James Franck

Origins and early life

James Franck was born in Hamburg on 26 August 1882, the second child of Jacob Franck, a banker, and of Rebecca Nachum Drucker, and went to school at the Wilhelm-Gymnasium there. He was born into a Jewish family, with a devout father and a mother descended from rabbis, and although he was not religious himself, he remained proud of his Jewish heritage. At Heidelberg he met Max Born, who became a lifelong friend, and he took his doctorate in physics at Berlin in 1906 under Emil Warburg.

Work and career

In 1914, in Berlin, he and Gustav Hertz showed that electrons striking mercury atoms lose energy only in fixed amounts, early experimental support for Niels Bohr's model of the atom. From 1920 he directed the Second Institute for Experimental Physics at the University of Göttingen, which he and Born made one of the great centres of physics until 1933, and his work on molecules gave rise to the Franck–Condon principle.

He and Hertz shared the Nobel Prize in Physics for 1925, presented in December 1926, for their discovery of the laws governing the impact of an electron upon an atom. On 17 April 1933, although exempt as a veteran of the First World War, he resigned in protest against the law that drove Jewish civil servants out, the first academic to do so, and he helped dismissed Jewish scientists find posts abroad before leaving Germany that November.

After a year with Bohr in Copenhagen and three at Johns Hopkins, he moved in 1938 to Chicago, where he turned to photosynthesis, led the chemistry division of the Metallurgical Laboratory and chaired the committee whose report of 11 June 1945 urged that the atomic bomb not be used on Japanese cities without warning.

Later years

He died of a heart attack on 21 May 1964 while visiting Göttingen, which had made him an honorary citizen, and in 1967 the University of Chicago named its James Franck Institute after him.