Dark Energy and the Accelerating Universe: Einstein’s Blunder Undone

When: Tuesday, November 29, 2011 at 4:00 pm
Where: DA 114
Speaker: Professor Robert Kirshner
Organization: Harvard University
Sponsor: The 2011 Physics Nobel Prize Seminar

“Supernovae, exploding stars halfway across the universe, reveal an extraordinary fact: the expansion of the universe is speeding up. We attribute this to a dark energy that acts to make the universe spring apart. This discovery, published in 1998, led to the 2011 Nobel Prize in Physics being awarded to Saul Perlmutter at Lawrence Berkeley Lab, Brian Schmidt of the Australian National University, and Adam Riess of Johns Hopkins and the Space Telescope Science Institute. The resulting picture is a truly strange one: most of the universe is in the form of dark matter we cannot see and dark energy we do not yet understand. Only 4% of the mass-energy of the universe is in the form of atoms that can make stars, galaxies, planets, and people. This talk will show how we know the universe is accelerating and sketch how today’s idea of dark energy resembles Einstein’s cosmological constant.”

Robert Kirshner is Clowes Professor of Science at Harvard University and was thesis adviser for both Brian Schmidt and Adam Riess. A 1970 graduate of Harvard College, Kirshner received his Ph. D. from Caltech and recently received an honorary Doctor of Science degree from the University of Chicago. Kirshner won the AIP’s 2011 Heineman Prize in Astrophysics for “his sustained and enduring contributions to our understanding of supernovae and cosmology.” A frequent public lecturer on astronomy, he teaches a large undergraduate General Education course at Harvard called “The Energetic Universe” and is the author of popular-level book The Extravagant Universe: exploding stars, dark energy, and the accelerating cosmos.