Dark Energy and the Runaway Universe Lecture 13 Dark Energy and the Runaway Universe Prof. Alex Filippenko University of California, Berkeley 时间: 2015年5月8日（周五） 下午2点 地点：北京大学英杰交流中心 阳光厅 Abstract We expected the attractive force of gravity to slow down the rate at which the Universe is expanding. But observations of very distant exploding stars (supernovae) show that the expansion rate is actually speeding up. Over the largest distances, the Universe seems to be dominated by a mysterious, repulsive “dark energy.” It stretches space itself faster and faster with time. But the physical origin and nature of dark energy is probably the most important unsolved problem in all of physics; it may provide clues to a unified quantum theory of gravity. Alex Filippenko, an elected member of the US National Academy of Sciences, is one of the world's most highly cited astronomers. Winner of the most prestigious teaching awards at UC Berkeley and voted the “Best Professor” on campus a record 9 times, he was named the National Professor of the Year in 2006. In 2004, he was awarded the Carl Sagan Prize for Science Popularization. 北京大学物理学院 School of Physics, Peking University Contact: 胡永云 (Yongyun Hu), Tel: 62754291, email: yyhu@pku.edu.cn