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I was reading Quora answers. Someone asked how long it would take to get to the center of a black hole. Their answer (with no explanation or calculations) was 10 minutes for a Supermassive and 6 microseconds for a stellar mass.

So - I would like to see what the actual time is...

For a stellar mass BH of 5 solar masses. If I cross the event horizon at a leisurely 1 meter per second (in my plane of reference) how long till reach the singularity?

For a supermassive BH of 1 million solar masses, how long would it take me at the same speed?

And how are these calculations made?

foolishmuse
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Rick
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  • Why don't you make the question about how one estimates the time interval instead of just memorizing facts? – Connor Behan Dec 21 '21 at 23:19
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    https://physics.stackexchange.com/a/403556/55662 and https://arxiv.org/abs/0705.1029 both have an equation for proper time intervals, but don't necessarily address the "how are the calculations made" question. – BowlOfRed Dec 21 '21 at 23:33
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    The Hawking radiation calculator (which I've linked for you a while ago) can answer questions like that. – PM 2Ring Dec 22 '21 at 00:42
  • BTW, you can't cross the EH of a 5 solar mass BH at 1 m/s. The freefall speed approaches c, so your rocket needs insane acceleration to counteract that as you approach the BH, and no rocket will help as you actually cross the EH. Also, the BH has a Schwarzschild radius of ~14.766 km, and the tidal force at 133 km is sufficient to rip apart a 1 m long bar of A36 steel (falling vertically). See https://physics.stackexchange.com/a/631427/123208 – PM 2Ring Dec 22 '21 at 00:56

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