How much do you know about black holes?
What if you fell into it?
Suppose one day you are in space looking for a new planet for humans to live,
but a black hole came out and you decided - why not check it out?
Will you be able to survive in it? How will you get out of it?
Will you go to another universe?
This is Universe Tube
And this will happen if you fell into a black hole-
Despite being "black" and "hole", a black hole is not a dark or empty space.
In the Theory of Relativity, Einstein predicted how black holes are formed.
When a big star dies, it leaves the remaining small core behind.
If the mass of the core is at least three times larger than the mass of our Sun,
then gravity overwhelms all other forces and turns the core into a black hole.
But in the name of black hole, do not think that it is just a hole,
but it is a large quantity of matter which is packed in a small space.
Think about a sun, whose gravity is 28 times more than the Earth.
If you walk on it, your weight will be 28 times more.
Now imagine squeezing four suns in 24 km in diameter. Then what will happen ?
The gravity of a black hole is so strong that even light cannot pass out. That's why you can't see it.
But you can find it with the gamma rays which come from the hole.
Stephan Hawking had discovered these rays, so these are called Hawking Radiations.
Stephen Hawking himself believed that black holes could be the way to another universe.
So if you fell into one, would you find yourself in an alternate dimension?
Every black hole has an event horizon - the point where Gravitational Pull is so much that you cannot escape it.
"The point of no return".
If you are outside that point, you will see the stars turning towards a dark circle.
As you were pull by a black hole, your speed will keep increasing, due to gravity.
The gravitational force of a black hole is very strong.
If your feet fall first, your feet will feel more gravitational pull than your head. Your body will fall apart.
The most common black holes are called "stellar".
They can be up to about 15 km and can be as heavy as 20 suns.
If you were pulled from a stellar black hole, you would die before you reach the event horizon.
Therefore, choose a supermassive black hole, which is millions of times much bigger than our Sun.
Then there will be no harm to your body when you pass through the event horizon.
Because then gravity will pull your feet and head with the same force.
And if you are thinking where to find it - then you do not have to look far away.
One is in the middle of our Milky Way Galaxy.
Luckily, this is 265 quadrillion km away from us. And it will neither pull our Sun nor planets.
But what is the hurry - crossing the event horizon is just the beginning.
There is a gravitational singularity in the middle of the black hole where density becomes infinite.
As soon as you go to the center, you will mix in the black hole and become one.
You will not be able to tell anyone about your experience.
But, if someone is watching you outside the event horizon, then they will see something else.
When you are falling in a black hole, then for them you will go slowly and go dim and red.
And in the end you will stop at the event horizon without ever passing it.
This will happen because space and time change their work in a black hole.
At the event horizon, time stops and the distance and space starts moving forward.
Then you can not turn back and get out of the black hole, but you can go back in time.
Even when the black hole dies, leaving all the particles that were absorbed,
it is impossible to tell which particles are of your body.
But Stephen Hawking had found a way in which your body's information would not be lost.
He said that there are Alternate Universes with different histories.
That means, in one reality you jumped into a black hole but in other reality there wasn't a black hole.
It is impossible to find out from outside the event horizon whether there is a black hole or not unless you jump in it.
But if you are in such a reality, there is no black hole… then you will be saved - in another universe.
But there will be no way for you to come back into your universe.
So, would you like to go to Event Horizon and check whether there is a black hole?
But what if a black hole appear in our solar system?
And what if it swallow our sun?
This is for another video!
