MIKE ROWE: We're on a journey to the heart
of the supermassive black hole, M87 star.
Our mission, to investigate one of the most mysterious places
in the universe.
SUTTER: M87 is a great target for us to visit,
because one, it's close, and two, it's active,
it's feeding.
ROWE: Supermassive black holes are
the engines that power the universe.
Supermassive black holes are a key factor in
the birth, life, and eventual death of galaxies.
ROWE: And the more we study them,
the more puzzling they become.
They're the master key
to most of the unsolved mysteries in physics.
The physics inside a supermassive black hole are
beyond weird.
ROWE: They are the final frontier of our understanding.
Your imagination can run wild.
Maybe it's even the source of other universes.
ROWE: There's only one way to find out,
to go where no one has gone before and journey to the heart
of M87 star.
[explosion blasts]
We speed across M87,
a gigantic galaxy 55 million light-years from Earth.
At its heart lies a supermassive black hole,
M87 star.
It is the first and only black hole
ever photographed.
We want to find out how M87 star grew so large,
what lies inside, and how it controls the galaxy.
5,000 light-years out from the supermassive black hole,
we get our first sign of the danger ahead.
We see giant holes carved out of the galaxy,
starless voids thousands of light-years wide.
SUTTER: As we approach, we can see
that wreckage littered around the vicinity.
It's like entering the lair of the dragon and seeing
the bones of all the explorers who came before you.
ROWE: What cataclysmic force tore these giant
cavities in the galactic gas clouds?
As we fly next to a brilliant shaft of energy
thousands of light-years from M87 star,
we get a clue.
It's a deadly stream of
radiation shooting out across the galaxy,
a jet.
This jet looks like a searchlight
or a beam from a lighthouse.
PLAIT: You're seeing this monumental thing.
It's screaming out of the black hole,
blasting out radiation.
When I first saw a photo of a jet, I was like, "Whoa!"
Am I like, misreading the scale
of this image? Because there was this
crazy Star Trek like beam just coming out.
ROWE: In 1918, American astronomer Heber Curtis
described the jets as a curious straight ray.
A century later, observatory images
reveal they pulsate with energy.
SUTTER: The images show knots and clumps in these jets.
They show that it's just not smooth and nice,
that there's been a history of violence inside this jet.
ROWE: This violent energy pushes
the knots along the beams.
The knots reveal the speed of the jets.
[train whistle blows]
It's like looking at a fast-moving train.
Rail cars of the same color blur into one continuous image.
But different-colored cars stand out against the others.
It's the same with the knots moving along the jets.
So we can figure out how fast the jets are
really moving by looking at knots of material coming out
from near the black hole.
ROWE: When astronomers measured the speed of two knots,
they got a big surprise.
One is moving at 2.4 times the speed of light,
and the other is moving over six times faster than light.
How could this possibly be?
As weird as the physics around a black hole is,
that's not actually happening, nor is it allowed to happen.
SUTTER: Nothing can actually go faster than the speed of light,
so obviously, we're missing something here.
ROWE: The knots may seem to break the speed of light,
but the universe is just playing with us.
It's really just a consequence of the fact that
a lot of this jet is pointed toward us,
pointed partially toward the observer on Earth.
That, in a sense, is a sort of optical illusion
that tricks you into thinking it's moving faster.
ROWE: It's a simple trick of the light,
a bit like the way a spoon in a glass of water looks bent
and distorted.
The impossibly fast speed of the jet
is just an illusion of perspective.
From our perspective, it looks like the whole
thing is moving towards us faster than light.
But really, it's just cruising along very, very fast.
The jets aren't actually breaking the laws of physics.
They're pushing up against it.
They're going at 99.999995% the speed of light.
Imagine the energies necessary
to accelerate this entire jet to that speed.
ROWE: So what could produce enough energy to blast jets
across the galaxy at close to the speed of light?
There is a clue far ahead.
The jets shoot out from
a tiny, brightly glowing object.
This is where things go nuts.
This is the center of the action.
This is where the real stuff happens.
ROWE: A ring of super hot gas
and dust whirls around the supermassive black hole.
It's called the accretion disk,
and it shines a billion times brighter than the sun.
If you had a ringside seat next to M87 star,
you would probably be fried very, very fast.
But if you were some, you know, magical being and could survive
anything, and if you had,
you know, million SPF sunscreen and really,
really great sunglasses, what you would see is this
enormously bright vortex of gas swirling this dark void.
ROWE: This bright vortex spins around
the supermassive black hole,
at over two million miles an hour.
PLAIT: So there's a tremendous amount of friction as
material moving slower and faster rubs against each other.
That's what's heating the disk up,
and that's what's causing it to glow.
ROWE: Scientists think that the intense energy of
the accretion disk is the source of the jets.
The hot, swirling gas
and dust produces powerful magnetic fields.
As the disk spins, it twists up the magnetic fields
at the poles of the black hole.
Energy builds.
Finally, the magnetic fields can't
contain the energy any longer.
They snap and blast the jets out into he galaxy.
Even many light-ears away on the ship,
we can see this violent release of energy.
It's like the universe's biggest fireworks display.
Two jets streaking out of
M87 star's poles,
one shooting away into the distance,
the other racing past our ship.
We're at a safe distance.
Other things are not.
So when these jets shoot outward from the supermassive
black hole, they don't shoot outward into nothing.
If a jet hits a gas cloud, it annihilates it.
It just punches a hole right through it.
It's like a train going down a snowy track, right?
The gas is like the snow
and the jets are like this freight train plowing across it.
ROWE: But here,
a freight train traveling at close to the speed of light,
smashing into clouds of gas,
lighting our way to M87 star
as we follow the trail of destruction.
There is evidence of similar destruction across the universe.
In the Cygnus A galaxy, supermassive black hole jets
have caused damage on a colossal scale.
TREMBLAY: In many ways, Cygnus A is like
a cosmic shooting gallery.
You see this crime scene, this beautiful mess.
OLUSEYI: So when this jet comes out of the nucleus of Cygnus A,
it's gonna encounter gas clouds.
At that point, shockwaves set up, and this jet just rips
right through this material,
sending shock waves in every direction,
creating absolute chaos.
It's hard to believe how much devastation these jets
can cause... they're punching
a hole in the gas 100,000 light-years wide.
I mean, that's... that's the scale of an entire galaxy.
ROWE: As we head towards the center of
the M87 galaxy, we enter hostile territory.
The closer to the supermassive black hole we travel,
the more dangerous it gets.
As we approach the central core of M87,
we start to feel it.
But all this energy, all this ferociousness,
is powered by that black hole.
ROWE: Intense winds start to buffet the ship.
They push away vital gas, quenching star birth.
Could these winds end up killing
the galaxy and M87 star itself?
ROWE: We're on a mission to explore
the supermassive black hole M87 star.
First, we have to cross the M87 galaxy.
It's 120,000 light-years across,
and it looks like a giant puffball.
M87 is an absolute monster.
It's a giant, elliptical galaxy, and that
means that, as you go from the edges to the interior,
you see a higher and higher density of stars.
ROWE: This vast galaxy contains several trillion stars.
What's strange is that almost all of them are the same color.
So as you see, you are...
Your sky is covered with countless red points of light
everywhere you look.
ROWE: Most of these points of light are small,
long living-stars called red dwarfs.
So what happened to the different-colored
stars that we see in other galaxies?
When you create lots of stars,
you make lots of blue and red stars.
But the blue ones don't last very long.
They explode and are gone.
The red ones, the ones that are lower mass,
those are the ones that live for many, many billions
of years... M87 hasn't made stars
in so long that its stars are mostly red.
ROWE: We call galaxies with mainly red stars,
red and dead.
So the only stars that are left in these
red and dead galaxies are billions of
year-old populations.
And since it's not making new stars,
the clock is ticking on M87.
Essentially, it's a dead galaxy walking.
ROWE: The M87 galaxy
hasn't made any new stars for billions of years.
Something had to make that happen.
Something had to deplete or heat up or push away
the gas in those galaxies that would otherwise go into
forming stars.
We think that black holes in the centers
of galaxies are the ultimate answer to this.
ROWE: So how did M87 star
kill off star formation billions of years ago?
As we cruise towards the supermassive black hole,
we get a clue from the strong winds buffeting the ship.
So these winds can be incredibly powerful and really,
really fast, right?
You think a hurricane on Earth is bad?
You should see some of these winds.
ROWE: In space, winds were made up of gas
and superheated plasma.
The power that generates the winds lies ahead
the bright accretion disk surrounding M87 star.
Because it's so incredibly hot,
it liberates an enormous amount of light,
and that light can drive a wind,
and so black holes can power winds.
They power winds with light itself.
And the more material
that's falling into that accretion disk,
the bigger and hotter it gets, and the more powerful the wind
is that the black hole blows.
ROWE: We understand that light from the accretion disk
creates the winds,
but that is about all we know.
We don't know that much about the wind.
Is it expanding in all directions like a sphere?
Or is it aimed in jets, very narrow
and only moving in two different directions?
Now, measuring the effect of the winds
isn't as easy as you might think.
It's not like going outside on a windy day
and doing one of these.
You have to infer what's going on with the winds
by studying the light emanating from this object.
ROWE: We wanted to find out if black hole winds
expand like a bubble or travel in narrow streams.
So we studied how iron dust from
the accretion disk blocks the light driving the wind.
Astronomers found the answer when they looked
in the X-ray light spectrum.
And what they detected was iron
absorbing those X-rays in every direction
they looked around the black hole.
That's only possible
if the black hole is blowing out a wind in every direction,
which means that it is definitely blowing out
a spherical wind, which is expanding into that galaxy.
And so these black holes can almost literally inflate
this growing sphere bubble
of gas that's outward flowing from the heart of the galaxy.
These winds push out throughout the entire
galaxy of M87,
transporting heat and energy throughout the entire volume of
the galaxy.
PLAIT: What we found is that it's expanding away
from the black hole at a quarter of
the speed of light, 40,000 miles per second.
ROWE: And for the M87 galaxy,
that is bad news, because hot,
powerful winds kill off star birth.
The winds can push away the gas that would have normally
formed stars so they can
effectively quench star formation in a galaxy,
causing it to gradually die.
ROWE: And it gets worse.
In order for a galaxy to produce stars,
it needs lots of gas and dust,
and that gas and dust needs to be incredibly cold.
ROWE: Hot winds from the black hole heat up
gas clouds so they can't collapse into stars.
As M87 star has grown,
it has slowly shut down star formation.
As the black hole in the center of the galaxy grows,
it has stronger and stronger winds,
and this means it's gonna drive out more and more matter.
And that's what makes it a galaxy
that can no longer support star formation.
MINGARELLI: So a supermassive black hole can determine
the star formation happening in the galaxy.
It can help to regulate the amount of gas in the galaxy
and therefore the number of stars that are formed
in a galaxy.
ROWE: Although M87 star is tiny
compared to the vast galaxy around it,
it still controls its host.
When you compare it to the size of the galaxy
it's sitting in, it's like comparing
a grape to the size of the Earth.
So to think that something so relatively small compared to
the galaxy could have such a profound effect over
effectively all of cosmic history is
just this remarkable illustration of how energetic
a black hole can be.
In the relationship between
a supermassive black hole and the material surrounding it,
the black hole is in charge.
ROWE: Although M87 star calls the shots, its past,
present, and future are inextricably linked
to its host galaxy.
The view from our ship is endless space,
calm and unchanging.
But the M87 galaxy has a violent past,
a history of cannibalism,
death, and destruction.
ROWE: We've traveled thousands of light-years
across the M87 galaxy,
but its supermassive black hole
is still far in the distance.
From our current position,
M87 star may look small,
but it's 6.5 billion times the mass of the sun.
So how did it get so big?
One of the big mysteries that we're still trying to
understand is what
controls how big the giant black holes at the centers of
galaxies become.
And we know that it's tightly correlated
with things like how big the galaxy is.
Bigger galaxies have bigger black holes.
ROWE: To understand how M87 star became so big, we have to
investigate the history of its galaxy.
We need to discover how M87 star's host galaxy
grew so large.
M87 is huge.
It's a big galaxy with a big black hole.
TREMBLAY: It's really, really big.
It's what we call the brightest cluster galaxy,
and these so-called brightest cluster galaxies are among
the most massive galaxies in the known universe.
Usually, a galaxy with the mass of M87 is much smaller,
but M87 is puffed up hugely. Why?
ROWE: One lead comes from the layout of M87's stars.
As we travel through the galaxy, we see
that the stars spread out over an area 100 times larger
than expected.
So what scattered the stars?
Galaxies aren't static, every galaxy is moving,
and sometimes galaxies get very close
and can interact with each other.
ROWE: Interact is a polite way
of describing something extremely brutal.
Galaxies are colliding with other galaxies, they're
cannibalizing smaller galaxies or tearing each other apart.
MINGARELLI: Sometimes they're like drive-bys,
and they'll warp each other's structures.
Sometimes the galaxies have head-on collisions and merge.
ROWE: Merging pulls in new gas and stars,
so galaxies grow larger.
Galactic cannibalism is common.
Maybe the M87 galaxy ate its neighbors.
But how can we find out?
We could try to identify stars
that came from the consumed galaxies,
but that's not straightforward.
When you're trying to map out a distant galaxy,
it turns out using their stars is a really hard thing to do.
They smear in with the foreground and the background.
It's actually very difficult to see any
evidence that that galaxy merger ever happened.
It's all smoothed out.
It's kind of like throwing a bucket of water into a pond.
And then asking after the waves go away
to separate which molecules of water came from
the pail of water versus which were in the pond.
All you see is just mixed pile of water,
and it's similar to that with the stars in a galaxy.
ROWE: So how can you spot water from the bucket
in the pond water?
We need to detect signs of disruption,
like ripples or distinct
streaks of sand and mud thrown up
by the disturbance.
When galaxies merge, they may also
leave a leftover that stands out,
like a planetary nebula.
Planetary nebulae are these bright beacons that you can
pick out and map out the galaxy with great precision.
ROWE: A planetary nebula forms when a dying,
mid-sized star blows off its outer layers
after running out of fuel... These outer layers of
gas expand, forming a nebula,
often in the shape of a ring or bubble.
And you see this beautiful, glowing blue-green blob coming
away from the star... these are so much bigger than stars.
You can pick them out very easily.
ROWE: One team went planetary nebula hunting
in the M87 galaxy.
As they mapped the galaxy,
they picked out 300 distinct glowing points.
The points are blue-green, confirming they're
planetary nebulas.
Planetary nebulae are great.
They really stand out like needles in
a planetary haystack.
ROWE: The nebula's movements are distinct
from the stars in M87.
This shows they formed in a smaller, younger galaxy,
not M87.
THALLER: Because we see these planetary nebulae,
something must have happened in this old, dead galaxy.
What was it? A galaxy collision.
ROWE: The discovery of the planetary nebulas
shows that at some point in the last billion years
M87 ate a smaller galaxy.
This galaxy strayed too close to the much larger M87.
M87's powerful gravity snared the smaller galaxy
and dragged it closer and closer.
You could actually see this galaxy getting bigger
and bigger and bigger in the sky,
and it wouldn't stay the same shape... as the galaxy
got closer, it would begin to distort,
and your galaxy would distort, as well, until the sky was
filled with rivers of stars.
M87 pulled in the small galaxy and swallowed it whole.
Can you think of anything more
dramatic than the collision of two galaxies?
ROWE: A violent history of mergers explains how
the M87 galaxy grew so large.
Each event brought in many millions of stars.
The collisions also unleashed enormous gravitational forces,
scattering the stars like confetti.
OLUSEYI: After a collision like this,
the stars are probably ten to 100 times more spread out
than they were before.
ROWE: Some collisions threw stars around.
Others changed the shape of the entire galaxy.
PLAIT: If that galaxy merger is violent enough,
it injects so much energy into the galaxy that the stars
basically all move away from the center,
and it makes the galaxy much more puffy.
ROWE: Gradually transforming it into the smooth, featureless,
elliptical shape.
Most galaxies have a supermassive black hole
at their center,
including those galaxies eaten by M87.
So what happened to those black holes?
Did they merge with M87 star, increasing its size?
M87, the fact that it's an elliptical galaxy also
supports the fact that it's had
multiple supermassive black hole mergers, which is how
M87 star could have gained its sizable mass.
ROWE: Compared to its violent history,
the M87 galaxy is now relatively calm.
We think that in the past,
M87 star grew by gobbling up other supermassive black holes
brought in by collisions with other galaxies.
But we don't really know, because physics
suggests that supermassive black holes can never merge.
Instead, they lock together
in a cosmic dance for eternity.
ROWE: As we travel closer to the supermassive black hole,
we pass the remnants
of smaller galaxies eaten over the last
10 billion years.
They reveal how the M87 galaxy got so vast.
Most of these consumed galaxies probably had
a supermassive black hole of their own.
If M87 got so large by eating galaxies,
did M87 star get supermassive
by consuming other supermassive black holes?
So when galaxies merge, all their stars and nebulae
mix together, and then also there supermassive black holes
eventually find each other and find their way down to
the center of the newly merged galaxy.
Just like dropping two stones into a pond,
they'll both reach the bottom.
They'll both move toward the center,
and they will start to move ever closer together.
ROWE: But do the supermassive black holes
actually collide?
We've witnessed the merging of smaller,
stellar mass black holes,
and we've seen supermassive black holes get close together,
but we've never observed them merge.
When galaxies merge, their central,
supermassive black holes should merge.
The first step in the merger process,
they're sinking toward the center of
this newly formed galaxy.
ROWE: As they plunge towards the galactic center,
the supermassive black holes plow through fields
of stars and clouds of gas.
They don't just run into each other,
they inspiral toward each other, so they're gonna
scatter stars everywhere, and the closer they get
the more rapidly they will orbit each other.
So things get even more and more chaotic and crazy.
ROWE: In all the chaos, something strange happens.
The supermassive black holes stop moving
closer to each other.
This is a problem, and we call this the final parsec problem.
ROWE: So what's going on?
Why do they stall?
MINGARELLI: The final parsec problem
happens when two supermassive black holes run out
of material to help them to merge.
If there's not enough stars or gas
that the black holes can interact with,
it takes longer than the age of
the universe for them to lose enough energy to merge.
And so the black holes effectively stall
at this final parsec of separation.
ROWE: The two supermassive black holes lock
together in an eternal cosmic dance,
close but forever apart.
But some supermassive black holes must have merged.
It's highly likely that many of
the galaxies M87 swallowed had supermassive black holes.
And yet, on our trip,
we haven't seen lots of supermassive black holes,
just one... M87 star.
So mergers take place, but how?
In 2019, we got a clue
from a galaxy called NGC 6240.
This particular galaxy looks like
the aftermath of a massive galactic collision.
There are lumps and clumps of stars,
random groups at random directions
and random velocities.
It's all mixed up, which is what we think
galaxies look like after a massive merger.
ROWE: The merger aftermath reveals a more
complex series of events than a two-galaxy collision.
What we find in the center of this galaxy isn't two,
but three giant black holes,
which suggests that there have been three galaxies
colliding in recent history.
MINGARELLI: So when this new galaxy starts to merge
with the galaxy that hosts the stalled pair,
it brings in its own third supermassive black hole.
Now this supermassive black hole perturbs the system,
and it makes what's at the center highly unstable.
ROWE: The gravity of this third supermassive black hole steals
orbital energy from the stalled pair,
pushing them closer together.
It's almost a thief that comes in and takes away
some of that rotational energy from this binary
black hole system.
ROWE: As the two supermassive black holes
lose orbital energy, they finally come together.
The likeliest thing to happen is that the least massive
supermassive black hole is ejected.
And the remaining two merge very quickly.
ROWE: The high-speed merger will last just milliseconds,
but it will trigger
[explosion blasts]
A gigantic explosion.
SUTTER: When these giant black holes merge,
more energy is released in this process than our entire
galaxy will emit
over the course of billions of years.
ROWE: Perhaps M87 star merged
with other supermassive black holes
in the same way...
A third black hole, helping it
to overcome the final parsec problem.
It's possible that mergers with other supermassive
black holes allowed M87 to reach its sizable
mass of 6.5 billion solar masses.
ROWE: Supermassive black holes meet their match
when they square off against each other.
The fallout is cataclysmic,
and as we get closer to M87 star,
our mission becomes more dangerous.
We enter the gravitational kill zone
surrounding the supermassive black hole.
We know the dangers.
Any unwitting stars that get too close are
stretched, shredded,
and torn apart,
creating one of the biggest
and brightest light shows in the universe.
ROWE: As we get closer to M87's
supermassive black hole,
we enter dangerous territory, not just for us,
but also for wandering stars.
If the black hole snares them,
they are toast.
But their death may solve one
of the mysteries of supermassive black holes...
How fast they spin.
It's difficult to calculate just how fast
a featureless black object hidden by
a bright disc rotates.
You need a lot of patience and a little bit of luck.
Astronomy is sometimes a pretty opportunistic science.
You have to be looking at the right place at
the right time to figure out something new
that we've never seen before.
ROWE: Recently, astronomers caught a break
when they spotted an extremely bright flare
in galaxy PGC 043234.
It was hard to miss.
The flare was 100 billion times brighter than the sun.
And the energy output was absolutely ridiculous.
If this happened in the center of our galaxy,
it would have been so bright, we could see it during
the daytime.
[explosion blasts]
ROWE: A routine search for supernovas,
violent deaths of giant stars, detected the intense flash.
ASAS-SN is this network of telescopes
designed to look for brief,
high-energy events all around the sky,
and primarily supernova.
They saw a bright flash, and they thought, "Oh, yay,
another supernova."
If you see a bright flash of light coming from a galaxy,
that's kind of your first thought.
But it didn't look like a supernova at all.
It didn't act like a supernova flash would.
It didn't have the right characteristics.
It wasn't behaving like a typical supernova.
It had to be something else.
SUTTER: So they send out an alert to
the astronomical community, saying, "Hey, there's something
cool happening in this region of space."
Once an event is flagged as real,
then what happens is other telescopes turn their attention
to that event.
ROWE: The data revealed something strange.
SUTTER: After the initial flash,
there are still smaller flashes that repeat, and if
you're gonna kill a star in a supernova,
there's nothing left to repeat like that.
Intriguingly, it flashed on
and off about once every 130 seconds.
ROWE: The flashes continued for 450 days.
PLAIT: When astronomers looked at this galaxy in detail,
they saw that this event happened right at the center,
and there's a black hole there with about one million times
the sun's mass, and that was... That's it, man.
That's the smoking gun.
ROWE: What they observed was an extremely rare phenomenon,
a tidal disruption event.
SUTTER: Catching one live as it happens
is an astronomer's dream.
This was our first time catching a black hole in
the act of feeding on a star.
In galaxy PGC 043234,
a star wandered too close to
a supermassive black hole.
SUTTER: As this unfortunate star got close to the black hole,
the black hole is spinning,
and the gravity around this monster black hole is so strong
that it could pull the star apart.
PLAIT: The side of the star closer to the black hole
is feeling a much, much stronger
gravitational pull toward the black hole than
the far side of the star, because it's farther away.
And what this does is it stretches the star.
SUTTER: So it got ripped to shreds, it got shredded.
It got pulled out and stretched
and whipped around the black hole.
And this stretches the star into some giant long arm,
and that swirls around and is trapped as it orbits
the black hole.
ROWE: The accretion disk snares the shredded star.
OLUSEYI: And what this means is that that accretion disk is
gonna increase its output of radiation, in particular,
high-energy radiation.
ROWE: As the star embeds in the accretion disk,
a massive flare of radiation erupts,
lighting up the universe.
After this initial burst,
the spinning star debris sends out
a continuous stream of light.
Our telescopes only pick up this radiation
on each rotation of the disk.
It's like seeing the beam from a lighthouse every 130 seconds.
The flashes are the final pulses of a dying star,
and those flashes reveal both the width
and the rotation speed of the supermassive black hole.
We learned that the central massive black hole
is about 300 times wider than the Earth,
but it's rotating every two minutes.
It's rotating at half the speed of light.
ROWE: That's over 300 million miles an hour.
We don't yet know how fast M87 star is spinning,
but we do know the accretion disk rotates it over
two million miles an hour.
This glowing ring, hundreds of light-years wide,
now lies directly ahead of our ship.
It is one of the most awe-inspiring
and deadly places in the universe,
and we are heading straight for it.
ROWE: After our long trek across the galaxy,
we finally face the mighty
supermassive black hole at its center... M87 star.
A dazzling glare confronts us.
This is the accretion disk, a ring of hot gas and dust
spinning at over two million miles an hour.
M87 star's accretion disk
is so bright, the Event Horizon Telescope
photographed it from Earth 55 million light-years away.
So I remember exactly where I was
when that image was released... I was sitting with a bunch of
my colleagues at the Center for Astrophysics,
and we were all watching the press conference live and
just absolutely slack-jawed when that image hit the screen.
OLUSEYI: I was sitting in the airport
when I saw this black hole image,
about to take a flight to New York.
I got so excited that I actually
walked away from my backpack sitting there.
TEGMARK: Seeing that picture,
it really doesn't leave room for doubt.
Black holes are real.
ROWE: The Event Horizon Telescope photo is
the first picture ever taken of a black hole.
The image revealed M87 star
spins in a clockwise direction,
and it's 23.6 billion miles wide.
That's around three million Earths lined up in a row.
The photo also confirmed M87 star's
membership in a very exclusive club...
The 1% of supermassive black holes that actively feed.
The image from the Event Horizon Telescope
tells us that M87 is indeed
actively growing and accreting and eating material
around it... it shows gas swirling around that black hole
on its way to being swallowed.
ROWE: But do all supermassive black holes consume material
in the same way that M87 star does?
Is it possible that different black holes
have different table manners?
Well, it turns out that's really true.
Some are more delicate eaters.
ROWE: In 2018, we discovered a supermassive black hole
250 million light-years from Earth that eats on a schedule.
Now we have this case of a black hole
that looks like it's feeding three times a day.
It's having three square meals a day.
ROWE: Intense bursts of energy pulse out
from galaxy GSN 069.
We see X-ray flares and bursts
coming from the center of this galaxy,
repeating every nine hours, and each burst is associated
with a new feeding event.
ROWE: This supermassive black hole not only
eats on a schedule,
it has a very healthy appetite.
Each one of these meals that this black hole is consuming
is the equivalent of four of our moons in a single bite.
ROWE: So what exactly is this supermassive
black hole consuming?
The most likely contender is a star.
We think that the star has been ripped apart
and spread throughout an accretion disk, and then
slowly over the course of hours,
an instability builds up, and some material falls in.
ROWE: When the infalling material from
the star hit the supermassive black hole,
it triggered a burst of X-rays.
Then, the system stabilized...
until it sparked up again,
creating a nine-hour cycle of bursts of energy.
Then, in 2020 new observations spawned a different theory.
The star wasn't caught on the accretion disk.
The supermassive black hole had instead pulled it into orbit.
Its orbit takes it near that black hole every nine hours,
and every time it encounters the black hole,
some of its material gets sipped off.
ROWE: Eventually, the GSN 069 supermassive
black hole will lose its meal ticket.
But it's luckier than many other supermassive black holes.
Sometimes black holes just take a little nibble on
the surrounding material and just give
a little burp of radiation in response.
ROWE: A black hole burp generates strong
shockwaves that radiate out across the universe.
We detected two of these energy outbursts
in galaxy J1354+1327,
located 800 million light-years away.
The huge burps suggested that the supermassive black hole
at the core of this galaxy was snacking.
It ate a bunch of material one time
that caused a burst of energy flowing outward.
Then it feasted again, and that caused another burp.
ROWE: What caused these separate outbursts?
The belching black hole galaxy has a smaller companion galaxy.
A gas stream links the two galaxies,
supplying an intermittent, on-off food supply.
There's actually a smaller satellite
galaxy going around the bigger galaxy.
The black hole in the middle is
pulling streams of material off this little galaxy.
ROWE: Clumps of material from the companion galaxy
move toward the center of J1354.
Once there, the supermassive black hole grabs them.
Some gas streaming from the neighboring galaxy
reaches the center of
the bigger galaxy when the black hole feeds
and then ejects a jet.
ROWE: When supermassive black holes like the one in
J1354 receive an irregular supply of food,
a cycle is established,
a routine that scientists call feast...
burp...
nap.
The supermassive black hole we're headed towards, M87 star,
doesn't do burp and nap.
It feasts all the time.
Stars come in and get ripped apart,
maybe once every 10,000 or 100,000 years.
Whereas M87 has been shining brightly for millions of years.
It clearly has a supply of gas other than ripped apart stars
that's feeding the accretion disk.
ROWE: This helps explain how M87 star
grew to 6.5 billion solar masses.
But what about the future?
Will this supermassive black hole continue to feast,
or will it starve?
To find out, we have to move even closer,
across the accretion disk, to discover just
how M87 star satisfies its insatiable appetite.
ROWE: Our ship passes over the accretion disk of M87 star,
a blazing ring of gas and dust hundreds of light-years across.
This is the supermassive black hole's grocery store.
Black holes are known for sucking in everything.
But is that really true?
Black holes don't really suck.
It's a popular misconception.
They don't just pull anything in.
In fact, if the sun just instantly turned
into a black hole today,
the Earth would happily continue on in its orbit,
because all that gravity cares about is
how massive and how far away something is.
ROWE: Supermassive black holes like M87 star
are a lot more massive than a regular sun-sized black hole.
This means their gravity is greater and extends much
farther out into the galaxy,
allowing supermassive black holes to attract dust,
gas clouds, and stars from billions of miles away.
But they don't gulp down everything they pull in.
OLUSEYI: The way black holes eat matter
isn't as straightforward as you might imagine.
Earth gains mass every day from
objects falling to it from space.
So you might imagine that matter
falling onto a black hole is
like meteorites falling onto Earth.
They can come in from any direction and land anywhere.
That's not the case around a supermassive black hole.
The most efficient way for a black hole to consume matter
is for it to grow an accretion disk.
ROWE: Accretion disks grow when gas and dust
dragged in by the supermassive black hole's
gravity spirals inward and piles up in a ring.
The ring starts to spin from the combination of gravity,
and the momentum of the gas and dust.
The spinning material flattens into a disc.
The material doesn't fall straight in.
It orbits its way in,
and so it gets accelerated to incredibly fast speeds.
Sometimes, the matter ends up inside the black hole.
Sometimes, the matter ends up getting
kicked away from the black hole.
ROWE: As we traveled through M87,
we witnessed jets and winds
from the supermassive black hole blast this material
out into the galaxy.
But there may be other things that
stop food from entering a black hole.
HOPKINS: The black hole at the center of
our Milky Way galaxy, what we call
Sagittarius A star, appears to
be swallowing material or eating at an incredibly low rate.
ROWE: To discover what's stopping Sagittarius A star,
or Sag A star for short, from feeding,
scientists studied infrared light moving out from
the supermassive black hole.
To do that, they needed to fly high in Earth's atmosphere.
The problem is, water vapor in our atmosphere prevents
the infrared light from space from getting down to the ground.
SOFIA is an infrared telescope built
into the side of an airplane.
As bizarre as that is, it's a very stable platform.
SOFIA can look at these objects emitting infrared
in space and get really good observations of them.
ROWE: SOFIA focuses on the structure of the gas in
the strong magnetic fields at the center of the Milky Way.
This high-resolution telescope can track
the finest grains of dust.
When all the dust grains in a cloud are aligned by
a magnetic field,
they scatter the light coming at them in a certain way,
and we call this polarized light.
The dust grains can actually map out the magnetic field
embedded in that dust cloud.
ROWE: The telescope picked out
the grains arranged in a spiral pattern
and revealed the direction the grains were moving.
This movement reveals why Sag A star is starving.
The magnetic field is channeling them into
orbit around the black hole
instead of allowing them to fall in.
So it's literally keeping those dust grains
away from the black hole.
ROWE: The magnetic fields also pushed clouds of gas,
Sag A star's food source, away from
the supermassive black hole.
This is the situation now, but that's not necessarily
the way things are always going to be.
ROWE: Because magnetic fields can switch directions.
PLAIT: There's a lot of other junk out there, dust and gas
and other stars, that as they get close,
they can change the magnetic field, and that might allow
that dust to fall into the black hole.
ROWE: Magnetic fields changing direction
offers hope for Sag A star.
And magnetic fields could help M87 star feed.
Our mission continues, following this material
plunging down into the supermassive black hole,
We set a course towards the event horizon,
the boundary between the known and the unknown universe,
where the laws of physics no longer apply.
ROWE: Our ship crosses the accretion disk.
Ahead, the absolute darkness of
the supermassive black hole, M87 star.
According to black hole legend,
this is where we meet our end, torn to shreds by gravity.
We have so much wonderful imagery of what would happen if
you were to fall into a black hole from science fiction.
One idea that has caught popular attention
is the notion that
you get spaghettified when you fall into a black hole.
This is me. This is a black hole,
which is pulling stronger on my feet than on my head.
And if this black hole is a little bit heavier
than our sun, this difference
in pull is so strong that I would actually
get spaghettified, torn apart.
ROWE: So will M87 star spaghettify us?
The answer depends on the black hole's mass
and volume ratio.
A stellar mass black hole with the mass
of 14 suns is just 26 miles across.
That's about the size of Oklahoma City.
Such an enormous mass in a small volume
creates a very sharp increase in gravitational tidal forces
as you approach the black hole.
With a small black hole,
the strength of gravity changes so rapidly
with distance that your feet could be pulled
a million times harder than your head.
But with supermassive black holes, that doesn't happen.
ROWE: The mass of a stellar mass black hole
is concentrated in a small area.
A supermassive black hole's mass spreads much wider over
an area a billion times larger,
so its gravity increases gently as you get closer.
This means approaching a supermassive black hole feels
more like walking down a slope
rather than jumping off a cliff, so it won't rip you to shreds.
Supermassive black holes have a bad reputation.
That bad reputation firmly belongs to stellar
mass black holes that rips things to shreds.
TEGMARK: The nice thing about supermassive black holes is
these so-called tidal forces are much weaker,
so I would actually be just fine and be able to take in
this really bizarre scenery around the black hole,
with light from distant objects being bent out of shape.
ROWE: So we can approach M87 star safely.
Once there, we are faced with an awe-inspiring sight.
The supermassive black hole distorts the light around it.
Far away from the black hole,
that warping isn't very strong, but the closer
the light gets to the black hole,
the more severely its path is distorted, and the starlight
around the black hole becomes really bizarre.
They get stretched into... Into rings and arcs.
ROWE: We can even see things hidden behind
the supermassive black hole.
I would see, for example, the galaxy behind here looking
completely warped out of shape,
because light is bent around the black hole.
Black holes can even bend light so it comes from my face,
goes around and comes back on the other side.
So I could, in principle, use a black hole,
you know, as a mirror when shaving.
SUTTER: To really understand
what's happening around a black hole,
we need to understand gravity, and the language of gravity is
the language of spacetime.
ROWE: Spacetime binds the whole universe together.
If we could put on special spacetime glasses,
we'd see stars,
planets, and galaxies floating on a grid of spacetime.
These objects have mass,
and mass distorts and curves spacetime.
Imagine a trapeze artist with a flat net underneath them.
When they fall from the trapeze onto that net,
the net distorts. It forms a dimple
right where that trapeze artist is.
The trapeze artist is like a black hole.
The net is like the fabric of space
and time distorting because of the mass in it.
ROWE: This distortion of the spacetime net
by objects with mass is called gravity.
The more massive you are,
the more gravity you have, because
the more you bend and stretch spacetime.
So one trapeze artists may bend the net a little bit,
but a hundred trapeze artists
will bend that net a lot, and good luck
trying to walk across it.
ROWE: M87 star's
immense gravity bends space, forcing light
to travel along the curves.
But what does it do to the other half of the equation,
time?
Einstein realized that time actually runs slower
near a black hole than back on Earth.
ROWE: It's a process called gravitational time dilation.
Viewed from a distance, our ship
appears to move in slow motion.
But what do we see on board the craft
as we approach M87 star?
You would perceive time to proceed on normally.
You'd look at your watch, and that second hand
would be going around the dial just like normal.
But to an outside observer,
that apparent one minute on your watch could take millions
to even billions of years.
If I'm having a Zoom conversation with mommy
back home, even though I'm feeling
I'm speaking normally, she would hear me go,
[exaggeratedly slowly] Hi, mommy.
[normally] And this is not some sort of illusion.
My time really is going slower.
So when I come home, she'd be like, "Hey, Max, you look"
so good, you look so youthful," and I would actually
have aged less, because time ran slower over there.
ROWE: On our final approach into M87 star,
we reach a crucial milestone.
We are now at the innermost stable orbit.
We go any further, we're not getting out ever.
You have two choices.
You either escape to safety or you fall into the black hole.
ROWE: Well, that's easy.
We detach the probe to approach the black hole alone.
You can think of the event horizon as being the surface of
a black hole, but that's a little bit of a misconception.
There's not actually anything there.
That's just the distance from the center,
where the escape velocity is the speed of light.
ROWE: Because nothing can travel faster than light,
nothing can escape a black hole.
Think of the event horizon as a waterfall.
OLUSEYI: If you imagine the flow of water over a waterfall,
if you're a fish, you could swim
up close to that edge and still escape.
But if you go too far,
you hit the point of no return, and you're going over.
ROWE: At the event horizon,
the water moves faster than the fish can swim
or our probe can orbit,
so the waterfall, or gravity, carries them over
and into the black hole.
But what about the light around them?
Imagine that fish that's going over
the waterfall is carrying a flashlight.
Say it's an alien fish.
At a black hole,
If that fish goes over that event horizon, not only does
the fish and the flashlight get sucked in,
but the light of the flashlight get sucked in.
TREMBLAY: There's nothing that can turn around.
Light, matter, cows, elephants that passes through
the event horizon can never come back out.
It is a one-way ticket.
ROWE: A one-way ticket through the event horizon.
Back on the ship, though, we don't
see the probe entered the supermassive black hole.
Instead, from our perspective,
the probe just gets slower and slower and slower and slower.
ROWE: Until it appears that time simply stops
for the probe,
frozen by the enormous gravity of M87 star.
The probe appears stuck, glued to the surface.
But that's just our perspective.
In reality, the probe has already crossed
the event horizon and is inside the black hole.
ROWE: If only it was that simple.
The two major theories that explain how the universe works
don't work at the event horizon.
General relativity says the probe enters
the black hole,
but quantum mechanics throws up some major hurdles.
According to some ideas rooted in quantum mechanics,
there may be something called a firewall,
a wall of quantum energies that prevents material from
actually reaching through the event horizon.
ROWE: The question of what happens
to anything attempting to cross
the event horizon has challenged some of the greatest
minds in physics.
Will our probe enter the supermassive black hole,
or will it be burnt to a crisp in a wall of fire?
Our probe is approaching the event horizon of M87 star,
but there's a problem.
The two major theories that explain how the universe works
don't agree about what happens next.
One says the probe passes through unscathed.
The other theory says that's impossible.
It suggests the probe hits
an impenetrable barrier called a firewall.
How can the same event have two different outcomes?
There's a really interesting puzzle right now, which is
where general relativity and quantum mechanics meet,
and it's called the Black Hole Information Paradox.
What we have is a very schizophrenic situation
in physics, where we have
two theories that just don't get along.
Einstein's theory of gravity explains all the big stuff.
Quantum field theory explains all the small stuff.
So which one is right and which one is wrong?
This is the mystery.
ROWE: General relativity says,
in theory, crossing the event horizon is no big deal.
If you're passing through the event horizon,
you wouldn't notice anything different.
MINGARELLI: You can, in fact, cross the event horizon
of a black hole like M87 star in your spaceship,
without even knowing that you have, nothing would change,
you'd just peacefully drift inside.
ROWE: According to general relativity, our probe crosses
the event horizon and enters the black hole.
Quantum mechanics sees it differently.
When it looks at the probe,
it doesn't see a robotic spacecraft.
It sees information.
THALLER: Everything at a quantum mechanical level
has information.
You can think of things like a particle having a charge.
Particles have spin, angular momentum, and that information,
as far as we understand, can't be destroyed.
ROWE: What do we mean by destroyed?
Well, think of burning a book.
The words are information.
As each page burns, the words disappear.
The information is gone, but not really.
If you could track every single thing that
was happening, track each smoke particle,
put everything back together again,
in principle, that information is still there.
ROWE: Because information can't be destroyed,
the probe's information, even if mangled,
should be inside the supermassive black hole.
If the information that fell into a black hole just stayed
locked inside of a black hole, that'd be fine.
That doesn't violate any physics.
ROWE: But Stephen Hawking threw a wrench in the works
when he theorized that, over time,
black holes evaporate, slowly shrinking particle by particle,
emitting heat known as Hawking radiation.
Hawking radiation itself doesn't carry any
information out, and Hawking radiation
eventually destroys a black hole.
Eventually, the black hole evaporates and disappears.
ROWE: As the black hole vanishes, so too,
does information about the probe.
This is a big problem for quantum mechanics.
Can black holes really
destroy information even though
quantum physics suggests you cannot?
So is the foundation of quantum mechanics wrong?
This is the Quantum Information Paradox.
ROWE: To try to prevent this impossible situation,
scientists came up with a workaround,
something that prevents the probe's information
from ever entering the black hole,
the firewall.
Quantum mechanics says that there is this
quantum fuzz causing there to be
ridiculously high temperatures literally burning
you up as soon as you enter.
ROWE: If the firewall incinerates the probe,
then its information will stay in the ashes of the ship,
just like the words from the burning book.
So which theory is right?
Does the probe safely enter the black hole?
Or does the probe burn up?
I've actually spent an afternoon at Caltech arguing
with people about whether anything
falls into a black hole or not,
and the answer is we don't really know.
ROWE: To find an answer,
scientists have come up with some crazy ideas.
One, called quantum entanglement,
suggests that the probe is both inside
and outside the black hole,
its information carried by particles constantly popping up
on either side of the event horizon.
And Stephen Hawking,
whose original idea that black holes lose information through
heat, also came up with a solution.
He suggested that black holes have soft hair.
Traditional black hole science says they're bald.
By which we mean that they have
no features at all except their mass,
and their charge and their spin that you can measure
from outside.
ROWE: Hawking's updated theory says that black hole hair
is made from ghostly quantum particles,
which store information.
Thermal radiation from the evaporating black hole
carries this information away from the event horizon.
If Hawking is right,
the probe's information will eventually escape
into the universe.
The concept of black hole hair
would solve the Black Hole Information Paradox
if it exists, but we don't know if
black holes have hair or if they're, you know, bald.
ROWE: Until we can unite quantum mechanics
and general relativity at the event horizon,
the Information Paradox will
remain a problem for physicists.
It's one of the most embarrassing problems
in physics, which is still unsolved.
I hope one of you who watches this
will become a physicist and solve it for us,
because physics is far from done.
ROWE: The failure to solve the Black Hole
Information Paradox throws up a major obstacle
to our understanding of how our universe works.
This is the point where physics hits a wall.
While a search for a solution continues,
let's assume our probe dodges
its way past the Information Paradox.
It sails across the event horizon towards one of the most
violent places in the universe,
the core of M87 star.
It's called the singularity,
and there are no rules.
Nothing makes sense,
and nothing escapes.
ROWE: Our probe has crossed the event horizon.
It's on a one-way trip to
the heart of the supermassive black hole M87 star.
OLUSEYI: Anything that crosses the event horizon
is not coming out... It's like Vegas.
What goes in a black hole stays in a black hole.
ROWE: The probe leaves the physics we understand
and enters the world of physics we do not.
This probe is now moving faster than light
or being carried by space itself faster than light.
Once you cross the event horizon of a black hole,
your future lies on the singularity in the center of
the black hole... there's no escaping the fact that
you will eventually join the singularity.
OLUSEYI: The space inside of a black hole
is like a 3D spinning vortex.
The space in there is always moving.
This is the nightmare version of the carousel ride.
ROWE: The whirling probe hurtles downwards, until it hits
an even more bizarre region of the black hole...
the inner event horizon.
You thought the firewall was bad,
but that's peanuts compared to the inner event horizon.
Theoretical physicist Andrew Hamilton believes that all
light and matter that's fallen
into a black hole piles up in a tremendous collision at
this location.
The inner event horizon would be infinitely violent,
because it's like the meeting point between two universes.
ROWE: This meeting point is like water falling and smashing
into spray, shooting back up
from the rocks at the base of the falls.
Inside the supermassive black hole,
space races in and crashes into rebounding space at
the inner event horizon.
SUTTER: This would be a place of infinite energy.
It's a place where infalling material, into the black hole,
meets outflowing material.
ROWE: Everything falling into M87 star smashes together in
a monumental release of energy.
This energy has got to go somewhere.
It's possible that this inner event horizon is so energetic
that brand-new universes could be born in this space.
But the question is, how do you actually sort of birth
a new baby universe?
ROWE: The energy created at the inner
event horizon could compress down into
one tiny speck, which suddenly ignites,
[explosion blasts]
Sparking baby universes into life
in their very own Big Bangs.
We know that, a long time ago, our own universe was very small,
very hot, and very dense.
It's possible that it could have been born in
the inner event horizon of a spinning black hole.
This is such a tantalizing
and very hypothetical idea,
but if it's correct,
it gives us insights into the origins
of our universe itself.
Do we have strong evidence
that black holes create baby universes? No.
Do we have strong evidence that they don't? No.
ROWE: If the probe survives the inner event horizon,
it then heads towards the strangest place in the universe,
the core of a supermassive black hole.
The singularity.
As the probe gets closer and closer to the singularity,
the probe gets further and further away from
known physics.
We don't know what the probe
will encounter when it reaches the singularity.
We don't know what it will find.
We don't know what it will experience.
We don't know.
ROWE: In other words, there's a lot we don't know.
Like what exactly is the singularity?
It's a hard question to answer.
Traditional science says it's an infinitely tiny point,
but that's not the case with M87 star.
What's interesting is that if your black hole is spinning,
the singularity is not a point, but it's, in fact, a ring.
ROWE: Physics says the singularity
is infinitely dense.
A point of space and time that is...
It's collapsed as far as it will go,
it basically has infinite density in zero size.
ROWE: For many scientists, that's a big problem.
I do not like singularities.
I feel that they sound really un-physical.
The word singularity sounds so intimidating and scientific,
but it's honestly just our physicists' code word for,
"Uhh, we have no clue what we're talking about."
OLUSEYI: Where else in nature do we find infinities?
We're talking about a region
that would have infinite density and
infinitely small volume, basically zero volume.
How could that exist? I just don't see it.
We just don't know.
And frankly, we will never know for sure.
ROWE: Perhaps the probe breaks up and joins material
consumed by M87 star over billions of years.
Compressed down, not just to atoms, but to a sea of energy,
absorbed into a ring of zero volume and infinite density.
Or there could be another possibility.
Maybe the singularity doesn't destroy the probe at all.
Maybe the probe travels straight on through
and passes into another universe.
ROWE: Our voyage to the heart of M87 star
has been a wild ride.
We crossed the event horizon and fell towards
the singularity,
the core of the supermassive black hole.
Is this the end of our journey or just the beginning?
It could be that the singularity isn't
the end point of the probe's journey.
It could be that the probe passes through
the singularity and enters into a new universe.
ROWE: Our probe has another option,
an escape route out of M87 star.
In our universe, we have black holes,
objects where, if you enter, you can't escape.
It's also theoretically possible for there to be
white holes,
objects that you can't enter, you can only escape from.
A white hole is basically a black hole running backwards.
ROWE: Some physicists have theorized that white holes
may link to the singularities of black holes,
connected by something called a wormhole.
TEGMARK: There have been interesting papers written
suggesting that you could have a wormhole where
something that falls into a black hole here comes out of
a white hole somewhere else.
ROWE: It sounds like a great way
for the probe to escape certain death, theoretically.
A wormhole is the bridge
in spacetime between those two things.
It's easy to create in mathematics.
It very well might not exist in real life and will almost
certainly live out on our entire civilization
and never know about it.
ROWE: That's because constructing a bridge
between a black hole and a white hole
creates a few issues.
A, we don't know how to build them for sure.
B, they might be unstable and collapse on
themselves immediately, unless you invent...
Have some new, weird sort of matter that
can support them.
OLUSEYI: The problem is that
it's hard to maintain this bridge open.
It's not likely that they would ever have
any practical use because they're just not stable.
ROWE: But if M87 star does have a stable wormhole linked to
its singularity, where might our probe end up?
It could be that this probe's journey doesn't end at
the singularity,
and all the information that it carries with it could be
deposited in some distant corner of our own universe.
ROWE: Or perhaps in a different universe.
One idea that sounded like science fiction
decades ago is actually now considered potential reality,
and that's the idea of parallel universes.
If parallel universes exist,
then some surmise that a black hole could be a gateway
to a parallel universe.
ROWE: If there are parallel universes,
who knows which one our probe may end up in.
This universe may be just like our own, or
it might be something completely different.
We'll never get to find out unless we follow in after it.
It could all work out just fine,
and that probe just sails on through
and gets to explore new adventures.
We don't know. Only the probe knows.
ROWE: Supermassive black holes are some of
the strangest and most fascinating objects in
the universe.
Ever since Einstein's Theory of Relativity
predicted black holes a century ago,
we've been trying to understand how they work.
The photograph of M87 star confirmed many theories,
but there is still much to learn about the birth,
life, and death of these remarkable objects,
and even more to leave us fascinated.
This is the ultimate unknown.
This is the real Wild West.
This is the frontier of human knowledge.
MINGARELLI: I care about supermassive black holes
first and foremost because they are awesome.
They stimulate my childhood
imagination and fascination.
HOPKINS: Supermassive black holes offer us
a truly unique window into how the laws of physics work,
especially the laws of gravity in extreme regimes far beyond
anything that we can possibly imagine here on Earth.
THALLER: Supermassive black holes lurk at the heart of
almost every large galaxy that we know of.
So in some way, we're just sort of
all along for the ride with the supermassive black holes.
If I could make a request for one special favor
I would get before I die,
what I would like to do is to get to just spend a few
hours orbiting the monster black hole in the middle of
the galaxy... what a way to go.