Ludwig Boltzmann (1844 - 1906) Austria
Ph.D. from the University of Vienna in 1866 under Josef Stefan. Studied under Helmholtz in Heidelberg. Was chair of theoretical physics at Graz, chair of mathematics at Vienna, chair of experimental physics back at Graz and finally chair of theoretical physics at Vienna. He developed the statistical model of entropy, derived the theorem of equipartition of energy (Maxwell-Boltzmann distribution of energy), and the theory of blackbody radiation. Boltzmann was plagued with manic-depressive behavior, and hung himself in 1906 while on vacation with his wife and daughter.