Pair creation and annihilation and Wheeler's one electron universe

Question

I stumbled upon Wheeler's idea that there could be only one electron. If I understood correctly, basically the idea is that one electron moves forward and backward in time such that it appears as if there are many electrons and positrons. Of course there will have to be as many positrons as electrons and this cannot explain why there are many more electrons than positrons around.

Nevertheless taking inspiration from this idea I wondered whether it is possible to interpret a pair creation of electron and positron followed by pair annihilation as one electron moving in a timeloop continuously absorbing and emitting photons.

Answer 1

I wondered whether it is possible to interpret a pair creation of electron and positron followed by pair annihilation as one electron moving in a timeloop continuously absorbing and emitting photons.

This phenomenon actually exists and is called vacuum polarization. You can imagine it as one electron moving in a loop, as visualized by the following Feynman diagram. However, it doesn't mean that an infinite number of photons is absorbed and emitted.

It just means that a traveling photon occasionally can turn into an electron-positron pair, and a short time later the pair turns back into a photon again.

There are other processes also involving a closed electron-loop.

The Feynman diagram below describes photon-photon scattering. Two photons create an electron-positron pair, and this pair annihilates giving two photons again.