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> From what I've read, it's thought that inside the event horizon, black holes are almost totally empty until you get to the singularity (or torus if it's spinn

> From what I've read, it's thought that inside the event horizon, black holes are almost totally empty until you get to the singularity (or torus if it's spinning) at the center. I can see how this could maybe be true for a black hole that never has anything fall into it after yourself, but for regular black holes that have things falling in regularly I think the situation would be pretty different. As you get closer to the event horizon, the rest of the universe appears to speed up. This means that as you get closer, the rate of objects / energy coming into the black hole past you and sometimes colliding into you will increase. You can imagine that at some point near the event horizon, every second, 100 years will pass for the rest of the universe, and 100 years worth of debris and light will enter into the black hole, some of it colliding with you. As soon as you reach the event horizon, an infinite amount of time's worth of debris and light will enter into the black hole, some of it colliding with you. From inside the black hole, it must look like everything that has ever fallen into the black hole in the history of the universe has fallen into it at the same instant. (And then I'm not entirely sure how black hole evaporation fits into this. I'd expect the perspective of someone going into a black hole must look like you immediately collide with everything that ever has and ever will fall into the black hole, and then instantly everything is obliterated into Hawking radiation.)

wwarner 7y ago
I'm just a reader, but Kip Thorne doesn't agree with your picture. In his book, he claims you wouldn't notice passing through the event horizon, except for extreme tidal forces that would tear you apart. The time freezing and red shifting reverse so that looking away from the center, distant objects move faster and are bluer. His book for the layman is Black Holes and Time Warps.
- shagie 7y ago
  The tidal forces depend on the size of the black hole. http://www.hawking.org.uk/into-a-black-hole.html http://www.hawking.org.uk/into-a-black-hole.html > ... If you fall towards a black hole feet first, gravity will pull harder on your feet than your head, because they are nearer the black hole. The result is, you will be stretched out longwise, and squashed in sideways.. If the black hole has a mass of a few times our sun, you would be torn apart, and made into spaghetti, before you reached the horizon. However, if you fell into a much larger black hole, with a mass of a million times the sun, you would reach the horizon without difficulty. So, if you want to explore the inside of a black hole, choose a big one. There is a black hole of about a million solar masses, at the center of our Milky way galaxy.
pdonis 7y ago
> As you get closer to the event horizon, the rest of the universe appears to speed up. Only if you are using rocket power to "hover" at a constant altitude above the horizon (and the amount of rocket power you need increases without bound as you try to hover closer and closer to the horizon). If you are free-falling in, the rest of the universe actually appears redshifted, not blueshifted.
pdonis 7y ago
> from inside the black hole, it must look like everything that has ever fallen into the black hole in the history of the universe has fallen into it at the same instant. No, that's not correct. You can see things that have fallen in before you, but not after you. There are still distinct points on the horizon where things can cross, and distinct trajectories inside the hole. > I'm not entirely sure how black hole evaporation fits into this Nobody knows for sure because we don't have a good theory of quantum gravity. In Hawking's original semi-classical model of black hole evaporation, things that fall into the hole before it evaporates are still destroyed at the singularity, but if you wait outside and watch the hole evaporate, the final burst of light as the hole finishes evaporating and disappears will contain images of everything that fell into the hole, at the instant it crossed the horizon. However, it's not at all clear that that model will still be a good approximation when we have a full quantum gravity theory.

wwarner 7y ago

I'm just a reader, but Kip Thorne doesn't agree with your picture. In his book, he claims you wouldn't notice passing through the event horizon, except for extreme tidal forces that would tear you apart. The time freezing and red shifting reverse so that looking away from the center, distant objects move faster and are bluer. His book for the layman is Black Holes and Time Warps.

shagie 7y ago
The tidal forces depend on the size of the black hole. http://www.hawking.org.uk/into-a-black-hole.html http://www.hawking.org.uk/into-a-black-hole.html > ... If you fall towards a black hole feet first, gravity will pull harder on your feet than your head, because they are nearer the black hole. The result is, you will be stretched out longwise, and squashed in sideways.. If the black hole has a mass of a few times our sun, you would be torn apart, and made into spaghetti, before you reached the horizon. However, if you fell into a much larger black hole, with a mass of a million times the sun, you would reach the horizon without difficulty. So, if you want to explore the inside of a black hole, choose a big one. There is a black hole of about a million solar masses, at the center of our Milky way galaxy.

pdonis 7y ago

> As you get closer to the event horizon, the rest of the universe appears to speed up. Only if you are using rocket power to "hover" at a constant altitude above the horizon (and the amount of rocket power you need increases without bound as you try to hover closer and closer to the horizon). If you are free-falling in, the rest of the universe actually appears redshifted, not blueshifted.

pdonis 7y ago

> from inside the black hole, it must look like everything that has ever fallen into the black hole in the history of the universe has fallen into it at the same instant. No, that's not correct. You can see things that have fallen in before you, but not after you. There are still distinct points on the horizon where things can cross, and distinct trajectories inside the hole. > I'm not entirely sure how black hole evaporation fits into this Nobody knows for sure because we don't have a good theory of quantum gravity. In Hawking's original semi-classical model of black hole evaporation, things that fall into the hole before it evaporates are still destroyed at the singularity, but if you wait outside and watch the hole evaporate, the final burst of light as the hole finishes evaporating and disappears will contain images of everything that fell into the hole, at the instant it crossed the horizon. However, it's not at all clear that that model will still be a good approximation when we have a full quantum gravity theory.