>>12686013Alright, so in particle physics the most important thing is conservation. Energy, charge, spin, and so on, are all conserved. What that means is that, if I draw a bubble around two particles it doesn't matter what happens between those two, the total charge/energy/etc inside that bubble will stay the same.
Now let's have a photon. It's flying through space. I draw a bubble around it. That photon can turn into an electron-antielectron pair. The overall charge is zero, the extra mass comes from the energy of the photon, the spins add up to one, etc. This is allowed, has been shown to happen, and is the reason light coming in from really far away galaxies takes very slightly longer than would otherwise be expected. Everything is fine, since the total energy/charge/spin/etc is the same.
Now, let's have that photon pass really,really, really close to a black hole's event horizon. Close enough so that when it splits into an electron-antielectron pair, one of those two falls in. The other one can still escape.
If we draw the bubble around both the blackhole and this newly freed electron, the overall charge, energy, etc is still the same.
BUT. since the anti-electron fell in, it can no longer meet back up with the electron to annihilate and turn back into a photon. To the rest of the universe, this photon passing by a black hole just turned into an electron.
That escaping electron carries away energy gained from the black hole (think of slingshot trajectories with NASA probes).
Thus the electron can be thought of as 'radiating away' from the blackhole, and reducing it's mass-energy very,very slowly.
