It seems that rclay's questions, in the OP, have not really been answered all that well.
rclay wrote:I have a question (actually, several) about Black Holes:
If these things are at the center of some galaxies, does this explain the whirlpool shape that we see in images? I think of the way water drains out of a bathtub -- is that what's going on, on a galactic scale, except it's light and matter and everything, not just water, being pulled into the hole?
In short, no it does not explain the spiral ('whirlpool') shapes of (spiral) galaxies.
Start with observations: elliptical galaxies, such as
the two prominent in this image of the centre of the Virgo cluster, do not have such shapes, yet do apparently
have supermassive black holes in their nuclei. Further, there may well be spiral galaxies without supermassive black holes in their nuclei.
Next, theory. A disk is the shape which a system of particles, interacting gravitationally, will form ... provided there is some initial angular momentum, and provided there is some way for the particles to lose energy (other than gravitationally). While stars rarely interact with each other (except by gravity), the giant clouds of gas and dust which give birth to stars do. While galaxies, especially those with lots of gas and dust, are very complex systems, the origin of the spiral shape of some galaxies is understood to be a density wave, which travels through the disk and causes local regions of star formation in its wake. Further, supermassive black holes do not act like the drains in bathtubs - in fact, very little matter is being sucked into them (though in their very early days things may have been quite different).
If this is happening, I imagine it's an amazing process at the hole -- but in pictures the galaxies always seem so serene. In my bathtub, as the last bit of water runs out the vortex is more swishy and steep-sided; more violent. Is this true of a black hole?
The details of how a black hole 'swallows' matter are poorly understood, not least because we cannot (yet) study the process except very remotely.
Here is the general idea;
here is a more detailed explanation of one possible mechanism (it's the accretion disk which matters, not the source of the matter nor the size of the black hole).
Are there examples of galaxies that are mostly, like 80%, gone into the black hole? Where does the stuff go when it runs out the drain?
There are no such examples that I am aware of; the supermassive black holes in the galaxies examined to date comprise but a tiny fraction of the galaxies' total masses.
As far as we know, once matter has gone beyond the event horizon, it stays there, except for its eventual re-appearance as
Hawking radiation. However, this emission process is incredibly slow, for massive black holes.
Finally, if time, matter, energy, and lost sunglasses all ultimately go into a black hole in the center of a "doomed" galaxy, doesn't this mean that the amount of "stuff" in the universe is decreasing? Or do black holes just recycle stuff back into the universe? If so, it would seem that we have black holes to suck stuff in, but where are the "white holes" that spew the same amount of stuff back out? (I base this on the idea that nothing is ever really lost or added to the universe, that it's a closed system with a lot of activity within the fixed amount of stuff inside.)
Black holes are just as much part of our universe as the Earth is; they have mass, they can have an electric charge,
they can have spin. All these are very real physical properties!
While there are several theories which combine General Relativity and quantum theory - such theories are necessary to answer your questions scientifically - none has yet been tested much. It may be that there are parallel universes, merely millimetres away, in different dimensions; it may be that there are wormholes at the heart of black holes; it may be that the reality is even queerer than anyone today can even imagine.
We live in exciting times!
Ok, didn't mean to get all Hawking on you, but these are my questions and I'd love to know your responses. Also, the idea of a "white hole" and a return system that counterbalances the process of a black hole is sort of a theory of mine that I'd appreciate not being grabbed and claimed as one's own...nobody can copyright reality, but the ideas we use to discuss reality need to be recognized as the work of the people who take the time to express them, don't-ya-think?
Why not develop these ideas of yours, and make them into a proper, scientific, theory?
If you're interested, Lee Smolin gives some excellent advice on how to do just that! It's in his book, called "The Trouble with Physics", I think.