The one-electron universe hypothesis, commonly associated with Richard Feynman when he mentioned it in his Nobel lecture, postulates that there exists only a single electron in the universe, propagating through space and time in such a way as to appear in many places simultaneously.
Feynman’s thesis advisor, John Wheeler, proposed the hypothesis in a telephone call to Feynman in the spring of 1940. He excitedly claimed to have developed a neat explanation of the quantum mechanicalindistinguishability of electrons:
As a by-product of this same view, I received a telephone call one day at the graduate college at Princeton from Professor Wheeler, in which he said, “Feynman, I know why all electrons have the same charge and the same mass” “Why?” “Because, they are all the same electron!” And, then he explained on the telephone, “suppose that the world lines which we were ordinarily considering before in time and space—instead of only going up in time were a tremendous knot, and then, when we cut through the knot, by the plane corresponding to a fixed time, we would see many, many world lines and that would represent many electrons, except for one thing. If in one section this is an ordinary electron world line, in the section in which it reversed itself and is coming back from the future we have the wrong sign to the proper time—to the proper four velocities—and that’s equivalent to changing the sign of the charge, and, therefore, that part of a path would act like a positron.” “But, Professor”, I said, “there aren’t as many positrons as electrons.” “Well, maybe they are hidden in the protons or something”, he said.—Feynman, Richard, Nobel Lecture December 11, 1965