A member of the NIST staff since 1977 and a Senior NIST Fellow in the Materials Science and Engineering Laboratory since 1984 , Cahn has played a critical role in the scientific life of our organization. His unwavering insistence that scientific work be compatible with the fundamentals of thermodynamics has greatly strengthened the rigorous scientific underpinning of research throughout NIST. In his search for knowledge, John has reached out to scientists in diverse fields and has stimulated them to work on a broad range of materials problems. The solutions to these materials problems have led directly to the creation of modern, multifunctional materials.