So all that needs to happen is for your head to enter the future light cone of your feet before your head hits the singularity. The speed of your feet is somewhere between those two, as is the speed of your head. You'll probably believe that they have different speeds. Basically, think of two light rays given off by your feet: one directed toward the singularity, and the other directed away from it. Which means that relative to your head light can still move outward, as can a nerve impulse. But your head (and your feet) are moving toward the singularity faster, so your head enters into the light cone of your feet. This means that even light pointed outward can't actually move outward the outward-pointing light ray will still be moving toward the singularity. And inside the horizon, those light cones "tip over" towards the singularity. You'll typically see this sort of thing represented by a graph of the light cones. And that's entirely allowed everywhere, even well inside the black hole. Instead, it just needs to move inward more slowly than your head. So your head is moving at roughly the same speed as your feet, which means that the signal doesn't have to actually move outward relative to these stationary coordinates (it can't).
Your head and feet are being "accelerated" at basically the same rate (relative to some stationary coordinate system, let's say) because you are so small compared to the black hole. On the other hand, if you are falling into the supermassive black hole (even if you jumped off this crazy rocket just an instant earlier), things are very different. :) But those aren't tidal effects they're acceleration effects. I don't think anyone would claim you wouldn't feel anything if your head were attached to a rocket keeping you out, while your feet dangled inside the black hole. If your head were somehow stuck just outside the horizon, † you would be right. At some point, it will be so small that it's "in the noise" and you don't even notice it. The bigger the hole or the farther you are from it, the smaller the difference will be. You would feel this as a slight tug on your feet. Your feet are slightly closer to the center of the black hole, so they will experience a slightly greater acceleration than your head. In this case, I mean the difference between the acceleration of your feet and your head. Tidal effects are the difference in gravitational "force" on two different parts of an object. So let's assume the black hole is supermassive - or more specifically that you are really tiny compared to the black hole - so that we can ignore tidal effects. This is a great question, because it's a subtle variation on the usual question about spaghettification and supermassive black holes, and shows somewhat deeper thinking.
0 kommentar(er)
