Wheeler's 1940 'One-Electron Universe' Idea Shaped Feynman's Physics
Physicist John Wheeler proposed to Richard Feynman in a 1940 phone call that every electron and positron in existence could be a single particle tracing a tangled path back and forth through time. Sections of this path moving forward in time appear as electrons, while sections looping backward appear as positrons. Physicist E. C. G. Stueckelberg independently arrived at a similar concept around the same period.