Which brings me to something that has puzzled me. As I understand things, if a photon exists it travels at the speed of light. Given an excited atom when an electron falls to a lower energy level a photon is emitted. Is it going at the speed of light at the instant of creation? And what accelerated it to that speed? Is this one of those things that just is?
If anyone cares here’s my simplified explanation of Hawking radiation.
Virtual particles are not real particles. They exist on borrowed energy and must quickly annihilate and repay this energy. However, the extreme tidal gravitation of a BH can pull them apart with enough force that they gain enough energy to become real long lived particles and at the same time pay back the energy debt to the nearby negative energy regions of space.
So when the hole captures one of these now real particles, it in effect radiates the other one. It has therefore supplied enough energy to create two particles, but only gets the energy of one back. Thus it loses mass. (Warning: Hawking Radiation is actually much more complicated than this, however I only understand it at this level.)
There’s no real “acceleration” like you’re thinking of from classical mechanics. It basically just happens, as we understand it.
Actually, think of it as three particles (un)colliding. There’s an electron and a photon going out from the collision into the future, and you’d say there’s an electron coming in from the past. I’d say it’s a positron (anti-electron) going out to the past. Anyhow, as long as various numbers line up – the spins, the 4-momenta, the charges… – the particles are allowed to interact.
So if we go back to the electron-emits-a-photon picture, the photon is just made from the loss of 4-momentum in the electron, and all of that 4-momentum goes into “kinetic energy”. It isn’t accelerated to the speed of light, it just travels at that speed from the get-go. That just what photons do.
First of all virtual particles aren’t on the mass shell which means that m[sup]2[/sup] = E[sup]2[/sup] - p[sup]2[/sup] doesn’t apply, and secondly they’re created and made real outside the event horizon so if one of them has enough energy it can escape. This is allowed as long as the other has equal and opposite momentum.
That’s what I suspected. It just is, at least so far.
Oh I semi understood your post. Well, since you said you semi understood maybe I only hemi-semi understood. 
the last read I did from Hawking on the subject has him stating that the information is lost. while it can be emitted again it will have no memory or relationship to the energy that went into the hole in the first place.
An odd post of an odd fact.
One of the stranger aspects of Hawking radiation is that it can both exist and not exist depending on whether the observer is hovering above the horizon or free falling into it. In the first case the horizon appears as a hot radiating thermodynamic membrane and in the second it’s nothing at all.
But that’s hardly stranger than the Unruh effect. Surprising when it’s first pointed out to you. Ultimately pleasingly consistent.
But there are obviously some differences (as I know you’re fully aware). For instance, an inertial observer can see past the Rindler horizon, and Rindler spacetime is globally flat whereas any true gravitational phenomenon (say, a BH) necessarily involves spacetime curvature.
Bonzer please don’t think I’m trying to tell you something you don’t already know; I’m well aware you are a googleplex more knowledgeable than I will ever be.
Sorry! Erroneous Posting! Sorry! :eek: