Title: Supernova Searches, Dark Energy and the Causal Structure of the Universe


Supernova observations show that supernova at are dimmer than would be expected in an FRW universe with a decelerating expansion. This, and other data have led us to infer that the energy density of the universe is dominated by dark energy -- an energy source with negative pressure comparable in magnitude to its energy density -- and, perhaps most exciting, that is initiating a new epoch of cosmic inflation. In this talk I will discuss what it would take observationally to put some of these inferences on stronger footing and some of the eschatological implications if these inferences are confirmed. I will also discuss, briefly, a result relating to strategies for improving the statistical confidence level of these results.