| Citation | Distinguished for his important and wide-ranging studies of quantum fluids and solids, enhanced by the elegant application of thermodynamics. After early work at Oxford on heat conduction in superfluid 4He, his work has been mainly with the school, founded by Daunt, that he built up at Ohio State University. He made the first observations of the melting curve of 3He-4HE mixtures, and of the finite solubility of 3He in liquid 4He as T -> O, followed by a definitive study of the thermodynamic and transport properties of dilute 3He-4HE solutions. He pioneered the study of the liquid 4He surface, particularly the effect of small amounts of 3He, and has also done innovative work on the liquid-solid interface and the roughening transition. Recent work at millkelvin temperatures has led to the observation of collisionless spin waves in normal and superfluid 3He. |