Original subtitles

SUB BY : DENI AUROR@ https://aurorarental.blogspot.com/

In space, no one can hear you scream,

which is a shame,

because the universe is more violent

and far scarier

than anything you can imagine.

Superdense neutron stars collide.

Newborn planets smash each other in demolition derbies.

And supermassive black holes

blast out swarms of deadly cosmic rays.

There are stars exploding, galaxies colliding...

...nebulae where there's all kinds of radiation

and shock waves.

This is the ultimate guide

to the worst places in the universe.

Captions paid for by discovery communications

Let's say you've got a taste for adventure,

a risk-taker extraordinaire,

used to laughing at danger and death.

Want to take on the worst the universe can throw at you?

Well, you better think twice, because the cosmos has it all ...

havens for life...

And lethal hellholes.

Bullock: Our universe is both benevolent and violent.

There are little oasis pockets,

where things are very nice and calm

and really good for life, like right around here.

But there are definitely places and times

where things get violent and rough.

But you don't have to venture to the wrong side of the tracks

to encounter some of the universe's scariest locations.

Some are right here in the neighborhood.

Take betelgeuse,

hidden amidst the beautiful Orion constellation,

a red star 640 light-years away from earth

and ready to die.

Now, betelgeuse is a huge, red, supergiant star.

And it even looks kind of angry and red

hanging up there in the sky.

It's so big that if you put it in our solar system,

it would expand all the way out to the planet Jupiter.

It's gigantic.

When massive stars, like betelgeuse, die,

they go out with an epic bang.

Now, this star is just on the edge of going supernova.

And when it does, we're in for quite a show.

Betelgeuse is running out of gas.

The nuclear fire at its heart fights a constant battle

against the crushing gravity of its enormous mass.

Once the gas is gone, you'd better stand back.

No one can predict exactly when, but soon,

the star will begin to collapse.

Imagine you're near the surface of this star

just before it goes out, just before it goes supernova.

You're gonna see the surface of that star

just recede away from you incredibly rapidly,

much like if you were at the beach

and you saw the water just recede away

from you really rapidly.

You know something bad is coming.

The collapsing outer layers pummel the core,

making it denser and denser.

The core compresses as more of the star falls in.

All that gas has to go somewhere,

so it bounces with an explosive force

we can hardly imagine.

When betelgeuse goes supernova,

we are talking about an epic catastrophe.

An entire star is exploding.

It's hard to describe just how much energy that is.

Imagine all the energy the sun puts out every second.

Multiply that times 31 million seconds in a year.

Multiply that by 10 billion years

in the sun's lifetime.

That is how much energy a supernova puts out.

The energy unleashed is a shock wave

of light, heat, and superheated gas...

...racing out at thousands of miles a second,

destroying everything around it.

Life on any planet orbiting this exploding star

would be completely eliminated.

You certainly wouldn't want to book a cruise

to betelgeuse anytime soon...

...or, for that matter, after it's gone supernova.

Because when it finally dies,

it might leave behind a nasty surprise,

one of the most extreme objects in the universe ...

a neutron star.

Neutron stars are kind of like vampire zombies.

They are the cores of massive stars that have died.

But now these neutron stars have their own gruesome lives.

And you don't want to get anywhere near this thing.

Trillions and trillions of tons of matter

are compressed into a sphere roughly the size of Manhattan.

A neutron star is the densest body

we know of in astrophysics, besides a black hole.

If you somehow had

a little stone-sized piece of neutron star matter,

it would weigh 100 million metric tons.

And it would immediately fall right through your hand.

Because the neutron star is so dense,

it generates an intense gravitational field.

It is really hard to exaggerate

how dramatic and dangerous a neutron star is.

The gravity is so intense,

it would actually bend light around it.

You would see all these kind of weird, shimmering effects.

Dazzling, but deadly.

No astronaut will ever be able to approach a neutron star.

But if you're an armchair traveler

and want to find out what would happen,

let's send a galactic crash-test dummy.

Let's call him Chuck.

Crash-test dummies are a species

that are completely devoted to ensuring human safety.

And they sacrifice themselves to do it.

Everything he encounters is gonna be a pretty rough ride.

Better him than me.

As Chuck nears the neutron star,

its gravitational grip is doing some very bad things.

The gravity's pulling on him so hard

that he is accelerating all the way down to the surface.

He'll be moving at very roughly one-half to two-thirds

of the speed of light.

The neutron star's gravity

is 200 billion times stronger than on earth.

Around 150 miles above the surface,

it starts to pull on Chuck's limbs

in a distinctly unpleasant way.

As you get closer and closer to a neutron star,

we were told to think that it would be

this elegant spaghettification,

where you would get longer, like a piece of spaghetti,

but in reality, you're gonna get ripped to shreds.

Think about what you're really gonna experience.

Think about, first,

all your joints dislocated in your body...

...your skin getting ripped off of your body,

your bones being pulled apart, your organs being pulled apart.

Within the blink of an eye, Chuck is reduced

to a thin stream of atoms hurtling towards the star.

Those atoms will eventually fall down onto the neutron star.

And, unfortunately, the violence doesn't stop there.

What's left of Chuck hits the surface,

triggering a huge burst of energy.

So, we're talking about 100,000 miles per second.

That's an impact.

He's gonna hit so hard

that the amount of energy released is just huge.

It would completely dwarf the entire arsenal

of nuclear weapons on our planet.

Anything and anyone venturing too close to a neutron star

is destined for this catastrophic end.

Thompson: A neutron star is one of the most dangerous objects

you could meet in any phase of their existence.

If you're meeting a neutron star right when it's born,

that means you're very near a supernova,

and that means death.

If you meet a neutron star

after the supernova has gone off, that would be death.

And then if you were lucky enough, or unlucky enough,

to go falling onto a neutron star,

you'd be destroyed very rapidly and torn apart.

If I had one piece of advice about neutron stars

for future space travelers,

it would be, "no. No! Stay away."

So you really don't want to be anywhere near one neutron star.

But two neutron stars colliding?

That creates one of the strangest

and most lethal particles in the universe.

A neutron star is definitely not the place to visit...

Unless you want to be torn to oblivion.

But two neutron stars can be even worse,

creating something so weird, so deadly,

it could potentially transform the entire universe

into a zombie.

June 2013.

NASA's swift satellite spotted

a short burst of energy from a nearby galaxy.

It was evidence that something incredibly energetic and violent

had taken place.

It was a collision between two neutron stars.

When two neutron stars merge,

the amount of energy in this explosion is crushing.

There's almost no way to describe it.

The explosion released more energy

than the sun will in its entire lifetime.

These are the biggest explosions in the universe

since the big bang itself.

But there may be more than just energy released

in the explosion.

It's possible that neutron star collisions

release something really, really weird ...

a new theoretical particle called a strangelet.

Strangelets are called this

because they're made up of a type of matter

that nothing else around you is.

All the matter around you is made up of neutrons and protons.

And these are made up of two types of quarks.

One, we call the up. The other, we call the down.

Strangelets have a different type of quark in them,

and this is called the strange quark.

Strange quarks can come together to make bigger particles.

But it's not like normal matter.

It's not like neutrons and protons that make up us.

This would form a weird conglomerate

called a strangelet.

To understand strangelets,

scientists use a theory called the strange matter hypothesis.

It states that strangelets could be a stable form of matter

and that under certain extreme conditions,

they could form.

The inside of a neutron star

might be an interesting place to look for strange matter.

If strangelets could exist,

that might be one place where they would.

The pressures inside the core of a neutron star

are off the charts ...

high enough to potentially form strangelets.

These strangelets come in two forms ...

positive and negatively charged.

The positive kind is fine, but the negative ones ...

well, you'd better watch out.

You can think of strangelets as being these subatomic zombies.

Once they bite you, you're a strangelet, too.

And what'll happen is that the nuclei in a normal matter

will be converted to strange matter.

If negatively charged strangelets are released

during neutron star collisions,

they could set off a chain reaction,

zombifying any normal matter they touch.

So you have this runaway reaction

of normal matter being converted to strange matter

and giving off energy as it does so.

It's a little bit like the old Sci-Fi movie "the blob."

Everything the blob touches just basically turns into more blob.

Strangelets basically will consume the matter around them.

And you get a runaway cascade effect

that doesn't end well.

When a strangelet hits Chuck,

it transforms him into a ticking time bomb.

So, everything that was Chuck in terms of normal matter

would quickly convert into strange matter,

not only changing his identity, but also, in the process,

releasing tremendous amounts of energy.

Once an area around the size of his fingernail

is converted into strange matter...

...he explodes,

blasting strangelet particles through space.

Once you start to convert

a small amount of matter into strange matter,

the energy released will propel more strange particles out

to find yet more matter.

And the whole process will just get worse

and worse and worse.

If strangelet particles were to hit a planet, like earth,

the results would be catastrophic.

So, imagine this strangelet strikes our atmosphere.

When it strikes those atoms,

they're gonna be converted into strange matter.

And that strange matter is gonna generate more strange matter.

So you're gonna have a strange bubble

emanating from this location,

all the while giving out more and more energy,

which goes into creating more strangelets,

until the entire planet is consumed

in the strangelet explosion.

The debris left over shoots out into space,

a swarm of newly formed strangelet zombies,

ready to destroy everything they touch.

One planet gets converted into strange matter,

then the next planet, then the star,

then the next star.

So, in this way, you could have entire strange galaxies.

Ultimately, strangelets could transform the entire universe.

So...how are we still here?

We've witnessed neutron star collisions.

So where are the strangelets?

On the one hand, we're not made of strange stuff.

Maybe it's not something that really exists or could happen.

But on the other hand, space is really big.

It would take millions of years for any strange matter particle

coming from the nearby largest galaxy to reach us

if it's moving at the speed of light.

So it could be happening, and it just hasn't made it here yet.

Perhaps there are colliding neutron stars

far across the cosmos, releasing strangelets.

Only the future will tell.

But neutron stars are not the only source

of lethal particles in the universe.

There are billions of them out there.

And there's one in the heart of our galaxy.

The milky way ... our home galaxy.

It's over 100,000 light-years across

and home to extraordinary nebulas

and hundreds of billions of stars.

These stars orbit the center of the galaxy,

circling the supermassive black hole

called sagittarius a-star.

They look stunning,

but their glow is pure lethality...

...adding the heart of our galaxy

to our itinerary of worst places in the universe.

The biggest factories of radiation in the universe

are stars.

They're actually burning through these nuclear reactions.

And that creates the light that we're familiar with.

The bigger and more massive the star is, the hotter it burns

and the more dangerous the radiation.

The galactic core is home to the most active stars of all.

And should we visit,

we'd be blasted by a blizzard of intense radioactivity.

The word "radiation" sounds very dangerous, very bad.

But when you think about the definition,

it's all around us.

Radiation is really any form of light.

So right now, I'm giving off heat.

I'm a warm thing. That's radiation.

It's just that some forms of radiation

are very benign and good for matter, and some aren't.

Some has lower energy. Some has higher energy.

And when you start getting to higher and higher energies,

that can get more and more dangerous

because as your cells absorb that energy, it can damage them.

This type of radiation is called electromagnetic radiation.

And the most powerful x-rays and gamma rays are so strong,

they can cause radiation sickness

and, in some cases, death.

There's another kind of radiation,

called cosmic rays ...

tiny, subatomic particles

that move at near the speed of light.

New research suggests

the most energetic cosmic rays don't come from stars.

They come from supermassive black holes.

When people think about black holes,

the whole idea is that they're dark.

They actually absorb light.

But what might surprise you

is that as stuff falls into a black hole,

it gets hotter and hotter.

It even gets directed into extremely high-energy jets

above the black hole.

As this material falls into the black hole,

it forms into this disk.

And a tremendous wind is blown away

because this disk is so hot.

It's blasting out subatomic particles.

So this isn't matter from inside the black hole.

But as stuff falls in,

it becomes the most intense radiation in the universe.

Supermassive black holes

act like turbocharged particle accelerators.

They superheat and blast particles

in jets from their poles.

Isler: These jets are extremely powerful.

They are so powerful

that they are able to accelerate particles

to 99.99% of the speed of light.

That's really fast.

It's perilously close to the upper limit

to which things can be accelerated.

These accelerated particles are cosmic rays.

Cosmic rays are the most energetic particles

we know of in the universe.

They might even just be a single proton.

But these have been accelerated to such high speeds

that one of these can pack the wallop

of a 100-mile-an-hour fastball.

These are like tiny cosmic bullets.

And if you get hit by one,

it can actually blow apart the DNA in your cell

or blow apart the cell itself.

Our sun's heliosphere

deflects most of the cosmic rays coming our way.

But outside this magnetic protective bubble,

we'd be vulnerable.

Even a spaceship might not protect us.

To protect yourself from particle radiation,

you have to be careful.

You might think, "well, I'll just use a big sheet of lead,

and that'll do it."

And it turns out that makes things worse.

Planetary scientist Dan durda explains.

He staples balloons to a board to represent cells.

Durda: I feel a little bit like Frankenstein.

I'm assembling a body here, cell by cell.

A 1/2-inch-thick sheet of steel

represents the protective hull of the spacecraft.

A rifle bullet ... the cosmic ray.

Durda: I'm gonna fire this galactic cosmic ray

toward our solar system

and see what it does to our spacecraft.

As the bullet hits the metal,

it shatters into a hail of shrapnel

that spreads out, hitting the balloons.

It's the same with cosmic rays.

These little particles will hit the metal,

and they will basically free a bunch of electrons

from the atoms in the metal,

and those electrons will then shoot through you.

And so now, instead of getting hit by one particle,

you're being hit by a bazillion particles,

and that's bad.

Durda: So, if those were the cells of your body,

you'd be in severe trouble

because when this galactic cosmic ray

blasted through the wall of the spacecraft,

it spalled out of there, and at an atomic level,

it's not just the damage from that one cosmic ray

bursting one cell.

All of this atomic shrapnel blasted through many cells.

So these stand-ins for human cells

really represent the severe challenge

that future space travelers have out there in space.

How do you protect yourself

from these high-energy galactic cosmic rays?

You don't want that happening to the DNA,

to the cells in your body.

The center of the galaxy is off-limits ...

a vacation no-go area.

We're lucky to live far away from the center

and protected by our sun.

It may seem kind of unfortunate

that we're sort of in the suburbs of the galaxy.

We're almost 30,000 light-years away from the center.

But this may be the best place for life.

Next in our tour

of the worst places to visit in the universe ...

a cosmic nursery,

the birthplace of stars and planets.

But you won't be humming any lullabies here,

because it's also a shotgun loaded with cosmic buckshot.

Now we witness the birth of a planetary system,

a beautifully orchestrated family of planets

somehow coming together out of gas and dust.

Who wouldn't want to witness such a thing up-close?

You, if you don't want to be

in one of the most deadly places in the universe,

because, as it turns out, planet birth can be lethal.

This is lkca 15.

It's a star 450 light-years away,

similar in mass to our sun.

A protoplanetary disk of dust and gas surrounds it.

And in it, new planets are being born.

When planets are first forming,

there's a disk of material around the star

when it's very young.

And the planets basically form from all this debris.

Stuff hits and sticks together.

And it grows bigger and bigger and bigger,

and then its gravity draws material in.

Planet formation is like a demolition derby.

There are a lot of similarities.

In a derby, the cars are racing around a track,

going around in circles at different speeds.

Well, it's the same thing with planets.

The material is orbiting the sun. It's going around.

And they're all going at different speeds,

at different angles, different trajectories.

Sometimes this material collides.

And you get a bigger object left over.

And that's how planets grow. It's how they form.

It looks beautiful from afar, but venture too close,

and you'll be surrounded by speeding material.

The material ... the dust, the grains of sand,

even the bigger rocks ...

are moving at orbital speeds around this protostar.

So we're talking about 10, 15, 20 miles per second.

You might think that the large rocks

are the most dangerous.

But in space, that's not necessarily the case.

The bigger rocks can be seen, can be tracked.

Things this big can be tracked in space.

But anything that's about this big is hard to find in space.

You don't know it's coming.

So while we're all fearing the big rock,

if you're out in space, you better watch out

for the small rock that's moving fast.

If a bb-sized rock going at 40,000 miles an hour

hits our crash-test dummy,

it's gonna cut right through him.

You know, there are rules in baseball

that a batter has to wear a helmet

because there's a baseball moving at him

at 100 miles an hour,

and if that hits him in the head, it could kill him.

Now imagine that that baseball

is being thrown 1,000 times faster, right?

That would put a hole right through a batter's head.

It wouldn't even slow down.

That's how dangerous these things are.

The space around the star

is jammed full of every size of debris.

Thompson: Rocks are gonna be spinning around,

ricocheting off each other, colliding and sticking.

It's a horrible, hostile environment for Chuck.

He's gonna be hit often and hard.

You're just gonna see him get blown to bits.

Putting Chuck into a protoplanetary disk like that

is like, basically, sticking a shotgun in front of him

and pulling the trigger.

There's just a huge amount of material

moving at tremendous speeds,

and it would hit him and just rip him to pieces.

So, what if you decide to get a little peace

and head to one of the quietest places in the universe,

far from dangerous debris?

Well, looks can be deceptive.

Because visiting even one of the emptiest places in the cosmos

can be a nightmare,

where something thinner than an atom

and light-years long can cut you to ribbons.

When we look out at the heavens,

we can see billions of galaxies and trillions of stars.

They generally look evenly spaced out.

But in 2015, scientists spotted something strange.

But every now and then, we find something we can't explain.

There is a giant area

that's colder and emptier than it possibly could be.

There's not very much matter in there.

There's not that many galaxies there.

There's not much energy in there.

And we call these voids, and some of them are quite large.

They're called supervoids.

One of these supervoids is 1.8 billion light-years across,

making it the largest individual structure ever identified.

This void has 20% less matter,

10,000 less galaxies than would be expected.

That equates to around 1,000 trillion stars ...

all missing.

We are not completely sure how the supervoid formed.

We do know the layout of the galaxies was determined

at the very start of the universe.

So it makes sense to look at the big bang.

Or, more specifically,

a baby picture of the infant universe,

when it was just 380,000 years old.

It's a snapshot of the cosmic microwave background,

the pattern of heat left over from the big bang.

When you look at maps of the microwave background,

we see different colors ... red and blue.

Those aren't real colors.

They're artificial colors that we put down

to indicate where the temperature

is a little hotter than the average

and a little colder than the average,

not by much ... merely one part in 10,000.

The regions that appear a tiny bit warmer

had slightly more material.

They would go on to form galaxies

and all of the structures

we observe in the universe today.

The colder regions had less matter,

so they didn't form complex structures.

It's thought that some of these less dense areas

ended up forming the supervoids.

These voids may be quiet,

but even they could be home to some really weird phenomena ...

something like a cosmic string.

Now, these are completely theoretical.

We don't know if they exist.

But they could have been created

when the universe was very young.

It's thought when the superhot, superdense, infant universe

started to cool,

it created cracks in the fabric of time and space ...

cracks that are thin and dense.

These cosmic strings are incredibly weird.

They're one-dimensional, and they're incredibly heavy.

They are thought to be thinner than a proton

but incredibly dense.

Just 10 miles of a cosmic string would weigh more than the earth.

And so imagine all of this mass and energy

in a one-dimensional object.

This is like the sharpest, most powerful knife

the universe has.

So, what would happen if our crash-test dummy, Chuck,

encounters a cosmic string?

A cosmic string is like a cosmic lightsaber.

It's a one-dimensional path of pure energy

that would slice him right in two.

Cosmic strings do strange things

to the space they hide in.

They twist and distort time and space.

After cutting Chuck in half,

the string slams his head and feet together.

When Chuck encounters this superpowerful cosmic string,

he encounters perhaps the opposite of spaghettification.

He gets pancake-ified.

The supervoid is large, cold, and lacking matter.

Our final location is just the opposite.

It's compact, hot, violent, and crammed with stuff.

It's also the site of the most violent battle

in the history of the cosmos ...

the battle to create everything.

Our number-one worst place in the universe

is the most extreme of all ...

the birth of time and space, the big bang.

The universe is full of wonders.

And they were all set in motion

during the first second of existence.

But this nearly didn't happen.

First, matter had to win a battle for survival.

When the universe was first born,

it occupied the space that we call the primordial fireball.

Picture the scene ...

intense heat...

Intense pressure.

It would be an awful place to visit.

You'd be crushed, incinerated, and blasted by radiation.

But there's worse ...

a battle between particles of matter

that will determine the future of the universe.

Einstein's equation "e" equals mc squared

tells us that energy can become matter.

And in this early universe, this turns out to be the case.

Primitive particles of matter spark into existence.

But there's a problem.

This matter comes in two forms ...

regular matter and antimatter.

We know what matter is. We see it all around us.

But what is antimatter?

Thompson: Antimatter is not as mysterious as most people think it is.

Antimatter is normal matter but with opposite charge.

So there are protons and there are antiprotons.

A proton is the nucleus of hydrogen.

And it's possible to have antiprotons.

And an antiproton has the opposite charge of a proton.

On its own, antimatter isn't dangerous.

But when it comes into contact with matter,

well, that's a whole different ballgame.

In the end, what happens is,

if you have matter and antimatter

and you bring them together, they will annihilate each other

and turn themselves into pure energy.

It's the quintessential example of "e" equals mc squared,

Einstein's famous equation.

You can take the mass of one particle

and the mass of another particle and you can combine them,

and since it's matter and antimatter,

they produce pure energy.

The infant universe was a battlefield

of matter and antimatter,

annihilating each other in a frenzy of obliteration.

Which raises a question ...

how is there a universe made of matter?

Why wasn't everything destroyed?

If there were equal amounts of matter and antimatter,

they would have annihilated in the early universe

'cause matter particles can annihilate

with antimatter particles.

And all we'd be left with is pure radiation.

What's amazing is that we live in a universe

which, as far as we can see, just has particles of matter.

In the early universe, there must have been

an imbalance between matter and antimatter.

The universe was born

with equal amounts of matter and antimatter.

But for every billion particles of antimatter,

you had a billion plus one particles of matter.

That tiny difference was enough to create the entire cosmos.

We know antimatter nearly wiped out matter.

So would we be wiped out

if a particle of antimatter hits us?

Antimatter is the stuff of science fiction

because, of course, it annihilates matter.

So people suddenly think that if a particle of antimatter

came in this room, what it would do

would ultimately annihilate a particle of matter.

But big deal. It's an elementary particle.

The amount of energy that'd be released

would be incredibly small.

So we're safe ...

if there's only a little antimatter.

But back in the early universe, it was a whole different story.

There was loads of the stuff.

And if Chuck wanders into a cloud of antimatter,

game over.

What would happen at the time,

if Chuck were immersed in that environment

or that much antimatter,

then ultimately every particle in his body

would interact with an antiparticle,

turning into pure radiation,

and Chuck would go out ... poof ... in a mass of light.

Chuck would turn into a light being.

We've taken a tour

of the absolute worst places to be...

And the worst things to see...

In the universe.

Cooper: There are so many things in our universe

that sound like science fiction,

but it's really based off of real science.

Everything out there can kill you.

Dust can kill you, stars exploding,

the heat from stars,

gravity from black holes, radiation.

All this stuff is very dangerous.

You can say, "hey, isn't it safer to stay on earth?"

But you know what ... ships are safe in the harbor,

but that's not what ships are for.

With all these dangers lurking in space,

I'm happy to be right here on earth.

That is, unless the aliens show up with their spaceship,

in which case, I'm out of here.

The irony of the dangerous places ...

we wouldn't be here without them.

Our universe only exists

because matter defeated antimatter

in the annihilation of the big bang.

And we only exist because a supernova blew up

and spread materials that built planets and us.

So the universe gives, and the universe takes.

Space may seem like a very scary place,

but then you have to consider that we wouldn't even be here

if it weren't for supernovae.

So although these things

seem outside the realm of our experience,

they really are just how the universe works.