1903-1976

Norwegian-born, American chemist who won the Nobel Prize in 1968 for his theory of irreversible chemical reactions. He made significant contributions to statistical mechanics, the thermodynamics of solutions, superfluidity, superconductivity, and liquid crystals. He modified the solution theory to take into account Brownian Motion and the interaction of ions with solute molecules and each other. He proposed the fourth or zeroth law of thermodynamics: if two systems are in equilibrium with a third, they are in equilibrium with each other.