The mass of a super-massive black hole measured in suns

how does that happen

Objects usually take up space because their charged particles - electrons and protons - are pushing each other apart. Electrons pushing electrons is why you can touch things and why your hand won't just fall through a table, even though atoms are mostly empty space. Protons pushing protons is why nuclei have dimensions and aren't point masses.

Now, a black hole happens when matter is packed densely enough that all these repelling forces are overcome and all the particles attract each other despite these forces. This makes the matter more dense, which in turn strengthens the gravitational force further. Because there's nothing pushing these particles apart, we end up with them all occupying the same point in space - they become a singularity.

A black hole's Schwartzschild radius isn't really its dimensional size. If I remember correctly, it's the distance from which the black hole's gravitational pull is so strong that literally nothing can escape it. I suggest you do some googling about that part, because I find it quite cool.

EDIT: one thing I'd like to add - the reason why we say the singularity "takes up 0 space" instead of "takes up only a little space" is because in chemistry and physics, we define the dimensions of particles, atoms and molecules by how far they are from the particles next to them. Since in a black hole the particles are all literally in the same spot, not just very near to each other, there is no distance or dimensions to measure or define, and thus we say that the volume of the singularity is 0.

Whether this is true is, if I'm not mistaken, basically impossible to determine, because the way we measure things in science is we bounce light, electrons or other particles off the thing we want to measure and then see how they change. A black hole just absorbs all these particles and we're none the wiser.

/u/justwondrin did a pretty good job of explaining what 'taking up space' actually entails, but I think your confusion mostly - or at least partially - lies elsewhere.

The term "black hole", when discussed in science, does not refer to the black circle in this. This is a fucking HUGE misconception that the general public has about black holes! It's sincerely upsetting.

The mass of a black hole doesn't take up any space (theoretically ^{sort of} ). Meaning its volume = 0. Meaning it's a singularity! And that theoretical object exists at the very center of the black circle in that picture I linked. The black circle's edge is called the event horizon. It's defined by the ability of light to escape the gravity of the black hole. It is not the actual object itself.

Hope that's helpful.

For the foreseeable future our solar system will continue to orbit that black hole. I'm not entirely sure what your second question is asking.

Just as Earth is falling into the sun, the whole galaxy is spiraling(collapsing) into that black hole, so it's just a matter of time, we are already under it's gravitational pull.

Unless the collision with Andromeda knocks it away first of course.

:|

I sea what you did there.

Awe, it is ok little fella. There are creams and pumps for that kind of thing.

Actually, when you get to billion arithmetic calculations, modern machines do get problems keeping up. CS student here.

No, there aren't. There are billions of stars, but only one of them is the Sun.

If it was shrunk down that much it would collapse into a singularity.