a

What If You Fell Into a Black Hole?

how much do you know about black holes

what would happen if you fell into one

say one day you were exploring space

looking for a new planet for humans to

inhabit but came across a black hole and

decided why not check it out would you

have any chance of survival how would

you get out would there be a shortcut to

another universe this is what if and

here's what would happen if you fell

into a black hole

despite being black and a hole a black

hole is not a dark empty space in his

theory of relativity Einstein predicted

how black holes are formed when a

massive star dies it leaves a smaller

remnant core behind if the cores mass is

at least three times bigger than the

mass of our Sun gravity overwhelms all

other forces and turns the core into a

black hole but don't let its name fool

you a black hole isn't a hole at all but

rather a huge amount of matter packed

into a very small space think of the Sun

with its gravitational field 28 times

stronger than Earth's if you were to

walk on the Sun you'd be 28 times

heavier than you are on earth now

imagine squeezing four Suns into

something that's just 15 miles in

diameter the distance you can cover in a

30-minute Drive

what would the gravity be like there a

black hole's gravity is so strong that

even light can't get out that's why

you'll never see one but you can detect

it from the gamma-ray bursts to the hole

emits these bursts discovered by Stephen

Hawking now carry his name Hawking

radiation Stephen Hawking himself

believed that black holes can be

passages to another universe so if you

were to fall into one would you find

yourself in an alternate dimension every

black hole has an event horizon the

point at which gravitational pull

becomes so strong you can't escape from

it

the point of no return if you found

yourself outside of that point you'd see

that stars are twisted around a perfect

circle of darkness as you start being

pulled toward a black hole you'd be

moving faster and faster accelerated by

the force of gravity that's the first

bad news for you brave space traveler

the gravitational force of a black hole

is very very strong if you fell feet

first your legs would be feeling a

stronger gravitational pull than your

head your body would be stretched apart

the most common black holes are called

stellar they can stretch about 9 miles

across and be as heavy as 20 Suns if you

happen to be pulled towards a stellar

black hole you'd be completely torn

apart before you even reach the event

horizon so make sure to choose a

supermassive one the one that's a

million times heavier than our Sun in

this case your body would remain

unharmed as you cross the event horizon

as the gravity would be pulling both

your feet and your head with almost the

same strength and if you're wondering

where to find one you don't have to look

too far there's one right at the center

of our Milky Way galaxy luckily it's a

hundred and sixty-five quadrillion miles

away from us and will suck in neither

the Sun nor the planets but don't pack

your suitcase just yet crossing the

event horizon is just the beginning of

the challenge there's a gravitational

singularity at the center of the black

hole where density becomes infinite

you'd be squashed into that center and

become one with the black hole you

wouldn't be able to tell anyone about

your experience however a person

observing you from outside the event

horizon would see a very different

picture as you were falling into a black

hole they'd see you slowing down getting

dimmer and redder in the end you just

freeze never crossing the event horizon

this is because space and time in a

black hole swapped the roles at the

event horizon time comes to a standstill

while space on the other hand moves

forward you wouldn't be able to turn

around and escape the black hole any

more than you could travel back in time

even when the black hole eventually died

emitting all the particles it had

absorbed including your body it would be

impossible to tell whether those

particles were you Stephen Hawking

however found a way in which the

information about your body wouldn't be

lost he theorized that there are

alternative universes with different

histories this means in one reality you

fell into a black hole in the second one

there was no black hole it's impossible

to be certain from outside of the event

horizon whether there's a black hole or

not until you fall in there if you cross

the event horizon and there was a black

hole sayonara

but if you happen to be in a reality

where the black hole didn't exist you'd

still be alive

just in a different universe there would

be no way for you to get back to ours

would you dare explore the possibility

are you drawn to black holes in the

universe

very soon we'll take you on your next

hypothetical adventure

[Music]