Last month, i was watching an anime series about time travel (Steins Gate), and then i learned the term 'Kerr black hole'. upon further research, i read that these are theoretical singularities without an event horizon. i don't matter if these are suitable for time travel, but this 'naked singularities' can be real? the relativitity allow these to exist? i want to hear your oppinions about this matter.
>>7764541
>inspired by chinese girl cartoons to look up something
kill yourself
>>7764541
No they don't exist, no relativity does not allow them to exist.
Sounds like a good meme though.
>>7764550
well... it's obvious that you're a person that don't have any serious idea to comment. find psicological help :v
>>7764552
can you explain me about that plz?
They don't exist.
Also, when does Steins Gate mention a Kerr Black Hole, or any black hole?
>>7764552
Actually, you CAN strip the event horizon off a singularity, just like you can strip the reaction field off from a point-particle like an electron, it's just something the universe does to protect itself from the worst effects of both.
>>7764550
Hello reddit.
>>7764985
They were there as a hand-wavy explanation for how the 'phone microwave' was supposed to work. For all I know it was emphasized more in the VN but it's in the show too, at least the subbed version I saw.
I never finished reading steins;gate because I took a break from it while in uni. By the time I got back to it i realized how assbackwards the science fiction was and couldn't get myself to take it seriously anymore. Which is a real shame because I really enjoyed it.
These calculations are doctorate-level, and very specific to Relativity specializations whose interest is black holes, so I don't know the math and neither do any of my university's professors.
But we did attend a talk by one who worked on cosmic censorship. Instead of Kerr black holes, they looked at Reissner-Nordstrom black holes (highly-charged black holes instead of spinning ones) but they argue that their work can also apply to Kerr black holes.
The problem with overcharged Reissner-Nordstrom black holes (which is what we need for a naked singularity) is that theoretically, they can't form all at once; the EM interaction just won't let you cram that much mass into a small enough space. But someone thought, "what if we had a black hole whose charge-mass ratio was right below critical, then we throw in a particle with more charge than mass to sort of tip it over?" It seemed like this was the way to create a naked singularity.
The talk's speaker tried to look at this case and found that the particle's electromagnetic self-force would actually prevent it from falling into the near-critical Reissner-Nordstrom black hole; the EM repulsion turns out to be just strong enough to push the particle out.
So yeah, overcharged Reissner-Nordstrom black holes are still safe from being naked singularities, as far as we know.
The speaker's paper (his name is Ian Vega): http://arxiv.org/abs/1211.3889
The paper's abstract says a similar argument applies for overspinning Kerr black holes, but I don't remember how he explained it. Probably something like a Kerr black hole with an angular-momentum-to-mass ratio just below critical, then throwing in a spinning particle to tip it over to critical.
>>7765388
same anon
Also wait, Kerr black holes DO exist. At least, there's nothing stopping them from existing. What CANNOT exist are overspinning Kerr black holes, which are cases of a naked singularity.
>>7765399
Thanks for your info. how do you know about all this matter?
>>7765722
I'm a physics undergrad (all set to graduate this sem, hopefully). I was there during Dr. Ian Vega's talk; I think he's an alumni of our university or something.
>>7765897
wow great, congratulations! well... we can talk in another time? you're a physic, so we could understand to each other, about subjects related to physical phenomena :)
>>7766075
sure, but how exactly? I'm not about to give away any personal details on 4chan.
>>7766075
kek
>>7765004
Isn't the only theorized way to do that by spinning it really fucking fast though? At a speed that is likely impossible?