Black Hole Evolution Traced Out with Loop Quantum Gravity
physics.aps.org
physics.aps.org
1. Black hole gradually evaporates (Hawking radiation) until it's Plank size.
2. Quantum transition and Plank star.
3. White hole is formed and "the collapsed star is bouncing back".
I Always thought that black hole evaporating energy as Hawking radiation contains all the energy that went into the black hole when the evaporation is complete. This theory assumes that there is energy left.
How is the total energy that went in is distributed between the Hawking radiation and the white hole that follows the evaporation?
Are all white holes equal in size and does Hawking radiation account for the black hole size difference?
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?
If so, I think it would mean a Plankt scale black hole would have a significant probability of spontaneously evolving a white hole?
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.
Pernroses CCC (conformal cyclic cosmology) is a big bang followed by an infinite future expansion and timelike infinity.
It's seems like it must be either Hawking radiation OR white hole bounce not both.
If Hawking radiation evaporates the black hole then there should be no matter or energy left for white hole to ouput in the future.
I take this to be an interesting technical advance for a theory whose relevance in general is still an open question.
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.
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.
It'd be convenient if ET's only lived in black holes, although perhaps a little lonely, too.
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?
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.
Getting information back about the success of the effort is... challenging.
Our Big Bang "may have been"
a super-massive white hole event,
"so we are" a universe-within a universe.
You need to revise the "so we are" into "so maybe one might imagine we could be" in light of the "may have been" part.
But taken as granted, let's just say the big bang actually happens to have been what you describe.
The first thing that such a hypothesis would reveal is that in such a scenario, the big bang we consider to be as an event of origin and the beginning of "space/time" suddenly is not at all the beginning of anything. It is no longer the origin of the universe. Now, there was something prior to it.
Second, if we look upone the universe, as it exists today, we find many super-massive black holes. At this point it becomes clear, that there are likely to be, or to have been just as many super-massive white holes. All contemporary, and all distributed in a similar fashion.
If there's one, there's another somewhere else. Just like we see with galaxies, or exotic stars, or exoplanets. If there's one, there's another somewhere else. So too for white holes.
Thus, even if the big bang, which we see as evidence in the cosmic background radiation, remains the most recent grand-daddy and mother of all cosmic events in the past 20 billion years, it cannot be assumed to be unique in THIS unerverse, and in THIS space-time continuum.
We can only draw the conclusion that in this very universe, there may have been another super-massive white hole event, prior to even the big bang, just as transformative in the distribution of mass and energy, and not only that, there will be a similar cataclysmic white hole event in the future, perhaps beyond the era of humanity as we know it, whether we continue to reside in this solar system and galaxy or not.
So, multi-verses are not a necessary conclusion to draw from white hole events, because there's nothing stopping total creation and total destruction and then total recreation from occurring and reoccurring in the same universe we seem to be in right now, simulation or not.
Taking a Photograph of a Black Hole
Einstein’s Shadow:
https://www.amazon.com/Einsteins-Shadow-Black-Astronomers-Un...
Because one part of a pair of virtual particles crosses the horizon, and the other one does not, they become separated by said horizon and cannot recombine and disappear. The particles become actual and not virtual, but one is lost to the hole. Hence, it looks to the external world as if a particle was emitted by the hole.
Note that to my (layman's) knowledge, this has not been actually observed, but does seem to be a modern consensus and involved a paid bet.
Ultimately, hawking radiation does not come from within the event horizon, so it can escape into the wider universe.
For a more detailed answer with references, see the last answer here at https://physics.stackexchange.com/questions/89983/how-many-o... .
Black wholes and white holes would then be gateways to other universes.
Multi verse https://en.wikipedia.org/wiki/Multiverse
https://news.nationalgeographic.com/news/2010/04/100409-blac...