Credit: Copyrights: Jan Gieseler; Image of H. Kramers courtesy of AIP Emilio Segrè Visual Archives, Goudsmit Collection
In 1940, Hendrik Kramers (left) predicted theoretically that in a double-well system (center bottom) transitions between the stable states happen most frequently at intermediate friction (upper right). The background shows a detail of the laser system used to confirm Kramers’ prediction experimentally.