I'm pretty much a newby to the ins and outs of QED and have a question about antiparticles. First: stop me if I'm wrong... Antiparticles can be thought of as (or simple are?) normal particles moving backwards in time. Experiments have shown photons splitting into electron-positron pairs followed by the positron annihilating with an electron to reproduce a photon leaving only the seemingly brand-spanking new electron. QED says what's really going on is an electron is emitting a photon, moving backwards in time, emitting another photon (that itself travels backwards in time) and moving forwards in time again. This view surely necessitates that every antiparticle in the universe is predestined to annihilate with a particle, because travelling backwards in time that annihilation is the very origin of that antiparticle. Is this right?