Ernst Ising (born May 10, 1900, Cologne Germany – May 11, 1998, Peoria, Illinois) was a German physicist, who is best remembered for the development of the Ising model of ferromagnetism. He was a professor of physics at Bradley University until his retirement in 1976.
Ising earned a Ph.D in physics from the University of Hamburg in 1924. His doctoral thesis studied a problem suggested by his teacher, Wilhelm Lenz . He investigated the special case of a linear chain of magnetic moments, which are only able to take two positions, "up" and "down," and which are coupled by interactions between nearest neighbors, a model which came to be known as the famous Ising model.