Citation | Scott D Tremaine is distinguished for his work on planetary rings and dsks, and in theoretical astrophysics. The kinetic theory of rings and particles in both dilute and dense limits is due to him and his collaborators and he has studied numerically the intermediate case. With Goldreich he predicted density waves in Saturn's rings and shepherd satellites of thin rings since observed by spacecraft in the ring systems of Saturn and Uranus. He demonstrated that tides, not panning stars, are the primary creators of 'new' comets and in consequence modified our concept of the extent of Oort's proto-cometary cloud. With Binney he has written an outstanding book on Galactic Dynamics, a field to which he has made vital contributions; His considerations of phase-space put severe constraints on the idea that neutrinos with rest mass are a major constituent of the universe. He has derived new tests of the equivalence principle for both neutrinos and photons. Tremaine is the founding Director of the outstandingly successful Canadian Institute for Theoretical Astrophysics to which he has drawn a most able staff. |