Recent results from the CERES experiment at the SPS are reviewed. Emphasis is
put on the centrality and beam energy dependence, and the results are put into
perspective with findings at lower and higher beam energies. The rather weak
beam energy dependence of the HBT radii maybe understood in terms of a
transition from baryon to pion dominated freeze-out. The observed short
lifetimes end emission durations are presently in contradiction to results from
model calculations.Comment: Invited talk at the International Workshop XXX on Gross Properties of
Nuclei and Nuclear Excitations - Ultrarelativistic Heavy-Ion Collisions, Jan.
13-19, 2002, Hirschegg, Austria. 11 pages, 8 figure