John W. Cahn

John Werner Cahn (January 9, 1928 – March 14, 2016) was an American scientist and recipient of the 1998 National Medal of Science. 
He was a professor in the department of Materials Science at MIT from 1964 to 1978. Since 1977, he has held a position at the National Institute of Standards and Technology (formerly the National Bureau of Standards, NBS).Cahn has applied the basic laws of thermodynamics to describe and predict a wide range of physical phenomena.