In Baltimore, it was still dark in the early morning hours of October 4, 2011. In a modest home not far from the Homewood campus, Adam Riess, Hopkins’ Krieger‑Eisenhower Professor in Physics and Astronomy, and his wife Nancy, were being stirred from sleep by the babblings and cries of their 10‑month‑old son. Suddenly the phone rang. At first, Riess thought it was still the middle of the night. Then he glanced at the clock and saw it was 5:36 a.m. He knew that was about the time the call supposedly comes.

THE call.

Everybody knew it was the day the Nobel Prize in physics would be announced, but no one knew the details of that closely guarded secret. Until that pre‑dawn moment.

Riess answered the phone, and on the other end were several people saying they were from the Royal Swedish Academy of Sciences and that this was a very important call. Riess was told that he was one of three physics researchers to win what many consider the most prestigious award in the world—the Nobel Prize. He would share the prize with fellow scientists Saul Perlmutter, an astrophysicist at the University of California, Berkeley and the Lawrence Berkeley Laboratory, and Brian Schmidt, an American astronomer based at the Australian National University.

Riess, 41, along with Schmidt, was given the prize for leading a group of researchers known as the High‑z Team, to its 1998 unexpected discovery that the expansion of the universe is accelerating, and that acceleration is caused by the unexplained “dark energy” that comprises the majority of the universe. Riess led the study of difficult and precise measurements—across 5 billion light‑years—that resulted in the remarkable findings, which some say have changed the field of astrophysics forever.

Riess’ High‑z Team initially set out to use exploding stars called supernovas to measure how much the universe had expanded in the past and how much it was expanding now. He expected to discover that gravity had slowed the expansion of the universe. Much to his disbelief (he figured he must have made a mistake along the way), the research showed that the expansion of the universe had not slowed down at all. Rather, it was accelerating, and fast. And it’s that mysterious dark energy that’s acting as the “gas pedal.”

Albert Einstein was actually the one who first proposed the idea of a kind of “anti‑gravity” energy that could act repulsively, accelerating the expansion of the universe. At the time, however, Einstein thought it was the biggest blunder he’d ever made. “Maybe he [Einstein] should be getting the Nobel Prize again,” joked Riess in an early‑morning phone interview.

That would be the first of many interviews Riess would give that day to news organizations throughout the world. The barrage of phone calls began even before he left the house for Hopkins, as the news began to spread. Even as he was leaving his house, Riess was approached by a photographer from Reuters news service. Driving onto campus, he was met by a small crowd of journalists and well‑wishers. At his office in the Bloomberg Center for Physics and Astronomy, department chair Daniel Reich was waiting with champagne.

Riess isn’t the only Nobel Prize recipient in the physics and astronomy department. In 2002, astrophysicist Riccardo Giacconi received a Nobel for his groundbreaking work inventing the field of X‑ray astronomy.

Speaking at a midday press conference were President Ronald J. Daniels; School of Arts and Sciences Dean Katherine S. Newman; and Matt Mountain, director of the Space Telescope Science Institute, where Riess is also a member of the senior scientific staff. The audience included Carol Greider, professor and director of Molecular Biology and Genetics in the School of Medicine and recipient of the 2009 Nobel Prize in medicine. Riess is the 35th person associated with Johns Hopkins as a faculty member, fellow, or graduate to win a Nobel Prize.

Most of the Hopkins community already knew they were in the midst of a Nobel Prize winner, thanks to a broadcast email President Daniels had sent in the morning to all faculty, staff, and students. In that email, Daniels lauded Riess for his pursuit of discovery, saying, “Dr. Riess has a passion to know more. The energy with which he pursues that passion exemplifies the commitment made by all of us across Johns Hopkins to deploy knowledge to create a better and more humane world. We are honored by his association with our university.”

As Nobel Prize recipients, Riess, Perlmutter, and Schmidt will share a cash award of $1.49 million, and each will receive a medal and diploma in Stockholm in December.

“We at the Krieger School of Arts and Sciences are enormously proud of this most significant accomplishment,” said Newman. “This type of internationally recognized achievement illustrates all that Johns Hopkins is about: the quest for knowledge, the drive for discovery, and the passion to make a difference in the world. Adam’s exceptional efforts in unlocking some of the mysteries of our vast universe are awe inspiring, and he is most deserving of this award.”

So what’s next for Nobel Prize winner Adam Riess? He wants to keep doing what he’s been doing. “This is a great place to do science,” he said of Hopkins.

“One of the most exciting things about dark energy is that it seems to live at the very nexus of two of our most successful theories of physics: quantum mechanics, which explains the physics of the small, and Einstein’s general theory of relativity, which explains the physics of the large, including gravity,” said Riess. “Nature somehow must know how to bring these both together, and it is giving us some important clues. It’s up to us to figure out what they’re saying.”