After the Big Bang around 13.8 billion years ago, the universe was so hot that light couldn’t shine. As the cosmos expanded, temperatures dropped. Eventually, around 380,000 years following the Big Bang, the oldest known light in the universe appears. Called the cosmic microwave background, this afterglow provides scientists with a glimpse of what happened during the early cosmos.

In this lecture, Lyman Page will discuss the way that cosmologists think about the universe on its grandest scales by painting a physically intuitive picture. In this context, he’ll pay particular attention to how one should think about the cosmic microwave background and its implications for cosmology. He’ll also discuss what current earth-based measurements could tell us about the cosmic microwave background.

Page is the James S. McDonnell Distinguished University Professor of Physics at Princeton University. He received his B.A. from Bowdoin College in 1978 and, following a five-year break, his Ph.D. from MIT in 1989. During the intervening years, he was a research technician in Antarctica and rebuilt and sailed a 37-foot wooden ketch along the East Coast and in the Caribbean. He was a founding member of the WMAP satellite project and the founding director of the Atacama Cosmology Telescope (ACT) project. He currently works on the Simons Observatory as well as ACT. He has received awards for his research and is a member of the National Academy of Sciences.