Scientific Colloquium
April 2, 2004

Cosmology, the study of the structure of the universe as a whole, used
to be derided as a branch of metaphysics: full of speculation and
wonderful ideas, but few quantitative facts.  However, massive surveys
of the nearby and distant universe have allowed astronomers to
develop a coherent, self-consistent, and very well-tested model for
the universe in which we live.  I will discuss various parts of this
story, with particular emphasis on the Sloan Digital Sky Survey, which
has mapped the distribution of almost half a million galaxies, thereby
cementing our knowledge of the local universe.