““To sum up: Electron and positron annihilate as a pair, in a particle-antiparticle collision. Their energy heats up the vacuum; when the hot vacuum decays, real particles emerge. The annihilation energy of electron and positron has, in the process, been used to realize the hidden faculties of the vacuum. For individual cases, the results may be muon-antimuon pairs, quark-antiquark pairs, and so on. In passing through the intermediate state of an excited vacuum, it looks as though the electron and positron actually knew which virtual particles their annihilation might realize. But in fact, electrons and positrons in themselves are pointlike, and can be fully described in terms of a theory that knows neither muons nor quarks. So it is not the electron and the positron that "know" the possible final products of their interaction- it is the intermediate state, our vacuum, that has that knowledge.””
