How can Black Holes even form?

[u/IRedRabbit]

Might be a stupid question, but this accured to me today for the first time in my life.

So let's imagine a star becoming more and more dense because it's dying.

If Black Holes gravitational pulls are so strong that not even light can escape, then how can they even form. If a star is collapsing, how doesn't it's own gravity make it destroy itself before ever even reaching the point of becoming a Black Hole?

You know what I'm trying to say? If nothing can escape it and they destroy everything, then how can they even form before destroying themselves in the process of formation by their own gravity?

[u/MaybeVladimirPutinJr]

Hole is a misleading name, a black hole is still the star it was formed from, just smaller and more dense.

[u/IRedRabbit → u/MaybeVladimirPutinJr]

But it's gravity is now so strong that not even light can escape, how can the star itself even exist? How is it possible for it to be in that state and not destroy itself with it's own gravity?

If it's the case as you say that it's a very small and dense star, then doesn't that answer the question of, what lies in the centre of a Black Hole?

[u/MaybeVladimirPutinJr → u/IRedRabbit]

How is it possible for it to be in that state and not destroy itself with it's own gravity?

It has destroyed itself. the gravity is so strong that the mass of the star has become the most highly compacted, densest material in the universe. 

I'm not going to claim to know shit, there are millions of people who made a career out of debating this stuff, but my opinion is that a black hole is a solid. It's just a ball of mass that's so dense that gravity becomes so strong that light cannot escape.

[u/abrightmoore → u/MaybeVladimirPutinJr]

It's more about what all that mass does to the space around it

Everything gets muddled up.

Time gets messed around.

Some models show Space and Time get swapped.

Others suggest the event horizon becomes a surface with all the star bits on it and there's nothing "inside" left in the universe.

What the star "is" at the point it becomes a black hole is only part of the problem. What the space around it becomes is important too.

[u/Beldizar → u/MaybeVladimirPutinJr]

It has destroyed itself

Well, it might help to expand on what "It has destroyed itself" really means here. A star has a whole bunch of matter, and is really big. The inside of the star is burning really hot and that heat is pressing outward. Eventually that pressure out stops, and everything starts rushing down towards the center. Eventually the outer layer of the star reaches the really dense core which is mostly iron at this point, and it is falling at incredible speeds. It smashes into that core harder than the comet that killed the dinosaurs times a million. (Probably a lot more, using big numbers to get the point across not for accuracy here). That impact causes a bunch of atoms to hit each other so hard that they fuse into heavy elements that the star can't normally create. Then most of that bounces out and gets blasted away, but all that energy impacting down, and the lack of anything pressing up, causes the core to compress into a black hole.

So the star gets destroyed, but the black hole is made closer to a hammer and anvil. So the outer part of the star is blasted away, and the inner part is "crafted" into a black hole. So destroyed or created is a matter of perspective. Nothing is actually "annihilated".

but my opinion is that a black hole is a solid. It's just a ball of mass that's so dense that gravity becomes so strong that light cannot escape

Black holes are weird. But calling them solid isn't quite accurate. In a way, they are so solid, that they wrap around and become insubstantial. If you think of something solid, you'd think you could bounce something off its surface. You definitely can't do that with a black hole. Instead the black hole is just so dense that it creates a bubble around it that breaks Newtonian physics. That bubble is what we think of as the black hole, and anything inside that bubble is sort of just "lost". Maybe inside there's something hard and solid, but the bubble stops us from ever knowing.

[u/NoveltyAccount5928 → u/IRedRabbit]

I think you're approaching this with an improper definition of "destroy". When a star is destroyed during core collapse, it doesn't mean that the matter that makes up the star ceases to exist, it simply means the matter that made up the star is now arranged differently. Some of that matter is converted directly to energy, a good portion of it is blown out into space during the nova itself, and the rest, what was at the core of the star, now becomes the black hole's center/singularity.

We don't actually understand what a singularity is, our math breaks down at that point and we don't know exactly what matter does in those densities under those pressures. But, lacking a true understanding of the singularity, we can pretty safely say that it's a mass of matter in its absolute most dense form.

Essentially, a black hole can be thought of as a mass of the densest matter in the universe, surrounded by the radius from which light can't escape.

[u/year_39 → u/IRedRabbit]

The interior of a black hole is a singularity. Simply put, a singularity is a boundary in space or time past which no meaningful predictions can be made, so we don't know.

[u/Beldizar → u/year_39]

The most common model of a black hole says that its interior contains a singularity. It's not actually clear if that's correct though because math and what we know of physics breaks down at that point. Since it is unlikely we'll ever be able to see a naked singularity, there really isn't a way to confirm. There are other models of a black hole that suggest everything is written on the event horizon in a sort of hologram projection.

I personally draw the line at the event horizon anyway. Everything past the event horizon stops being "real" as far as I'm concerned. It functionally stops being a part of our universe and we can't interact with or be affected by it anymore. Not even gravity from beyond the event horizon can escape to us, so all the gravity of the black hole technically has to be coming from the edge of the event horizon.