Janus said:It isn't the collision of between particles, but a creation of a pair of particles. Quantum fluctuations create a matter/antimatter pair of particles at the event horizon. Occasionally, one of the two falls into the event horizon before they can recombine. The other particle leaves.
Since the creation of the pair came from "borrowed" energy, the energy needed to maintain the existence of this particle must have come from somewhere. That somewhere is the mass of the black hole. To balance the energy books, the particle that falls into the black hole has a negative mass, and actually reduces the mass of the black hole. The result is that you see particles leaving the vicinity of the black hole while the black hole loses mass.
TalonD said:1 Isn't there such a thing as quantum vacuum energy? like in the casimir experiment?
2 don't these pairs of particles pop into existence everywhere, even very far away from any black hole or other mass?
3 so where does that energy come from?
4 or do the equations still balance out because the particle anihilate and go back to nothing?
5 and if it is a particle/antiparticle pair then would they not emit some energy gama ray or something when they anihilate?
Dmitry67 said:1 Yes, Casimir effect is explained by the virtual particles
2 Yes
3 From nowhere, virtual particles don't carry any free energy. They violate energy conservation law for small periods of time (obeying HUP)
4 yes, they go back to nothing because they don't carry free energy
5 and for that very reason they don't radiate - they don't have energy
The only difference near the horizon is horizon breaks the pairs, preventing the annihilation.
jnorman said:how can being near the EH of BH break up the pairs? if they do not come into existence with an enormous amount of velocity (near C), neither particle could ever escape from the gravity well of the BH.
Hawking radiation is a theoretical concept proposed by physicist Stephen Hawking in 1974. It suggests that black holes emit a type of radiation due to quantum effects near the event horizon, the point of no return for a black hole.
Hawking radiation is thought to occur when a pair of virtual particles, one with positive energy and one with negative energy, is created just outside the event horizon of a black hole. The negative energy particle falls into the black hole while the positive energy particle escapes, resulting in a loss of mass for the black hole.
While direct observation of Hawking radiation is not yet possible, there is strong theoretical and indirect evidence for its existence. This includes the laws of thermodynamics, which predict that black holes should emit radiation, as well as observations of black hole candidates that show they are losing mass over time.
Yes, according to the theory, Hawking radiation can cause a black hole to lose mass over time and eventually evaporate completely. However, this process would take an extremely long time for large black holes, and for most black holes in the universe, the rate of radiation emission is very small compared to the rate of matter being pulled into the black hole by gravity.
In theory, yes, Hawking radiation could be harnessed as a source of energy. However, the amount of energy emitted by a black hole through Hawking radiation is very small and not practical for our current technology. Additionally, the process of extracting this energy would require advanced technology and would likely have negative effects on the black hole itself.