Lab Rat of the Week: Kirshner Aims For Stars

A snow blower, some drywall, and a trip to Cuba.

This is how Astronomy Professor Robert P. Kirshner ’70, recipient of the 2015 Wolf Prize, has decided to spend his prize money. The snow blower for obvious reasons, drywall to fix up the third floor of his house in Maine, and the trip to Cuba as part tropical break from Cambridge, part homage to Ricardo Wolf, the namesake of the award that Kirshner received at the end of January.

The Wolf Prize, according to its website, is awarded to those responsible for “achievements in the interest of mankind and friendly relations among people.” Kirshner won this accolade for his work using supernovae to measure distances between stars, proving that the universe is growing at an increasing rate, not a decreasing one, as had previously been thought.

Since the 1930s, it has been established that the universe is expanding. Most took for granted that, as time progressed, the expansion of the universe would slow down as the forces of gravity pulled bodies toward each other. As a member of the High-Z Supernova Search Team, Kirshner set out to discover the universe’s expansion rate. To this end, his team investigated supernovae, the thermonuclear explosions of collapsing stars. Kirshner used the differing brightness of supernovae to determine the distance between galaxies, based on the principle that the closer a star is, the brighter it will appear.

After making their measurements, Kirshner’s team found that rather than decelerating, the universe’s growth was, in fact, accelerating. The discovery was named Science magazine’s 1998 “Breakthrough of the Year” and has ultimately led to the study of dark matter, the energy presumed to be counteracting gravity to push the universe to expand at an ever-increasing rate.

The 2011 Nobel Prize in Physics was awarded to Kirshner’s graduate students Adam G. Riess and Brian P. Schmidt as well as Saul Perlmutter ’81, a physicist from the University of California, Berkeley who led a parallel team investigating the expansion of the universe. The Nobel Prize has a stipulation that the prize can be awarded to three people at the most. This year’s Wolf Prize celebrates Kirshner’s contributions to the High-Z Supernova Search Team and the field of supernova cosmology, both in an advising and research capacity.

For years, Kirshner has taught broader audiences about his findings through general education classes on these topics, including “The Energetic Universe” this semester.

“I think the fact that  instruction is as good as it is in the College depends on the fact that people who are really good at what they do really care about it and want to tell people about it,” Kirshner said.

A prop from the television series "Gilmore Girls" sits atop the bookshelf of Robert Kirschner, whose daughter was a writer on the show. By Courtesy of Ramsey Fahs

Kirshner’s discoveries have even permeated popular culture.  Kirshner’s daughter, a former writer for the hit TV show Gilmore Girls, wrote him into the show on the sly during an episode set at Yale parents weekend. In the episode, the characters decide to attend a lecture on the accelerating universe by Professor Quincy, in reference to Quincy House, where Kirshner lived as an undergraduate and served as housemaster from 2001-2007.

“I was even going to act [in the show] but we couldn’t get the screen actor’s guild to sign off fast enough,” said Kirshner.

—Staff writer C. Ramsey Fahs can be reached at cfahs@college.harvard.edu. Follow him on Twitter @ramseyfahs.