In 1998, observations of very distant exploding stars provided intriguing evidence that the expansion of the Universe is speeding up with time, rather than slowing down due to gravity as expected. Today, new and completely independent observations strongly support this amazing conclusion. Over the largest scales of space, our Universe seems to be dominated by a repulsive "dark energy," stretching the very fabric of space itself. Dr. Filippenko, who is a leader in the group that has made some of these remarkable observations, gives us a progress report on our "runaway universe" and then answers a host of audience questions about the overall behavior of the universe. Recorded October 4, 2006