Speaker: Prof. Alex Filippenko (University of California, Berkeley)

 Date: May 8, 2015 (Friday)

Time: 2:00pm

Venue: Sunshine Hall, Yingjie Overseas Exchange Center

Contacts: Hu Yongyun 
          Tel: 62754291 
     E-mail: yyhu@pku.edu.cn

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, an amazing discovery that was honored with the 2011 Nobel Prize in Physics to the teams’ leaders and the 2015 Breakthrough Prize in Fundamental Physics to all team members. Over the largest distances, the Universe seems to be dominated by a mysterious, repulsive “dark energy” – an idea Albert Einstein had suggested in 1917 but abandoned in 1929 as his “biggest blunder.” It stretches space itself faster and faster with time. But the physical origin and nature of dark energy, which makes up about 70% of the contents of the Universe, is probably the most important unsolved problem in all of physics; it may provide clues to a unified quantum theory of gravity.

Introduction of the speaker:
Alex Filippenko, an elected member of the US National Academy of Sciences, is one of the world's most highly cited astronomers. He is the recipient of numerous prizes for his scientific research, and was the only person to have been a member of both teams that revealed the accelerating expansion of the Universe. This discovery was honored with the 2011 Nobel Prize in Physics to the teams’ leaders and the 2015 Breakthrough Prize in Fundamental Physics to all team members. 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. He has produced 5 astronomy video courses with The Great Courses, coauthored an award-winning astronomy textbook, and appears in more than 100 television documentaries. In 2004, he was awarded the Carl Sagan Prize for Science Popularization.

Edited by: Choisum Kwok

Source: Office of International Relations, School of Physics, PKU / Alumni Secretariat, School of Physics, PKU