Where Have All the Positrons Gone?

 In the beginning the Universe was presumably populated by positrons, electrons, protons, neutrons, etc. The positrons combined with electrons and there was light. But the protons and neutrons were competing with the positrons, forming atoms which had no external electric fields with which to attract positrons. A significant fraction of the free electrons were “hidden” in the newly formed atoms, leaving little for the positrons to be attracted to. Repelling other positrons, they fled the newly formed Universe of atoms, and continue to flee to this day into infinite space, far beyond our ability to see. They are relatively scarce here in the visible Universe where we can detect them. But hypothetically an enormous swarm of them is still out there in infinite space, fleeing away in every direction!

Author’s note: This scenario is dedicated to my daughter, who asked me (after looking at the Stable Positron article) “Where are all the positrons, Dad?”