Werner Heisenberg
Werner Heisenberg formulated quantum mechanics in its first complete form and stated the uncertainty principle, and led Germany's wartime nuclear research. Born in Würzburg in 1901 to a professor of Greek, he studied under Arnold Sommerfeld in Munich, where he nearly failed his doctoral examination in 1923 after being unable to answer a question about how a battery works. In June 1925, suffering from hay fever, he retreated to the island of Helgoland and worked out a formulation of quantum theory using only observable quantities — the frequencies and intensities of spectral lines — rather than unobservable electron orbits. Max Born recognised that the arrays he had produced were matrices, and matrix mechanics followed. He was twenty-three. In 1927 he published the uncertainty principle: the position and momentum of a particle cannot both be known precisely, and the more exactly one is determined the less exactly the other can be. It is a property of nature rather than a limit of instruments, and with Bohr's complementarity it forms the Copenhagen interpretation. He received the Nobel Prize in 1932. He stayed in Germany after 1933 and was attacked in the SS press as a white Jew for teaching relativity, an accusation resolved only after his mother appealed to Heinrich Himmler's mother. He led the German nuclear programme from 1939. It never came close to a weapon, and whether that was incapacity or reluctance is still argued. His 1941 meeting with Bohr in Copenhagen ended the friendship and remains unexplained; it is the subject of Michael Frayn's play. Secretly recorded at Farm Hall in 1945, he was audibly astonished at Hiroshima. He rebuilt German physics after the war and died in 1976.
- Lived: 1901 CE – 1976 CE
- Nationality: German
- Roles: scientist
