WASHINGTON — A Johns Hopkins University professor was one of three scientists awarded the 2011 Nobel Prize in physics 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 the university, won the prize with fellow American Saul Perlmutter and U.S.-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

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.

The work Riess is being honored 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.