Arthur Compton

Chronicled events

1. 1923​·​X-Rays Bounce Like Billiard Balls
   #5831

   X-rays bounced off electrons come back with longer waves, the longer the more sharply they’re deflected. A wave would come back with its wavelength unchanged. The shift is just what it should be if each quantum collides with a single electron, like one billiard ball with another.