Black Holes, Singularities, Confusion

In the thread A Big Bang Misconception cavediver brought up some interesting stuff (well, I found it interesting).Alas, it's off-topic, but I would still like it to be explained, and am hoping that cavediver or anyone else who knows this stuff (no creationist nonsense please) can explain it.For reference:

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cavediver writes:

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percy writes:

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And a spinning singularity is a possibility, too, I assume?

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Yes. We usually regard the singularity of the Kerr solution (it's a black hole) as the source of the ang mom. But the singularity itself is very weird: it's in the shape of a ring. However, if you pass through the ring, you end up somwhere different than if you just go round the outside! You have to go round twice to get back to where you started from

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kuresu writes:

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the ring-shaped singularity?
any relation to the blackhole type that could hypothetically be used for wormhole travel?

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mind explaining it a little further when you get some time?

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cavediver writes:

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kuresu writes:

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any relation to the blackhole type that could hypothetically be used for wormhole travel?

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OT here. If you or someone wants to start a thread on a black hole q&a then I probably won't be able to resist putting some time in.

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But for now: yes it is related but not because of the ring nature of the singularity, but becasue of the dual "charges" of the black hole: "mass" and ang. mom. - yes, I know I said the Kerr solution has zero mass, but this is a different "mass"

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All a man's knowledge comes from his experiences

Thread moved here from the Proposed New Topics forum.

Thanks Kuresu! Bit busy at the moment, but will be back later...

bump for cavediver on blackholes

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All a man's knowledge comes from his experiences

Well, I need a bit more than that... it's a big subject Was it the wormhole aspect of Black Holes you wanted to explore, or singularities, or something else?Just to start: the usual wormhole mentioned wrt black holes is the Einstein-Rosen Bridge, which is not really a wormhole at all. It is simply the observation that a mathematically pure black hole (not the type that results from collapse of a star for example) is actually a connector that joins two infinite spaces or "universes". Unfortunately, as much as it is a connector, it is also a restrictor, in that it restricts any communication and/or travel between the two universes, unless you can travel FTL, which sort of defeats the point! We call it a wormhole because if you take a cross-sectional (spatial) slice of the black hole, it looks like a wormhole despite its total impracticality.The fun begins when you take a black hole that is rotating and/or charged. The Einstein-Rosen Bridge is still there, connecting the two mutually-inaccessible universes, but there are also an infinite number of Bridges, sequentially stacked along a corridor of time, each with a pair of "universes" that can be accessed once inside the black-hole. It's sort of like the corridor of doors from Matrix-Reloaded and other fantasy works.

I never really considered myself a creationist except at the Cosmological level. It was always pointed out to me that IF a Creator existed, it was always merely a matter of Faith and could NEVER be established through any logical means.I was fine with that. But when I read about multiple universes and the funhouse mirror world of physics, I can only conclude that for some of the more disciplined minds such as yours, God would be no problem to believe in were there only a solid hypothesis that could be followed by a rational mind! I am a layman at this sort of stuff. Walk me through it along with kuresu and perhaps I'll learn something.Black Holes---OK..I knew that they had incredible gravity...so much so that even light could not escape their pull. In my theological world of faith hypothesis, I had already concluded that spiritual light was different from natural light--but I could never come up with a solid theory for spiritual light except to conclude that it did not have to obey any laws.Singularities---The only thing that I knew about singularities was that they were the end result of a collapsed black hole....am I right? And was not the original idea such that the universe was itself a singularity at one point? (no pun intended)Also....was the description of such a point hypothetically that everything was in the same place at the same time???Time is a weird concept when it transcends life (as in a birth death cycle) and stop watches.By the way, cavediver, I was discussing some of the stuff concerning an observer in Guido's thread and wondered what you thought of my idea that God incarnate may have been the original observer??Sorry to mix religious ideas and beliefs up in a Cosmological forum but they are often mixed up in my mind as well.I mean... its hard enough to conceive of one universe....much less multiple ones.Theoretically, if I lived forever and had the ability to study every single aspect of reality, would my need to live forever be a prerequisite for studying an infinite amount of mass, behavior of said mass, and possibilities within such a large area?

Here's some Penrose diagrams (Carter-Penrose for the pedants) of what I have been talking about -Schwarzschild Black Hole (uncharged, non-rotating) is top left. Space is left-right and time is up-down. If you don't move, you trace a line vertically up the diagram as time passes. Speed tips your line over to a maximum of 45 degrees, which is the speed of light. You can see how if your line crosses the event horizon, you are doomed to hit the singularity, as you cannot tip your line more than 45 degrees. You can see some possible astronaut "world-lines" on the right hand diagram.You can see how "our universe" and "other universe" are just regions within one "total universe", connected by the "black hole".The rotating and/or charged balck hole is shown on the right. You can see the "corrdior" stretching off into the future, but it also stretches into the infinite past, with an inifnite number of pairs of "universes" attached.Note that each "universe" is an infinite universe in its own right, both spatially and temporally. So this is an infinity of infinite universes Edited by cavediver, : No reason given.Edited by Admin, : Narrow the diagram.

Hi Phat, Yes, if you check out the diagrams above, you'll see the singularities as jagged lines. Yes, the Big Bang starts in a singularity. Sort of. There is a great problem with this common view of "everything", as if all the atoms and stars and rocks and things were all squished together at the BB. The universe isn't like that. There aren't "things" that live or exist in the universe, just aspects of the universe. The aspects that we call "things": stars, cars, footballs weren't in evidence at the BB, nor for long long afterwards. Think of the universe as the ocean, and "things" as various formations of waves on the ocean. At the BB the ocean was very flat... Perhaps, or maybe we are God observing the universe Not necessrily. Infinite aspects can leave finite signatures.

hi there, is there conclusive evidence that black holes excist , cavediver could
you say yes 100% they do excist and are part of the universe ?also i would like to know what happens to a large object that falls into a blackhole,
does it get crushed to an infinitly small size or stay the same size ??also i keep reading about singularity's and the end of black holes , what sort of state
are these singularity's in ??

may as well start with the basic physics (in layman terms if you can) of blackholes--I think I understand that chart you post with the 45 degree angles, but . . .yeah, a primer in this stuff is probably the best place to start.oh, I did want to explore the wormhole aspect thing--but it looks like the basics are needed first--so we'll get there, and possibly other places too.

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Yes and no. There are definitely objects that meet the criteria for being black holes, but as for whether they are black holes inside the event horizon- in the sense of General Relativity - that remains open. But given how phenomenally successful GR has been so far, it would be hard to understand how they could not. If it falls towards the singularity, yes. In the Schwarzschild this is unavoidable. But in the charged and/or rotating case, the singularities can be avoided. I wish I knew The issue is with a microscopic black hole that is evaporating rapidly via Hawking Radiation. Theer comes a point where it is evaporated its entire mass away. The horizon shrinks to zero size, so what happens to the singularity? Does it remain as a "naked singularity"? Or does it wink out of existence with a bang? It has long been thought that some gamma ray bursters could be endpoints of Hawking Radiation - black holes going pop...

In other words, the ocean had no depth? Well...Do they see the Ocean as having any breadth? or length? (At that BB moment??)There are no limits as to what the human mind can conceive, right? (As long as the conceptions stay within the disciplines of mathematics and physics?)

If the Theory of Hawking radiation is correct, then that would be the exception to the rule of matter neither being created or destroyed. I once heard that Black holes are where God divides by zero.

Matter is created and destroyed all of the time. Two photons (not matter) can stimulate the creation of an electron (matter) and a positron (anti-matter). Conversely, an electron and a positron can annihilate giving off two photons.There is certainly conservation of "mass-energy", but not matter.

so if blackholes and other matter curve space-time then space-time has a "fabric" to it...is this "fabric" energy ?, is the universe just one massive energy field ?cheers