Scientific Colloquium
April 1, 2005


How and when did the cosmic dark ages end? I present simulations of the
formation of the first stars and quasars, discuss their impact on the
intergalactic medium, and describe ways to probe their signature with
the WMAP and JWST missions. The first supernovae are responsible for the
initial metal enrichment of the cosmic gas. This initial enrichment event
is predicted to fundamentally change the character of star formation in
the universe, from a high-mass dominated mode at early times to a low-mass
dominated one more recently. Finally, I describe the properties and
statistics of high redshift Gamma-ray Bursts. The Swift satellite is
ideally suited to test these ideas.