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Black Hole Evolution Traced Out with Loop Quantum Gravity

physics.aps.org

11–20 of 32 posts

Re: Black Hole Evolution Traced Out with Loop Quantum Gravity

#11
post #10

Are Gray Holes next? When a White Hole and a Black Hole merge a Gray Hole will emerge as predicted by the Chromatic Theory of General Relativity.

I was wrong! Grey Holes have been invented already! http://adsabs.harvard.edu/full/1993AAS...182.5507B

Re: Black Hole Evolution Traced Out with Loop Quantum Gravity

#12
post #9
post #5

Earlier quoted context omitted.

My understanding is the transition to a white hole exists instead of a singularity at the interior of the black hole, and is therefore hidden by the event horizon. When the event horizon shrinks to the Planck length, the white hole is exposed.

Yes, but the event horizon shrinks by emitting Hawking radiation, right? When the white hole is exposed, what it looks like? Is it just hole in the space that does not emit anything? Nothing exits (because Hawking radiation already emitted all of the energy) and nothing can enter. What is the radius of the white hole?

I think Roger Penrose’s explanation here is appropriate, but I don’t know if the similarity between a black holes evaporation and the eventual entropy death of the universe are similar enough: https://youtube.com/watch?v=z2_6h15UCMg.

If so, I think it would mean a Plankt scale black hole would have a significant probability of spontaneously evolving a white hole?

Re: Black Hole Evolution Traced Out with Loop Quantum Gravity

#13
post #12
post #9

Earlier quoted context omitted.

Yes, but the event horizon shrinks by emitting Hawking radiation, right? When the white hole is exposed, what it looks like? Is it just hole in the space that does not emit anything? Nothing exits (because Hawking radiation already emitted all of the energy) and nothing can enter. What is the radius of the white hole?

I think Roger Penrose’s explanation here is appropriate, but I don’t know if the similarity between a black holes evaporation and the eventual entropy death of the universe are similar enough: https://youtube.com/watch?v=z2_6h15UCMg . If so, I think it would mean a Plankt scale black hole would have a significant probability of spontaneously evolving a white hole?

I just listened Sean Carrol's podcast interview wit Penrose and I think they are different. https://www.preposterousuniverse.com/podcast/2019/01/07/epis...

In the loop quantum gravity there is a bounce because at the lowest level spacetime is discrete and can't be compressed. The big bounce theory of relating to big bang in the loop quantum theory might be similar to the black hole/white hole theory.

In Penrose's theory it's the gravity/mass that is creating time and clumping things together between the big bang and the heat death of the universe (you need mass to create clock and time).

At the beginning of the universe temperature was so high that masses did not matter, at the end of the universe there is no mass, just massless particles (after googol or so when the biggest black holes have evaporated). Massless particles (photon, gluon, graviton) don't experience time so they in a sense fly into the the end of the eternity instantly.

Then there is something geometrical I don't understand and the ends meet and the new universe matches the end of the previous across timeless eon.

Penrose thinks you could perceive the ripples caused by the massive black holes from the last universe in the background radiation of our universe.

Re: Black Hole Evolution Traced Out with Loop Quantum Gravity

#14
My quick summary of white holes, which I thought were a product of science fiction:

Predicted by some solutions to relativity.

They have not been observed yet but recent theories suggest that some burst of gamma rays may be markers.

Other theories suggest that the expulsion of matter from a white hole may occur very quickly, almost instantaneously, so unlike say a supernova you’d need to be looking at the right place and the right time to see it happen.

White hole mass may be behind a horizion that makes them dark = dark matter.

Our Big Bang may have been a super-massive white hole event, so we are a universe-within a universe.

Re: Black Hole Evolution Traced Out with Loop Quantum Gravity

#15
Is there evidence for or against the interior of black holes being similar to distinct separate universes? Is that a popular idea at all, in physicists' circles?

How much (and _what_) would I need to read and understand to get a feeling of the nature of black holes?

I'm a total layman when it comes to physics and it would put some distant worries of me to rest.

I'd rather measure a lot of Hawking radiation while throwing bottles in flasks into a black hole. However, I'm currently preoccupied with figuring out why my mouth keeps talking when I'm not thinking of anything.

Re: Black Hole Evolution Traced Out with Loop Quantum Gravity

#16

My quick summary of white holes, which I thought were a product of science fiction: Predicted by some solutions to relativity. They have not been observed yet but recent theories suggest that some burst of gamma rays may be markers. Other theories suggest that the expulsion of matter from a white hole may occur very quickly, almost instantaneously, so unlike say a supernova you’d need to be looking at the right place…

Has anyone tried sending information into black holes using lasers yet?

It'd be convenient if ET's only lived in black holes, although perhaps a little lonely, too.

Re: Black Hole Evolution Traced Out with Loop Quantum Gravity

#17
post #13
post #12

Earlier quoted context omitted.

I think Roger Penrose’s explanation here is appropriate, but I don’t know if the similarity between a black holes evaporation and the eventual entropy death of the universe are similar enough: https://youtube.com/watch?v=z2_6h15UCMg . If so, I think it would mean a Plankt scale black hole would have a significant probability of spontaneously evolving a white hole?

I just listened Sean Carrol's podcast interview wit Penrose and I think they are different. https://www.preposterousuniverse.com/podcast/2019/01/07/epis... In the loop quantum gravity there is a bounce because at the lowest level spacetime is discrete and can't be compressed. The big bounce theory of relating to big bang in the loop quantum theory might be similar to the black hole/white hole theory. In Penrose's the…

I think it’s like a duality or equivalence through asymptotic states. Ie old universe becomes timeless energy and new univese.

Re: Black Hole Evolution Traced Out with Loop Quantum Gravity

#18
post #17
post #13

Earlier quoted context omitted.

I just listened Sean Carrol's podcast interview wit Penrose and I think they are different. https://www.preposterousuniverse.com/podcast/2019/01/07/epis... In the loop quantum gravity there is a bounce because at the lowest level spacetime is discrete and can't be compressed. The big bounce theory of relating to big bang in the loop quantum theory might be similar to the black hole/white hole theory. In Penrose's the…

I think it’s like a duality or equivalence through asymptotic states. Ie old universe becomes timeless energy and new univese.

LQG and big bounce requires big bang and expansion being followed with contraction of the universe ending with big crunch at the end.

Pernroses CCC (conformal cyclic cosmology) is a big bang followed by an infinite future expansion and timelike infinity.

Re: Black Hole Evolution Traced Out with Loop Quantum Gravity

#19

My quick summary of white holes, which I thought were a product of science fiction: Predicted by some solutions to relativity. They have not been observed yet but recent theories suggest that some burst of gamma rays may be markers. Other theories suggest that the expulsion of matter from a white hole may occur very quickly, almost instantaneously, so unlike say a supernova you’d need to be looking at the right place…

Has anyone tried sending information into black holes using lasers yet? It'd be convenient if ET's only lived in black holes, although perhaps a little lonely, too.

"Has anyone tried sending information into black holes using lasers yet?"

We would need one at a pretty uncomfortably close distance to perform this experiment in acceptable time and without needing insanely large amounts of energy.

Makes me wonder how close the next known black hole is. The center of the milky way?

Re: Black Hole Evolution Traced Out with Loop Quantum Gravity

#20

My quick summary of white holes, which I thought were a product of science fiction: Predicted by some solutions to relativity. They have not been observed yet but recent theories suggest that some burst of gamma rays may be markers. Other theories suggest that the expulsion of matter from a white hole may occur very quickly, almost instantaneously, so unlike say a supernova you’d need to be looking at the right place…

Has anyone tried sending information into black holes using lasers yet? It'd be convenient if ET's only lived in black holes, although perhaps a little lonely, too.

> The closest black hole we know of is V616 Monocerotis, also known as V616 Mon. It's located about 3,000 light years away. [1]

So no, because we haven’t had lasers for 3000 years yet, and the black holes we can create here on earth last for microseconds.

[1] https://phys.org/news/2016-03-closest-black-hole.html

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