So I'm still thinking about black holes, but hey, you can't blame a guy for thinking about holes, right?
Which actually brings me to a previous thing I STILL don't understand. Which probably won't surprise anyone, since I'm still not a trained physicist. So I'm probably missing something, and I KNOW that, so please explain slowly and in simple words, like for Pixie Of Key :p
So: premise 1: gravity propagates at the speed of light. This was empyricaly proven recently when the gravity waves from a merger reached us at the same time as the light.
Premise 2: inside the event horizon all light cones lead to the centre. Even light can't go towards the outside at all.
It seems to me like if the matter were concentrated in the centre (either singularity, Planck density, or really anything smaller than the event horizon) then the information that there's some mass there distorting space couldn't actually reach any matter that just crossed the event horizon. That would involve something moving at the speed of light going outwards. Which it can't.
And yes, I know, the event horizon is only a coordinate singularity, only in Schwarzschild coordinates, etc. You explained that to me already. I think I get it. But no matter what coordinates I use, information still can't go outwards without going superluminal. (Unless I'm missing something. Which I probably am.)
It seems to me like the only way something behaving almost like one from outside could possibly form, is to never actually form a black hole. Like, stop at the Schwarzschild radius + 1 Planck length, or something like that. That's the only way that information that there's a big mass there can possibly flow outwards without going superluminal.
As usual, I'm not actually Pixie Of Key or such, so I realize that if my understanding differs from that of actual physicists, it means I must be the one who's wrong. I'm not gonna go crackpot here and play Secret Socrates or anything. But that leaves me wondering WTH do I get wrong there. Anyone who can explain in simple words, I'd be most grateful.
Which actually brings me to a previous thing I STILL don't understand. Which probably won't surprise anyone, since I'm still not a trained physicist. So I'm probably missing something, and I KNOW that, so please explain slowly and in simple words, like for Pixie Of Key :p
So: premise 1: gravity propagates at the speed of light. This was empyricaly proven recently when the gravity waves from a merger reached us at the same time as the light.
Premise 2: inside the event horizon all light cones lead to the centre. Even light can't go towards the outside at all.
It seems to me like if the matter were concentrated in the centre (either singularity, Planck density, or really anything smaller than the event horizon) then the information that there's some mass there distorting space couldn't actually reach any matter that just crossed the event horizon. That would involve something moving at the speed of light going outwards. Which it can't.
And yes, I know, the event horizon is only a coordinate singularity, only in Schwarzschild coordinates, etc. You explained that to me already. I think I get it. But no matter what coordinates I use, information still can't go outwards without going superluminal. (Unless I'm missing something. Which I probably am.)
It seems to me like the only way something behaving almost like one from outside could possibly form, is to never actually form a black hole. Like, stop at the Schwarzschild radius + 1 Planck length, or something like that. That's the only way that information that there's a big mass there can possibly flow outwards without going superluminal.
As usual, I'm not actually Pixie Of Key or such, so I realize that if my understanding differs from that of actual physicists, it means I must be the one who's wrong. I'm not gonna go crackpot here and play Secret Socrates or anything. But that leaves me wondering WTH do I get wrong there. Anyone who can explain in simple words, I'd be most grateful.
via International Skeptics Forum https://ift.tt/CSa6Gvt
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