Title: Shedding Light on the Dark Universe

Abstract:
Discoveries in the last few years have revolutionized
our knowledge of the universe and our ideas of its ultimate fate.
Measurements of the expansion of the universe show that it is not
slowing down under normal gravity but accelerating due to an unknown,
gravitationally repulsive "dark energy". This may be a clue to new
properties of quantum physics or of gravity "beyond Einstein".
I present an overview of the puzzles of dark energy and the means
for unraveling them through cosmological probes. Next generation
experiments such as the Supernova/Acceleration Probe (SNAP) satellite
would measure the supernova distance-redshift relation to high accuracy
and map the evolution of structure and dark matter through gravitational
lensing. These observations will explore the frontiers of physics and
aim to uncover what makes up the still unknown 95% of our universe,
while producing astronomical images equal to a million Hubble Deep 
Fields.