The Universe (2007–…): Season 1, Episode 12 - Most Dangerous Places - full transcript

In the beginning there
was darkness and then

BANG!

giving birth to endless expanding
existence of time, space and matter.

Now see futher that we ever imagined

beyond the limits of ours existence

in the place that
we called the Universe.

The Universe is vast

wonderous, electrified.

But for space travellers that looking for thrill ride

it could be a one way ticket

It is a place from which you cannot return.



Or at least, not in the form that you went in.

go and no one has dare to venture.

take a virtual tour of the deadiest
placies of our galaxy

and beyond

most dangerous places

It is the ultimate frontier adventure,
Space Travel

But when trekking through the galactic jungles

One must steer clear of the cosmic, hot zones

Places teeming with violence and intrigue.

There are dangerous places certainly
very energetic phenomena

That are a lot more powerful than
atomic bombs being detonated

Infinitely more powerful.

The universe does seem to be a very violent place.

It seems to have been born in a
violent explosion called "The Big Bang"



And there is also violent processes going on.

On december 27, 2004

Satellites picked up the greatest cosmic
explosion ever recorded

A blast 30,000 light-years away

Which had the power to briefly alter
our planet's upper atmosphere.

The blast was caused by a magnetar

The densest and one of the most
dangerous stars in space.

The magnetic field strength of a magnetar is about

A thousand trillion times the magnetic
field energy of the Earth.

And for reference

This would wipe the information off a credit card

At a distance of about 100,000 miles away.

Now, this distance is sort of half
the distance of the moon

So it's very nearby by astronomical standards.

These mischievous stars have the strongest
magnetic field in the Universe.

Scientists have confirmed 12 of these
rare stars in our galaxy

And there may be more.

Caltech's Brian Cameron

Scans the milky way for these strange stars.

Magnetars are a special class of neutron stars

With ultra strong magnetic fields

The densest form of matter in the Universe.

The first magnetar showed itself in
the form of a high-energy event

That was detected in the late'70s

Although at the time

We didn't know that it was a magnetar.

It wasn't until the early'90s

That researchers suggested that

these objects were dominated by magnetic fields

And that the magnetar theory was actually confirmed.

Magnetars are born out of the
death throes of massive stars.

When a star dies

It begins to collapse and go supernova.

Sometimes, a dense neutron star

Forms from the centers of that supernova explosion.

During the process

A few neutron stars become magnetars

Which possess a strong magnetic field.

These stars eject high-energy emissions
of x-rays and gamma rays.

We think that normal neutron stars are born from regular stars

That are something like 10 or 20 times the mass of the Sun.

But there's evidence that

magnetars are born from possibly even more massive stars

Than this, something like 40 times the mass of the S un.

Typically

A star of such mass would be
too heavy to form a neutron star.

Instead, its mass would collapse into a black hole.

Black holes are formed

From cramming a certain amount
of mass in a certain volume.

And for whatever reason

These stars are unable to do that.

One theory is that some massive stars

Undergo a weight loss program right
before exploding as a supernova

Losing 90 percent of their mass.

So instead of collapsing into a black hole

The emaciated star becomes a neutron star

With extreme magnetic powers.

When the magnetic force gets incredibly strong

It deforms the magnetar's crust

Creating seismic events called "starquakes" on its surface.

Eventually, if this crust breaks under the stress

And the magnetic field reconfigures
itself into a lower energy state

And when this happens

A fireball is launched off the side of the star.

So starquakes on neutron stars' surfaces are thought to

give rise to these giant flares that we see.

After a magnetar undergoes one of these flares

It outshines all the stars in the galaxy

For a few--For the few tenths of
a second that it's taking place.

Within these giant flares

Are short bursts of gamma rays,
which move at the speed of light.

The giant flares from magnetars are gamma ray bursts.

They're very short in duration??Less than a second

And have very hard x-ray spectra

Compared to another class of gamma ray bursts.

If a deep space traveler veered off course

And was unlucky enough

To pass within 700 miles of one of these massive objects

The consequences would be horrific.

The magnetic field of the magnetar

Can literally warp the atoms in human flesh

And its gravitational forces would tear a person apart.

So then, how close would a magnetar have to be

To wreak havoc in our solar system?

Some suggest

That a blast from a magnetar even 10 light-years away

Could produce cosmic chaos

That would destroy our ozone layer

And cause mass extinctions.

The chances of that happening are so low that, you know

They're completely implausible.

It would be no different than

a regular star passing through the solar system.

And we know that a regular star

Has not passed through the solar system

Since this solar system was formed.

Scientists think

That magnetars are only a few thousand years old

And will become dim after 10,000 years.

We're just now starting to understand

The life cycle of magnetars.

We think that they're very young

But how young is still uncertain.

In addition to magnetars

Satellites and ground-based observatories

Have been picking up other violent things in space.

Scientists have now confirmed

The existence of a phantom-like force

That's so strong

That it might very well be the most vicious
phenomenon in the Universe.

Stealthy villains haunt each and every galaxy.

One particular beast tears up anything in its path

And gobbles it down like a cocktail hors d'oeuvre.

It's one of the most bizarre and destructive phenomenon

In the Universe

A black hole.

I think a black hole

Is the place which is more violent than
anywhere else in our Universe.

It's like going over the edge

And you can't get back.

It's fatal attraction, I suppose.

A black hole is a region of space

Where the pull of gravity is so immense

That nothing can escape it not even light.

Astrophysicist and triathlete

Feryal Ozel

Is attempting to unlock

The mysteries surrounding
this elusive cosmic force.

In a black hole

The gravity is so strong

That no other force can compete with it

So everything collapses to a single point.

Ozel says

Whatever has a close encounter
with a black hole

Will fall victim to its relentless
tidal force of gravity.

Imagine you're swimming in a pool

And there is no current

You can go whichever direction you want.

Now, imagine, you're taken out of this pool

And you're in a river.

Imagine a current that is much,
much, much stronger

That the only direction that you could go

Would be with this current.

The space around a black hole
acts like this wild river.

You could never fight this enormous
drag that you feel.

As an object approaches the
edge of a black hole

Called the "event horizon,"

It reaches the point of no return.

As you come closer and closer
to this event horizon

You would already be approaching

This extremely fast motion of space under you

And your only future direction
is now into the black hole.

The idea of the black hole

As a hole sometimes can be a little bit confusing.

What it really is

In some sense

It's a place from which you can't return

Or at least, not in the form in
which you went in.

Black holes are difficult to detect

Because as the name suggests

You cannot see one by itself because it's black.

But scientists

Have spotted a black hole

When its gravity affects something else in space

Such as a passing star.

A completely isolated black hole
would not be visible.

What we really see from a black hole

Is actually the hot material that's swirling around it

And that's being sucked into it.

So, in the neighborhood of these
powerful black holes

You'll get a lot of radiation

Resulting from the black hole

Pulling in material - And stretching it - And twisting it

As it's falling in black holes

Black holes consuming anything in close range

And there are billions upon billions
of them prowling the Universe.

Astrophysicist Andrea Ghez

Is one of the world's leading black hole hunters.

Black holes are not picky eaters.

They'll dine on whatever get nearby

So they will happily eat gas

They will happily consume a star or a planet.

When a black hole dines on a star

It does so first by tearing it apart.

And you might think of silly putty
being stretched out

And then it just streams on in sort of like water

Going down a drain.

It's completely pulverized.

Black holes are produced, we believe

By the collapse of the core of a massive star

Something like 25 or 30 times the mass
of the Sun or more.

When it comes to the end of its lifetime

A massive star burns its core

All the way past helium, carbon, nitrogen, oxygen

All the way to iron which has no
more nuclear fuel.

And when that iron core builds up
to a certain mass

There comes a point where it can
no longer support itself

And the core will collapse

All the way to a black hole

Producing at the same time a supernova.

The supernova sends out explosive
amounts of energy

So anything in its vicinity will get obliterated.

Then, the remnants of the explosion

fall into a newly formed black hole.

And it seems

The key to the black holes' allure is gravity.

Gravity will pull things around

Just like the Sun's gravity pulls
the planets around.

In fact

Stars will happily orbit the black hole
for most of its life

And won't actually be sucked in.

These stars are actually safe

From the fatal attraction of the black hole

But if you do venture too close

Like extremely close to the edge

Then you do get sucked in.

Scientists believe there are

Millions of wayward black holes throughout
our galaxy, the milky way.

And because we can't readily see them

One could be right next door.

So how close does something have to be

To get sucked into a black hole?

Too close to a black hole is about the distance

Between the sun and the earth

But that is certainly too close.

For future space travelers,
death by a black hole

Would be a violent way to go.

The method by which a black hole could kill you

Depends on how big the black hole is.

They come in two categories.

Most of them are the stellar-mass black holes

Which are five to 30 times the mass of our sun.

If the black hole is stellar-sized

Then the tidal forces near the black hole
is strong enough

That it will tear you apart tidily

Even well outside the event horizon.

If you wanted to fall into a black hole

You certainly wouldn't want to fall into one of those.

It will spaghettify you.

But in addition to the stellar-sized black holes

There are others that are mammoth

Millions to a billion times the mass of the sun.

And now, scientists believe

That these monsters hold center court
in every galaxy including our own.

Black holes

They're one

Of the most mysterious and potentially
dangerous oddities in space.

A black hole has a ravenous appetite.

It sucks in everything in its path

And spits out what it doesn't devour.

And now, scientists have discovered

There are supermassive black holes

Which are millions of times bigger
than their stellar mass cousins.

And evidence suggests

That supermassive black holes
were born after the big bang

When the Universe was first created.

The leading idea is that they would have formed

Just like the stellar black holes from the collapse

Of the core of a massive star.

But then they grew by feeding grossly

From the gas from other galaxies
which collided with them.

Scientists have discovered

That these black ogres

Wield their power in the center of galaxies.

The supermassive black holes are
at the center of the galaxy

Most likely because

They are the most massive object within the galaxy.

Massive objects tend to sink to the middle

So you'll always find them at
the center of a galaxy.

For a long time, scientists didn't think

A supermassive black hole existed in
our neck of the Universe

The milky way.

But in 1995

Astrophysicist Andrea Ghez

Set out to prove one exists.

We've done an experiment over the last 10 years

To ask the question

is there a supermassive black hole
at the center of our galaxy

And the way we did this experiment

Is to use the motions of stars at
the center of our galaxy

To test whether or not there's a large amount of mass

Inside a very small volume.

And that's the proof of a black hole.

At the Keck Observatory in Hawaii

Which houses one of the largest telescopes in the world

Ghez began using

A groundbreaking technology called "adaptive optics"

Which brings into focus far away objects.

So this is without adaptive optics.

This is what you would see.

In this big square, there's nothing.

We turn adaptive optics on

And you see the stars.

This region contains the stars

That provide the keys to our experiment.

So we wanna watch how these stars move.

Ghez noticed that there was a large cluster of stars

Orbiting around an invisible object
at the center of our galaxy

And they were moving at an unusually rapid rate.

So we can actually see these stars

That are really close to the center

And we can watch them go around.

Those stars go around the black hole

Just the way the planets orbit the Sun.

The orbits tell us

Where the black hole is

So it's located right where the star is.

That's the center of our galaxy.

And the details

Of exactly how fast these stars are going around

And how tight the orbits are

Tells us the mass of the black hole

Which we think today

Is four million times the mass of our Sun.

For Ghez

Confirming that a supermassive black hole indeed exists

At the heart of our galaxy

Was like summiting Mount Everest.

It was incredibly exciting to discover

The supermassive black hole at the center of our galaxy

Simply because it was a question we
had set out to address.

The question, "is there a supermassive black hole?"

And we could design an experiment
that actually got at it.

Astrophysicist Andrew Hamilton says

"death by a supermassive black hole

would be much different than by
a smaller stellar mass relative.

If you wanna go and be a tourist

And have the ultimate experience
of falling inside a black hole

And finding out what's really there

Go visit a supermassive black hole

Much better idea , Unlike a stellar black hole

Which would rip you to shreds,
before entering its deadly vortex

A space explorer could actually experience

Free falling inside a supermassive black hole.

Inside of a supermassive black hole

it turns out that even though
the black hole is more massive

It's also much larger in size.

And that means

That the type of forces are weak enough

That you could pass through the event horizon

And fall deep inside the black hole

Without being tidily torn apart.

But, deep down inside the black hole

The centrifugal force of the rotation
of the black hole

Provides effectively a repulsion.

If there's any matter at all inside it

Then stuff that's falling in

Will tend to collide with stuff
that's trying to get out.

And the result of that collision of energies

Is an unimaginably chaotic maelstrom
of super hot dense plasma.

And in that case

Your fate is that it can roast you.

So how close would space travelers
have to be to get sucked

Into a supermassive black hole in the
center of a galaxy?

For a supermassive black hole

You would have to be about a million to a billion miles

From the black hole to feel its influence.

Over the years

The Chandra x-ray Observatory

Has caught our galaxy's

Supermassive black hole nibbling on cosmic matter

Not bingeing like other supermassive black holes.

Our black hole is, today, inactive,
compared to other black holes.

Our galaxy has very little gas at the center

And so, there's nothing really for
the black hole to feed on.

It's not eating very much.

It's going on a bit of starvation diet.

Our galaxy's supermassive black hole
appears to be fasting.

This is partly due to the fact

That as a galaxy ages

Less and less matter is present for it to gorge on.

But, in the future

It might be quite a bit more active

If it ever gets a fresh supply of gas
at its center to feed off of

One way to rejuvenate our
supermassive black hole's appetite

Is to collide with another galaxy.

Sound implausible?

Two million light-years away

Our closest neighbor, the Andromeda galaxy

Is charging toward us at almost 75 miles per second

Or 270,000 miles per hour.

In the future

Scientists predict the two galaxies will collide

And upon impact

The larger galaxy may engage in

one of the most primitive acts
known in the Universe.

It's one of the most barbaric rituals in space

A larger galaxy eats a smaller one.

The scenario isn't a science fiction writer's fantasy

It's a cosmic reality.

It's called "galactic cannibalism."

The ghastly event can occur on the celestial highway

When two galaxies have a head-on collision

Both eventually melt together in a less
than harmonious merger.

If you're a galaxy, it's very violent.

You're torn to shreds.

Joshua Barnes studies galaxy mergers.

Acting like a crime scene investigator

He admits his research is a bit like
inspecting a car crash.

Imagine that you come across
the scene of a car crash

Two wrecked vehicles but no witnesses

Nobody to tell you what happened

All you have is the physical evidence.

That's basically what we have to do

When we study colliding galaxies.

So there are no witnesses to a galactic collision.

All that you have is the present
state of the wreckage.

So you have to conduct a sort of
forensic investigation

To try and figure out

what happened on the basis of
what you have today.

If they collided head on , You would know

Because the fronts were squashed up.

And if they, say, side-swiped each other

Which is actually more likely in galactic collisions

That would leave you a completely
different pattern of wreckage

And you could interpret that.

So what causes galaxy mergers?

It's gravity.

Everything in the universe is falling
freely through space

And when you've got two large
objects like galaxies

Their mutual gravity pulls them together

So they fall into each other.

So it's really just the force of gravity
pulling things around.

The galaxies that we're seeing colliding today

Most of them have been bound
and destined to collide

For upwards of 10--15 billion years

And they're only now just making
it to that first collision.

Our own galaxy, the Milky Way

Is moving toward our neighbor, Andromeda.

Both galaxies are spiral in shape

But andromeda is about twice as massive
with a supermassive black hole

The mass of 30 million suns.

It'll look a lot like a dance.

When you see the two galaxies
come close together

So they kind of dance around each other

Getting closer and closer,
moving faster and faster

Before they finally come together.

But at the point of impact,

These galactic dancers will do
more than pirouette.

Each one has a spiral disc of stars

And then surrounding that,

A halo of dark matter, invisible material

That we can detect by its gravitational field.

These two dark halos, which are much larger

Will overlap as the galaxies pass by.

Eventually, as the two galaxies spiral around
each other closer and closer

You can no longer distinguish them
as separate systems

And finally, the nuclei merge.

When Andromeda and the Milky Way collide

That's going

To be the biggest collision that
the Milky Way has seen

Something like five billion years' time.

The good news is that we, the solar system

Will have a grandstand view.

What will happen is the two galaxies

Their spiral discs

Are gonna get tidily torn apart
into fantastical shapes.

When the discs start to get close to each other

They'll throw off long streamers of stars

So-called "tidal tails."

And what happens to the Sun and the solar system

Should we still be around

It really is hard to predict.

We could get lucky and be on one of those tidal tails

And get a sort of bird's eye view of
the whole process as we fly out

Or we could get thrown into an orbit

Plunging towards the center of
the merging galaxies.

There's basically no way to say.

During the merger

If our solar system moves through the suburbs
or the edges of Andromeda

We might not notice anything.

On the other hand

Countless stars and space material

Could be propelled towards the planets

Potentially disrupting their orbits around the sun.

Moreover, the entire galaxy could
face cosmic upheaval.

We could have consequences

Which would nonetheless be dangerous.

First of all, we could have

A lot of star formations as
a consequence of the merger.

Currently, both the Milky Way
and Andromeda galaxy

Have plenty of interstellar gas

The raw material from which stars are born.

Now, that would mean

A lot more evolved stars, supernova
going off in our vicinity

And that could create shockwaves, blast waves

Or bursts of cosmic rays

Which would have nasty consequences.

After the merger

The fate of our solar system is uncertain

As the supermassive black holes of
Andromeda and the Milky Way

Vie for power in the newly jumbled galaxy.

When they merge, they're gonna form a new galaxy

And these two supermassive black holes

Will gradually spiral into the middle
of the new galaxy.

They will be a binary black hole for a short time.

And these black holes will start to swallow gas

As the collision stirs things up

Gas will fall into those black holes.

They're gonna turn on.

They're gonna start emitting radiation.

But the potential for fireworks, possibly
for fueling the black holes

At the centers of the galaxies

Matter falling into them, possibilities
like that do exist

And then the only safe place to watch the process

Would be on one of those tidal tails

Riding out and escaping the collision.

Some scientists think that

Andromeda's larger supermassive black hole

Will eventually consume the Milky Way's.

The two black holes will spiral in the center

And become a binary black hole

And ultimately, will merge with one another

To become yet an even bigger
supermassive black hole.

So, a small galaxy colliding with a large galaxy

Is likely to be dominated by the larger galaxy.

It'll essentially have most of its material

Absorbed by that galaxy and
becomes subsumed into it.

Scientists believe galaxy mergers

Are a way of life in the Universe.

Modern galaxies, including the Milky Way

Have grown larger by cannibalizing smaller galaxies.

Every galaxy that we see

Has probably been through many collisions.

The Milky Way has a central bulge of stars,

Which are, probably, the relic of a previous collision.

Most scientists agree that

the much anticipated merger between
the Milky Way and Andromeda

Won't happen for at least three billion years.

But there may be more immediate dangers in space.

In cosmic neighborhoods,
millions of light-years away

There are hyperactive galaxies

That have become the big bullies on the block.

At the heart of some galaxies lives a cosmic monster.

It transforms a run-of-the-mill galaxy into

one of the brightest and deadliest in space.

Quasars are peculiar objects.

Each powered by a supermassive black hole

That continually swallows large amounts of matter

10 to 20 stars every year.

At the core of these objects
lives a very large black hole.

And the role of that black hole

Is to actually generate a huge amount of energy.

Quasars are the most energy-efficient
mechanisms in the cosmos

They give off more power than
a hundred normal galaxies.

And they're 10 trillion times
brighter than our Sun.

So how are quasars created in the Universe?

There's a fairly good connection

Between the last stages of a galactic merger

And the so-called "quasar phenomenon."

If that really happens in the case of
the Milky Way and Andromeda

We could have

For a period of some tens, even
a hundred million years

A quasar active in the center
of the merged galaxies.

And a quasar puts out about a hundred times

As much energy as a typical galaxy.

And if we were actually thrown into an orbit

Which took us towards the center of the galaxy

We could get very close to that quasar

And really get scorched.

The word "quasar" stands for
"quasistellar radio source,"

Which means star-like emitters of radio waves.

The word was coined

When the quasar phenomena was still a mystery.

Now, we know they're not star-like at all.

In addition to emitting radio waves and visible light

Quasars also give off ultraviolet rays

Infrared waves, x-rays, and gamma rays

All deadlylf, something or someone gets too close.

A quasar is a supermassive black hole
at large distance

but it's is active, it's powerful, it's emitting light

And we can observe it in many wave bands.

Quasars were first discovered in the 1960s

But as radio telescope imaging got better

Astronomers discovered that some of those quasars

Also have powerful jets beaming out of them.

These particular quasars are called "blazars"

Probably some of the most violent
phenomena in the Universe.

Blazars are powered by black holes just like quasars.

But they're somewhat different in that all their energy

Is being focused

Or a large amount of their energy is being focused into

jets which are streaming out.

A blazar's aggressive plasma jets produce

radiation in the form of radio waves

All the way through the spectrum

Up to high-energy gamma rays.

Astrophysicist Glenn Piner

Had been investigating the physical conditions

At the centers of these exotic galaxies.

We can use this fountain to visualize
the geometry of a blazar.

If that circular base of the fountain

Represents the accretion disc

Then the jet of water that's coming up

Represents the jet of plasma
coming out from the blazar.

And if the earth is sitting up in the
direction that water is going

Then we would see this object as a blazar.

For an astronomer, it's like
looking down a fire hose.

It really gets you in the eye to see this bright

Blazing thing that we call a "blazar."

These blazar jets move exceptionally fast.

The fastest observed move at
99.9 percent the speed of light.

If you were to take a small object

Like this bowling ball

And you wanted to accelerate it

Up to 99.9 percent of the speed of light,

You would have to give this bowling ball

All the energy produced in the world

For an entire week to accelerate it to that speed.

And in these blazars

We're accelerating not just small
objects like bowling balls

But large masses of the mass of
the planet jupiter or larger

To those speeds

So they're being given incredible amounts of energy

By this efficient engine.

Blazars pose unimaginable consequences

To cosmic objects that get too
close to its deadly jet.

If there was a planet relatively close

A few light-years from the actual jet

The radiation on that planet

Could be millions of times what
it gets from the star.

It would be continually exposed
to high levels of radiation.

So I don't think

We wanna look for life on a planet

That would be orbiting a star,
that's in a blazar jet.

Scientists link radio telescopes all over the world

To achieve the magnification needed
to zoom in on a blazar jet.

So to give you an analogy for
what kind of magnification

That would be magnification
sufficient to read a newspaper

That someone was holding in
New York from Los Angeles.

We'd love to look as close to the
central black hole as possible

So we could actually figure out how nature

Is accelerating these jets

And getting them up to such high speeds.

And we'd also like to know

What it is actually that the jets are made of

Because it turns out that's something

That's currently not known.

Until more is known about blazars

Astronomers will keep a neighborhood
watch for them

As well as all the other dangerous places

In our uncontrollable Universe.

Definitely

There are violent events
going on in the Universe

Much, much more energy than we
can even imagine on Earth.

There are trillions of suns shining all at once.

Those are the kinds of energies
that we're talking about.

But in that case the fact that we
are far away from them

Helps the survival of our species.

If we're actually travelling through space

Then, definitely

We will have to be worrying about these events.