What happens in a black hole?

The "black" sphere you are probably referring to is the event horizon. This is the distance from an object at which light can no longer escape it's gravitational pull. It is a sphere.

On the inside is what's known as a singularity. This is where the mass of the black hole is stored. Matter enters through the event horizon and gets pulled into the singularity, where it remains until it gets 'ejected' from the black hole due to Hawkings' Radiation.

A black hole is a mass so large and so compressed that its own gravity is too strong to let anything escape. This includes light, which is why it's black. All the mass is compressed down into a singularity with no size, so we're running out of language to describe any more about it. Around the black hole is an event horizon, which is as far as you can go without being sucked in with no hope of getting out. This is spherical for the same reason as stars and planets are round.

It has nothing to do with antimatter. It's just very high gravity that makes it what amounts to a hole in space. A black hole may or may not move fast across the universe.

It used to be thought that a black hole can't "die" - there's no reason why it should. It's just THERE. Stephen Hawking's work, however, shows that because of quantum tunnelling, they do eventually "evaporate" and what gets out is known as Hawking radiation. The smaller the mass of the black hole, the faster it will evaporate and eventually disappear.

Actually, to be technical the black hole isn't the lightless sphere around it. The black hole itself is actually a singularity that has no dimensions (in theory)

The blackness is called the event horizon. It isn't a 'thing' in the sense it is made of anything. It's a result.

The event horizon is simply there because it is at that specific distance to the black hole that light itself is vulnerable to the immense gravity of the black hole.

As far as what goes on within the confines of event horizon, obviously we'll never know. We can speculate that whatever gets to that point will be ripped apart on a subatomic level instantly, safe to conclude since if even light, the fastest moving thing in the universe, are interfered by the gravity, just imagine matter going into it.

Its spacetime properties have many different ideas among astrophysics communities that is a debate that'll never be resolved for certain. Some think time ceases at a certain point deeper in the event horizon. Some say there isn't space between the 'edge' of the event horizon and the singularity, because of gravitational distortion.

We do know one thing for sure though, time dilation is a reality, and gravity is a factor to it. Therefore it's safe to conclude that a black hole, a near infinite density, has some effect of time within the event horizon, if not even beyond that point for a distance. It is a significant difference, however we can't say for sure what the difference would be.

Everything comes out as hawking radiation eventually, after a very long time.

Nothing happens inside a Black Hole - exactly nothing because time has (from our point of view) stopped in there.

Given a big enough gravity field matter compresses, given a very big field matter collapses into Neutrons - all of the Protons and Electrons got packed down into Neutrons (no that is not the exact truth but it is very close). That releases a lot of energy. But that collapse makes the gravity field greater so the Neutrons press together so much that they collapse into Quark Soup, also known as Strange Matter. A blob of free quarks.

Quantum rules hold that up for a moment and then the increased gravity field starts the quarks collapsing together towards forming a singularity. The maths is iffy but during the collapses from Iron to free Quarks the gravity field becomes so intense that time dilation becomes very real and large.

Acceleration and being in a gravity field cause time dilation. Acceleration to light speed causes time dilation "tending to infinity" well that can also happen if there is an intense enough gravity field.

So time dilation happens around the blob of Quarks - when the blob is small time dilation tends to infinity and the blob freezes in time. No singularity ever forms.

A volume of space around the blob is also frozen in time - the line in space where this dilation takes ove is the Event Horizon. Anything falling in now freezes in time just above the event horizon - this includes light which is why it is Black.

As mass increases at the Event Horizon then the Event Horizon creeps outwards engulfing the mass that fell in.

So - inside the Event Horizon is a small but massive blob of Quarks surrounded by space with a haze of quarks and leptons - all of it frozen in time.

We can't ever find out.

A black hole swallows everything, including light and information. It never comes out again. Thus it is not possible to see what happens inside.

If anything comes out of a dense object, with or without accretion disk, then there is no such thing as a black hole.

Cheers!

Sphere (at least the "Event horizon" part).

anti matter? : we don't know

also does a black hole move fast across the universe?: mostly not