I’m talking about what I’ve read of the Hawking radiation (HR). This is said to be generated by the vacuum energy in the immediate surroundings of the events’ horizon (EH) which includes any balck hole. It is said that if a pair of virtual particles comes to a real existence in that space, it may happen that one of them crosses the EH and falls within the black hole. At this point, in order to satisfy the energy conservation principle (ECP), the particle in the black hole subtracts an amount of mass, equal to its own, while the other companion particle remains real in the outer space, thus giving rise to an apparent emission of particles/energy by the black hole. That’s the way a blak hole evaporetes.

Now, it looks like we can split the entire process in three stages.

- A pair of virtual particles is created and, according to the uncertainty principle, it can persist for a time Δt, no longer than h/4πmc
^{2}, where m is the mass of any of the two particles. - By chance one of the two particles falls into the black hole and desappears from the outer space.
- The mass of the black hole decreases of exactly the same amount of the incoming particle.

A small amount of the black hole mass has desappeared! Why not the mass of the incoming particle? If one insists on the former hypotesis then he is forced to postulate a decisive interaction between the particle and the stuff of the black hole. It’s not a mass-anti-mass annihilation. It remains the idea of the particle mass changing sign preceding the annihilation against the positive matter of the balck hole.

The novelty here is the idea of a negative mass. To my opinion, the introduction of such an idea into the crucible of Physics is as alarming and of course as fashinating at least as the one allowing for an exceptional violation of the energy conservation principle (ECP), due to the extreme *singularity* of an object such as a black hole.

**Perhaps they are both wrong.**

Unless there is a third possibility the former ones are mutually exclusive. Either there is a change of sign of the particle gulped down by the black hole, or there is a permanent violation of the ECP thereby increasing the mass of the black hole and the mass present in the outer space. Both alternatives seem confined within the realm of the black holes. In fact nowhere else has ever been seen a permanent violation of the ECP, and the same is sure about the negative mass. No one has ever observed the creation from nothingness of pairs of positive and negative masses of any size, which, by the way, could remain real for ever, being the ECP not disturbed at all.

Does a negative mass exert a negative gravitational field? If so it could be repelled by the black hole with fantastic accelerations. That is perhaps why it is easier to think that the sign change happens within the black hole and necessarily well deep into its mass, in order to have a “1” probability to strike a positive mass, otherwise it would be spit away across the EH… perhaps as the only way anything could really emerge from a black hole.

There is another concept which must be dragged into this business: the entanglement. In any case, the two particles of the pair must necessarily be entangled even if each on the opposite sides of the EH.

To sum up, I see two simpler alternatives to HR:

Being the two particles entangled, why not suppose that after the maximum allowed Δt, they simply and plainly desappear and the black hole remains unperturbed?

If it’s true that in the void space there is generation of particles pairs, why not suppose a disentaglement across the EH of a black hole thus making it a matter generating machine?

The latter is the more fashinating, of course, but the former much simpler.