Black hole☄️what is Black hole,,what's the secret of it..Let's find out.🌌🪐

 

A black hole is a region of spacetime where gravity is so strong that nothing, including light and other electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.

The singularity at the center of a black hole is the ultimate no man's land: a place where matter is compressed down to an infinitely tiny point, and all conceptions of time and space completely break down. And it doesn't really exist. Something has to replace the singularity, but we're not exactly sure what.

What’s inside a black hole?

The short answer is that no one knows!

“In some ways that’s one of the most profound questions in physics,” said University of Chicago Prof. Daniel Holz. “There are not many cases in physics where we simply cannot predict what happens, but this is one of them.”

Black holes have two parts. There is the event horizon, which you can think of as the surface, though it’s simply the point where the gravity gets too strong for anything to escape. And then, at the center, is the singularity. That’s the word we use to describe a point that is infinitely small and infinitely dense.

We have a good understanding of what the event horizon looks like, thanks to the laws of general relativity. But as you get close to the singularity itself, we lose the ability to even predict what it looks like.

“Very near the singularity, one would expect quantum effects to become important. However, we don't yet have a quantum theory of gravity (or, at least, one capable of reliably making such predictions), so we just don't know the correct description of the singularity—or even whether it really is a singularity,” said University of Chicago Prof. Robert Wald.

Scientists think that black holes eventually will explode, but it will take many, many times longer than the current age of the universe for that to happen. What will it look like when that happens? That’s another big mystery.

“Maybe there’s a little nugget left behind containing all of the information that fell into the black hole, maybe there’s a portal to a new universe, maybe the information is just gone forever; we simply don’t know,” said Holz.

(If all of this is unsatisfying, know that it keeps scientists awake at night, too.)

How do black holes form?

Scientists know about one way that black holes form, but there may be others.

One way to make a black hole is to have a massive star collapse at the end of its life. Prof. Subrahmanyan Chandrasekhar was the first to calculate that when a massive star burns up all its fuel, it will collapse. The idea was ridiculed at first, but other scientists calculated that the star continues forever to fall inward toward its center—thus creating what we called a black hole.

Black holes can grow more massive over time as they “eat” gas, stars, planets and even other black holes!

There’s another type of black hole called a supermassive black hole. These are way too massive to have been created by one star collapsing; it’s still a mystery how they form. Black holes can eat other black holes, so it’s possible that the supermassive ones are made of many small black holes merged together. “Or perhaps these big black holes were especially hungry, and ate so much of their surroundings that they grew to enormous size,” said Prof. Holz. But we can see these supermassive black holes formed very early on in the universe—maybe too early to have been made by stars getting old enough to collapse—so it’s possible there’s some other way to make a black hole that we don’t know about yet.

What is a supermassive black hole?

There are two kinds of black holes: star-sized black holes and supermassive black holes.

Supermassive black holes are so named because they contain on the order of millions to billions times the mass of our sun.

As far as we can tell, nearly every galaxy in the universe has one of these supermassive black holes sitting right at its center like a seed. And they are correlated—a bigger galaxy has a bigger black hole, and a smaller galaxy has a smaller black hole. All of this makes scientists think these supermassive black holes have something to do with how the galaxies formed. But that relationship is still a mystery, and so is how the supermassive black holes formed in the first place.

Our “neighborhood” supermassive black hole, the one at the center of our own Milky Way galaxy, is called Sagittarius A* (pronounced A-star). It’s about 15 million miles across and contains the equivalent of 4 million suns’ worth of mass. Don’t worry; it’s much too far away to pose any danger to Earth.

What do black holes eat?

Contrary to what you may have seen in movies, black holes don’t actually “suck” things in. For example, there are actually stars orbiting the supermassive black hole at the center of our galaxy, and they’ll keep orbiting without falling in unless something else disturbs them. An object really has to fall right into.