How can anything actually "fall into a black hole" ?

I have to disagree with one point in your question. I don't think time dilation, in this case a gravitational effect, is infinite in the way you think it is. In fact, space time does not exist in a black hole, time stops. This is a finite point. While I have not read Thorne, don't confuse the local event with the remote view of the event.

Think of it like this: Light, unaffected by gravity or velocity is unshifted. As it approaches a mass, a back hole, gravitational induced red shift occurs. As the light approaches the event horizon the red shift approaches infinite. What's happening is as the photons get closer to falling into the black hole the ones that do escape are dramatically slowed, red shifted. At some point a balance will occur, photons are not falling in nor escaping - that's your "infinite" red shift. But of course, motionless photons are invisable to the remote viewer. As this balance shifts to the deep gravitational well, it's gone, fallen into the the black hole.

Things that go near a black hole end up like a bug on a windshield. The word hole in this case is misleading. It is not a hole in the sense of what we know here on Earth like a hole in the ground or a drain in the sink with sides and so forth. A black hole is a sphere like our Earth or the Sun. Like the Sun, a black hole also is a star who's gravity is so strong that light cannot escape it's surface and shine out into space. If you could get close enough to a black hole you would see what would appear to be a dark circle . This is how it came to be called a black hole. Compared to and among all the bright stars in the heavens these strange phenomenon are like a dark hole in space. Knowing this now you can see that anything that gets near a black hole does not go anywhere but to certain destruction

I don't know the answer to this question. I've heard two theories. In one of them, you fall through the event horizon and DIE! either before or when you hit the singularity. This is the usual theory.

In the other theory, as you approach the event horizon, you could look back the way you came and see time in the universe speeding up like crazy. Just as the distant observer never sees you cross the event horizon, you, looking at those distant observers, see all of eternity going by. The galaxies whirl around, stars burn out, trillions and then quadrillions of years go by... out there... while you're falling that last meter to the event horizon.

In that case, then, the black hole will be aging. It might evaporate from beneath you, shrinking even faster than you're falling, and disappearing before you can go in.

On the other hand, maybe black holes don't really evaporate. Maybe quantum processes, such as vacuum fluctuations, are also much slowed by time, so that at the event horizon the time between ANY two events corresponds to an eternity for distant observers. Meaning that distant observers would never see any Hawking radiation in any finite amount of time.

Again, I don't really know what the answer is.

Edit: I think Philip J has the key to the problem. You enter the black hole not by crossing the old event horizon, but by causing the event horizon to expand just a hair farther out as you get close, the event horizon comes up that last little bit and then you're in.

In the proper (local) time of the falling object, it reaches the center of the black hole very quickly. For stellar-mass BH's, it would take only milliseconds.

But if you are watching from a far safe distance, and I am falling into the BH, you'll see me fall more and more slowly as the light delay increases. You'll never see me actually get to the event horizon. My watch, to you, will tick more and more slowly, but will never reach the time that I see as I fall into the black hole. At the same time, I will be getting _dimmer_ and _dimmer_.

As an example, take an 8-solar-mass BH. If you start timing from the moment the you see the object 1.5R away from the event horizon (R), the light will dim exponentially from that point on with a characteristic time of about 0.2 milliseconds, and the time of the last photon is about a hundredth of a second later. At that time, I have disappeared from the outside universe. The times scales proportionally to the mass of the black hole. If I jump into a black hole, I don't remain visible for long. For all practical purposes, I have fallen into the BH in about 0.01 seconds.

The Black hole was originally called a 'Scwartzhilde Discontinuity' for a reason.

We can't reliably project a 'curve' of motion or anything else beyond it.

That the mass is still 'there' in the whole object from our point of view is

confirmed by observation.

What happens at and beyond that event horizon, (the horizon expands with any

added mass doesn't it?), is a matter of conjecture,

which is why Kip Thorne didn't answer your question.

"The closer you look, the weirder it gets."

Matter falling in never reaches the event horizon that existed before it got there. Instead, the increased mass moves the event horizon outward, swallowing up the new mass. So the new mass is inside the new event horizon but outside the old event horizon.

The time dilation effect which you refer to is from the perspective of an observer well outside of the black hole. Remember time is relative, objects or being falling in would not notice.

Its mass is very big that it can bend space and distort it downward, as explained by Einstein's theory of relativity. Black Holes are like a massive Stars graveyard, they formed like normal Stars do. They end their lives different than small mass stars. keep in mind that not all massive stars turn to black holes. As for the process of formation, because the star has so much mass, it doesn't lose its layers but rather compress it to the core, and gravity gets stronger, it is so collapsed that the escape velocity that you need to get away is more than the speed of light, so even light cant escape from it.

We can't assume -- yet -- that the universe will ever pass out of existence. So the fact that falling into a black hole takes infinite time in some reference frames, but finite time in others, doesn't present any problem to me.

Great question! Within our singularity universe there are really only two things; static matter and continuously expanding time and space. When mass enters the BH, time and space are forced to curve away from it a bit more; this "compaction" of expanding time and space (as it curves around mass) is what we experience as the acceleration of gravity. The bigger the mass of a BH, the larger the impact it has on the expanding time and space around it.

I agree that time and space are excluded from the interior of a BH