On Thursday, April 18, students, faculty, visiting families, and Middletown residents gathered in the Center for the Arts Hall to attend the Sturm Memorial Lecture, an annual event that brings a renowned astronomer to campus to give an accessible, public lecture on his or her field of expertise. This year’s speaker was Nobel Laureate Adam Riess.
The lecture is given every year in honor of the late Kenneth E. Sturm ’40, who loved astronomy but did not pursue it as a career. Upon his death, his sister, Ruth Sturm, donated money to the University for a scholarship in his honor; as a thank-you, the Astronomy Department instituted the annual lecture.
John Monroe Van Vleck Professor of Astronomy and Chair of the Department William Herbst explained that the lecture celebrates the fact that one can be passionate about the sciences without being a scientist oneself.
“The point of the lecture series was to make it not a lecture for professional astronomers or the faculty but a lecture that everybody could enjoy,” Herbst said. “That’s the nature of the Sturm lecture. It’s a public lecture, and we always get a leading astronomer who is also good at communicating his thoughts to the general public.”
The lecture, first held in 1991, has seen its share of impressive speakers. Notable lecturers from the past include John Mather, another Nobel Laureate, and Taft Armandroff ’82, a Wesleyan alumnus and director of the world’s largest observatory.
Herbst spoke about the decision process behind choosing each year’s speaker.
“The department gets together, and we trade ideas about who we think would be an excellent person to come,” Herbst said. “This year’s speaker is a Nobel Laureate, so that put him well up on the list. He’s also well known to us, so that helped. We also know that he’s a younger astronomer and a dynamic speaker who’s good at communicating. He fit the bill.”
Fit the bill is right. Riess, the Thomas J. Barber Professor of Physics and Astronomy at Johns Hopkins University, is the recipient of many honors, including the Robert J. Trumpler Award for an Outstanding Ph.D. Thesis in Astronomy, the Helen B. Warner Prize for Astronomy, and the Einstein Medal, not to mention his 2011 Nobel Prize in physics, awarded for his team’s proof of the universe’s accelerating expansion.
Associate Professor of Astronomy Edward Moran introduced Riess, with whom he worked on a research team at the University of California, Berkeley.
“As a scientist, he’s very inspiring to me and to many others,” Moran said. “He focuses on just the most important problems and puts his emphasis on finding the most creative solutions to these problems. He’s not about writing a zillion articles that have minimal impact in the field just because he can—he takes his time, and he makes sure that everything he does matters.”
Riess’ lecture focused on the expansion of the universe, which, as his research team confirmed in their paper “Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant,” is evidence for the force known as dark energy.
“You can think of the expanding universe as a loaf of raisin bread rising in the oven,” Riess explained. “The galaxies are kind of like the raisins, and as the loaf rises, the raisins, which are far apart to begin with, rush apart even faster. It doesn’t matter where you sit in this loaf: the same phenomenon exists, where everything looks like it’s moving away from everything else.”
In confirming the accelerating expansion of the universe and the existence of dark energy, Riess and his team were effectively proving the existence of what Einstein had dubbed the “cosmological constant,” now known as dark energy. With only 5 percent of the universe comprised of planets, stars, and gas and the remaining 95 percent comprised of dark matter and dark energy, the latter is of unquestionable significance to astronomers’ understanding of the universe.
Yet what, exactly, is the deeper explanation behind dark energy? That is something that astronomers are only now beginning to explore. Riess showed a clip from the show “The Big Bang Theory” in which Sheldon, a theoretical physicist, scoffs at the Nobel Prize acceptance ceremony in Stockholm—the same event at which Reiss was awarded for his research.
“Look at these men,” the character says. “They’ve managed to win the top science prize in the world with no more understanding of the quantum underpinnings of the expansion of the early universe than God gave a goose.”
As Riess admitted, Sheldon isn’t terribly far off in his accusation.
“I would say, guilty as charged,” Riess said. “We have observed that the universe is accelerating, and we have attributed it to dark energy, but we don’t really have a good, deep understanding of the ‘quantum underpinnings’ of the source of this dark energy.”
That, of course, is the next step. Riess concluded his lecture by underlining the importance of ultimately coming to a true understanding of dark energy, now that there is substantial evidence for its existence.
“It’s hard to say that we really understand the universe if we can’t understand the biggest part of it, and we believe it will determine the ultimate fate of the universe,” Riess said. “We have to understand the nature of dark energy, whether it’s changing or not, to make predictions about the future.”