A Brief History of Cosmic Expansion and Acceleration

Adam Riess
Astrophysicist, Johns Hopkins University

2261st Meeting Abstract
Friday, December 4, 2009 at 8:15 PM

Adam Riess


In 1929 Edwin Hubble discovered that our Universe is expanding. Eighty years later, the Space Telescope which bears his name is being used to study an even more surprising phenomenon, that the expansion is quickening. The origin of this effect is not known, but is broadly attributed to a type of “dark energy” first posited to exist by Albert Einstein and now dominating the mass-energy budget of the Universe. The author will describe how his team first discovered the acceleration of the Universe and why understanding the nature of dark energy presents one of the greatest remaining challenges in astrophysics and cosmology.

About the Author:

Adam Guy Riess is an astrophysicist at Johns Hopkins University. He leads the Higher-Z SN Search program, which uses the Hubble Space Telescope to discover distant supernovae. This program has studied the expansion of the universe over 10 billion years ago. This work has detected an early phase of decelerating expansion, causing the most distant supernovae to look relatively brighter. This tends to confirm the dark energy – dark matter model.

Before coming to Johns Hopkins in 2005, he had been at the Space Telescope Science Institute. Earlier, he was a Miller Fellow at the University of California at Berkeley. In 1998, he led the study for the High-Z Supernova Search Team which first reported evidence that the universe's expansion rate is accelerating. This result was also found by the Supernova Cosmology Project. Science Magazine named the discovery of the accelerating universe the 1998 “Breakthrough of the Year.”

In 1999, Adam Riess received the Trumpler Award from the Astronomical Society of the Pacific. He received the Bok Prize from Harvard University in 2001. The American Astronomical Society awarded him the Helen B. Warner Prize in 2003 and the Raymond and Beverly Sackler Prize in 2004. In 2006, the American Astronomical Society awarded the $1 million Shaw Prize in Astronomy for the discovery of cosmic acceleration, in which he shared. He and the other members of the High-Z team and the Supernova Cosmology Project also shared the $500,000 Gruber Cosmology Prize in 2007. Adam Riess was awarded a Macarthur “Genius” Grant in 2008. He is a member of the National Academy of Sciences.

He received his bachelor's degree from MIT in 1992 and his Ph.D. from Harvard in 1996.

←Previous Abstract - Directory of Archived Meetings - Next Abstract→