Source: cirosantilli/positrons-are-electrons-travelling-back-in-time
= Positrons are electrons travelling back in time
TODO understand this stuff:
* https://physics.stackexchange.com/questions/144607/are-all-positrons-electrons-traveling-back-in-time
* https://www.quora.com/Is-a-positron-just-an-electron-going-backwards-in-time?share=1