Thread: Could fluctuations for a BH singularity create uncertainty at its EH?

Could fluctuations for a BH singularity create uncertainty at its EH?
Lets say that the exact position of the BH singularity could fluxuate by lets say a plank legnth. Wouldnt that be enough for the EH not to be smooth?

Please don't use acronymns. They are very confusing. If you mean "black hole", then say so; if you mean "event horizon", then say so. And check your spelling please. Thank you.

Originally Posted by Warren Chu

Please don't use acronymns. They are very confusing. If you mean "black hole", then say so; if you mean "event horizon", then say so. And check your spelling please. Thank you.

Could fluctuations for a black hole singularity create uncertainty at its event horizon?
Lets say that the exact position of the black hole's singularity could fluxuate by lets say a plank legnth. Wouldnt that be enough for the Event horizon not to be smooth?

As far as I know, the EH is far from smooth, quantum fluctuations are the norm. However, adressing the EH in terms of normal particles doesn't really make a whole lot of sense, things like distance and space, even past and future are very different at the EH.

For this to be significant, the black hole would have to be "extremal" (i.e. just about the smallest it could be before being annihilated by Hawking radiation).

At one time I looked at what the maximal radius of an electron massed, electron charged black hole (i.e. using geometrized_units and the Kerr-Newman metric) was something like 10^-53 m, which is much, much smaller than the Plank length. The point is that this is about as extremal as you can get in terms of a black hole (unless it is a single electron neutrino or a photon that is the last remaining member of the singularity!)

So, if it is "extremal" you can bet that normal quantum fluctuations are going to play a big part in the properties of the "BH".

My gues is the event horizon has bumps and lumps, and changes radius.. More infalling mass increases the radius. As this mass moves from just inside toward the center the event horizon radius decreases slightly. This because a real black hole is not a point source. Neil

It's because the fluctuations at the BH's event horizon aren't caused by the BH itself. Rather, those fluctuations, known as particle-pair creation and annihilation occur all the time throughout normal space. It's part of the "quantum foam" fluctuation aka "zero-point energy," and is why vacuum itself has a temperature.

Just as they're created, however, on Planck unit of time later those particles self-annihilate, leaving behind... nothing.

But what happens when one of those particles is sucked into the BH while the other escapes? What then? Is the BH's mass increased or decreased?

Hawking says that since there is no such thing as a negative mass particle, that positive mass is radiated from the BH since entropy must be preserved and the BH mass decreases. On the other hand, if there is no such thing as a negative mass particle, then the other particle in the pair which was pulled into the BH must be increasing, not decreasing, the BH's mass.

So where did the mass come from? Was it simply created from nothing? Is it contributing to the cosmological constant in some way, or inflation? Perhaps its the source of dark matter, and that most BH's are 70% more massive than we think they are (or are simply that much more numerous) because mass really is created by the combination of quantum fluctuation and particle-pair production.