See also: 1920 in science, other events of 1921, 1922 in science and the list of years in science.
Chemistry Thomas Midgley discovers the effective anti-knocking properties of Tetra-ethyl lead, which is used in "leaded" gasoline (petrol). Medicine July 18 - The first BCG vaccination against tuberculosis. July 27 - Researchers at the University of Toronto led by biochemist Frederick Banting announce the discovery of the hormone insulin. Physics T. Kaluza demonstrates that a five-dimensional version of Albert Einstein's equations unifies gravitation and electromagnetism. Awards Nobel Prize Physics - Albert Einstein Chemistry - Frederick Soddy Physiology or Medicine - not awarded Births May 21 - Andrei Sakharov, physicist, human rights activist, Nobellaurette in Peace (+ 1989) Deaths
