassive black hole collisions

are the most energetic, just like mind-numbingly large

amounts of energy in these collisions.

A merger of two supermassive black holes

is at the absolute top end extreme of that

for all possible events in the entire universe.

A supermassive black hole merger

is the most violent thing that we can observe in the universe.

Subtitling by Iyuno