THREE US-BASED scientists have been awarded the 2011 Nobel Prize in physics today for discovering that the universe is expanding at a faster and faster rate, contrary to science’s conventional wisdom.

The Royal Swedish Academy of Sciences announced that Adam Riess, an astronomy and physics professor at Johns Hopkins University, won the prize with fellow American Saul Perlmutter and US-Australian citizen Brian Schmidt.

Perlmutter heads the Supernova Cosmology Project at the University of California, Berkeley. Schmidt is the head of the High-z Supernova Search Team at the Australian National University in Weston Creek, Australia.

Race

Working in two separate research teams during the 1990s — Perlmutter in one and Schmidt and Riess in the other — the scientists raced to map the universe’s expansion by using telescopes to study and analyze a particular type of supernovas, or exploding stars. They were surprised to find that far-away galaxies were racing away from each other at an ever-increasing speed.

Riess, 41, said he got a phone call around 5:30 a.m. Several Swedish men were on the line, at which point “I knew it wasn’t Ikea”.

“My jaw dropped. I couldn’t believe it. I didn’t know if this would happen ever,” he said in a telephone interview.

The work Riess is being honoured for stems from a 1998 discovery that the rate at which the universe is expanding is speeding up, a discovery Riess called “truly startling.”

The discovery contradicted conventional scientific wisdom that the universe’s expansion would be slowing down as a result of what Riess calls the “gravitational glue” of the rest of the universe. The work led to the discovery of what’s called dark energy, which is believed to be responsible for the universe’s accelerating expansion, though researchers still don’t know much about it.

Riess, who has an undergraduate degree in physics MIT and a doctorate in astrophysics from Harvard, said he spends the last two classes of his introductory astronomy course at Johns Hopkins talking about the discovery. He tells students in his “Stars and the Universe” class that they are fortunate to have such an “exciting mystery” to help solve.

“I sort of turn to them at that point and say, ‘I hope many of you continue on in this field and help us understand this mystery,’” he said.

Riess said that as a child he loved science and wanted to study dinosaurs. He didn’t use a telescope until graduate school, he said. He says he finds looking through a telescope awe inspiring.

“Most of it’s a mystery,” he said of looking out at the universe. “If we very carefully study this ancient tired light we can get some clues as to what really is the universe.”

A professor at Johns Hopkins University last won a Nobel Prize two years ago. Carol Greider shared the 2009 prize in medicine for her work helping solving the mystery of how chromosomes protect themselves from degrading when cells divide.