🧵 Somewhat recent developments in Kerr/RN black hole space times
Anonymous at Sat, 8 Feb 2025 07:52:19 UTC No. 16579252
I'm tryna get a gist on what the current state of affairs on that kerr black hole according to the boffins' top blackboard scribblings.
So we have the normal schwarzschild spacetime. Here it's just a space like singularity ahead of the event horizon and apparent horizon. Just before hitting this curvature singularity (or reaching it in time) one entire 180 degree horizon is pitch dark and bisected by severely lensesd starlight. Fine then.
There was a ring singularity, inner horizon in the kerr metric. But it was known not to be stable outside the event horizon. Same with charged BH and such horizon.
Here's a good vid of the maximally extended space time, but again, not stable:
https://www.youtube.com/watch?v=fPy
In the 1960s Penrose suggested an issue, in 90s confirmed of "mass inflation" that will result in a mix master BKL space like singularity (doing away with ring singularity) and fuck up the inside. Even one popcorn can strike another popcorn at Lorentz factors of > 10^35. More than big bang energies.
Anonymous at Sat, 8 Feb 2025 07:53:11 UTC No. 16579253
contd.....
Then Thorne and his team of top bro scientists did the IntheStella movie ain't it. He released a pop sci book with the film. Now he says this mass inflation, is a "weak" null singularity we might be able to walk off. Plus some GR guys in 2012 found another god dam singularity - the "upflying" or "shock" singularity". The space like BKL bad boy remains.
The BKL is actually studied (or studied near it) on the manifold rather than just piece removed, so has some odd but predicated features like getting squished then squashed in "eras" all back and forth rather than one spaghetti. What a weirdo.
Pic related of this is in the above message^^^
The issue is, this guy Hamilton, expert at Colorado says mass inflation singularity is strong, will kill you to shit, and says no shock singularity (?).
Thorne says, akshaully no. And others saying other shit too, like the ring actually being a thing after all that , maybe.
So what's the deal for these weirdos. Is it pic rel so the other guy has dropped the ball? Thanks you GRists. I'm too scared to post on stackexchange.
Anonymous at Sat, 8 Feb 2025 09:43:27 UTC No. 16579291
Still early, and hardly enticing thread..... but no reply so far ....... is there no one here who can put GR on the bleeding edge. No one with the expertise. Even that smug bastard on tv gets softballed all the time. Are we fellow dilettantes or are u gonna give me a helluva dressing down.
I know the subject is almost useless (nope, GPS doesn't need relativity to work properly). But surely there's a guru lurking round here who knows this goobley gook. Or some guy receiving gov money to draw up spacetimes all day long. That's what general relativists do these days now that the computer can do all the Christoffel symbols rite? Or film themselves on youtube.