Hans Albrecht Bethe (1906–2005) first explained the process of nuclear fusion. Born in Strasbourg, Germany, he studied in Britain and the United States, then joined the physics faculty of Cornell University in 1935. There he worked on the theory of how quantum mechanical systems operate at high temperatures. In May 1938, Bethe published his findings explaining how nuclear fusion could work at the heart of the Sun, and how it could produce enough energy to make the Sun shine. Bethe’s work in theoretical nuclear physics made him particularly valuable in the development of the first atomic bomb. He was deeply involved in the Manhattan Project during World War II, and was one of the pioneering scientists to work at Los Alamos National Laboratories in New Mexico. After the war, he continued to conduct pioneering research in the physics of stars and the processes that go on inside them. For his immense contributions to science, Hans Bethe was awarded the Nobel Prize in Physics in 1967.