An invited review presented at Stellar Collisions, Mergers, and
New York, New York, USA, 30 May - 2 June, 2000.
I compare gas-dynamical and stellar-dynamical models of collisions. These two models have distinctly different physics; for example, shocks introduce irreversibility in gas systems, while stellar systems evolve in a completely reversible fashion. Nonetheless, both models yield broadly similar results, suggesting that analogies between gas and stellar dynamics have some heuristic validity even applied to collisions.
A gzipped postscript copy of this paper is available. The text will appear in Stellar Collisions, Mergers, and Their Consequences, ed. M. Shara (Astronomical Society of the Pacific). This paper is also available as astro-ph/0010145.
Last modified: October 6, 2000