If someone could shed some light so that I can think straight again that would be appreciated..

Anywho, since watching a video on what the universe may look like in trillions of years (each atom being distant to each other by light years, all black holes ultimately evaporating) and knowing that that blackholes have an extreme time dilation effect, I’m wondering if the matter that enters a blackhole (or timehole as I’d like to call them now) is teleported through time and come out when the black hole evaporates in that distant, extremely dark universe. As opposed to being stuck for an inifinite amount of time.

I’m no physics major or anything, just intrigued by some things. If this is easily answered by what is observable by micro-blackholes then too easy.


1 Answer 1


"...if the matter that enters a blackhole [...] is teleported through time and come out when the black hole evaporates in that distant, extremely dark universe."

Probably not. A BH (black hole) can emit all sorts of particles via Hawking radiation, but the odds are that most of the emitted particles are photons. For stellar mass & larger BHs, those are very cold microwave photons corresponding to temperatures around a billionth of a degree above absolute zero, and even colder for the big ones at the cores of galaxies. And the emission rate is also microscopic, so even if we had a BH for convenient observation in our solar system we'd have great difficulty detecting its Hawking radiation.

If you want to play with the numbers, take a look at the Hawking radiation calculator by Viktor Toth.

Of course, in the present era all such BHs are much colder than the CMB (cosmic microwave background), so they absorb more radiation than they emit. In the far future, when the CMB is less than $10^{-9}K$, and the BHs get a chance to lose mass via evaporation, then they may emit the occasional electron or other low mass particle along with the photons.

Bear in mind that we need a working theory of quantum gravity to give proper answers to questions about what happens inside BHs. Even Hawking radiation is a bit shaky, theory-wise. For that matter, we still don't have first-class observational evidence that BHs exist, although we're fairly confident of lots of BH candidates, and if they aren't actually BHs, then they must be even weirder. :)

But anyway, we're fairly sure that normal matter cannot exist inside a BH. It gets spaghettified on its way to the BH core (which may or may not be a mathematical singularity); even atoms get ripped to pieces. We don't know what actually happens at the core, but many theorists expect that some quantum effect prevents the core from having zero volume. See Ben Crowell's description of what a BH singularity is like, according to current (non-quantum) general relativity.

So a BH core is very unlikely to preserve matter as we know it, and when a BH evaporates, it mostly emits photons, at a very slow rate... until it gets small enough to evaporate explosively. But as I said above, we don't yet have a working theory that we can use to model the final phase of Hawking radiation, so who knows what can happen then. ;)

Your question mentions micro-black holes. It's possible that such things were created in the very early universe, but if so, we haven't seen any evidence for them (like gamma ray blasts of Hawking radiation as they die). And we have looked for them, since they're a possible dark matter candidate. We don't know any process that could produce them in the present era. There was talk a few years ago that they might be made in a collider like the LHC, but only if certain non-standard gravity theories were correct. It was unlikely then, and since then various other observations have made such theories even less likely,

  • $\begingroup$ Thank you PM. More to think about now. If BH break down atoms to their particles, or the particles into pure energy (don’t know if that is even real) an you say something could be stopping a pure singularity, do you think that the inside of a blackhole could be true Absolute Zero, that the matter-energy inside is frozen in a sort of crystal? $\endgroup$
    – JSI24
    Commented Nov 7, 2018 at 13:41
  • $\begingroup$ Also that maybe the reason such small amounts of photons escape is because maybe they don’t have a rigid position available within that frozen object $\endgroup$
    – JSI24
    Commented Nov 7, 2018 at 13:49
  • $\begingroup$ @JSI24 Photons never have a rigid position, they always move locally at $c$. It's hard to understand what happens inside a BH because spacetime there is so radically different. Photons don't actually escape from inside a BH, Hawking radiation emits stuff from just outside the event horizon. $\endgroup$
    – PM 2Ring
    Commented Nov 7, 2018 at 14:11
  • $\begingroup$ Pm do photons move at c at AZ? $\endgroup$
    – JSI24
    Commented Nov 7, 2018 at 18:18
  • $\begingroup$ @JSI24 AZ = absolute zero? Absolute zero is (probably) unreachable. But photons always move at $c$. $\endgroup$
    – PM 2Ring
    Commented Nov 7, 2018 at 18:23

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