Johns Hopkins astrophysicist Adam Riess and two
colleagues last week were awarded this year's $1 million
Shaw Prize in astronomy for their discovery that an
unexplained mysterious "dark energy" is driving an
ever-faster expansion of the universe.
Riess, 36, who is also an astronomer at the
Space Telescope Science
Institute, said he learned of the award in an e-mail
message from a journalist in Hong Kong asking for an
interview. Later, a colleague called his home from
campus.
"He said, 'There's a thing on the fax machine'" from
the Hong Kong-based Shaw Prize Foundation saying he had won
a share of $1 million, Riess said. "I'm like, 'OK, hang
onto that.'"
This is the third year for the Shaw Prize, awarded
annually in three fields: astronomy, life science and
medicine, and mathematical sciences. The prize was
established by Run Run Shaw, a philanthropist and longtime
leader in the Hong Kong film and television business. This
year's presentation ceremony will be held Sept. 12.
Co-winners of the 2006 astronomy prize with Riess are
Saul Perlmutter of the Lawrence Berkeley Laboratory of the
University of California, Berkeley, and Brian Schmidt of
the Mount Stromlo Observatory of the Australian National
University in Canberra.
Riess and Schmidt were leaders of one team that
pursued highly difficult and challenging measurements that
led to the dark energy discovery in 1998; Perlmutter was
the leader of a competing team.
"We set out to measure the expansion rate of the
universe in the past and compare it to the expansion rate
of the present universe, using exploding stars called
supernovae," Riess said. They expected to find that gravity
— the force by which everything in the universe tugs
at everything else and tends to attract it all together
— had slowed the rate of expansion over time.
"So it was startling to find that the expansion rate
was speeding up," Riess said.
That, he said, sent astronomers back to an idea
developed but eventually discarded by Albert Einstein as
"my biggest blunder." That idea, Riess said, implied that
there might be a sort of "anti-gravity" — that "the
vacuum of space had energy in it and that energy could act
repulsively and accelerate the expansion of the
universe.
"Today, we call this phenomenon 'dark energy,'" he
said. Though it may account for 70 percent of the universe,
"we still don't understand it very well," he said.
A 2003 National Academy of Sciences report referred to
the nature of dark energy as "the deepest mystery in
physics" and said "its resolution is likely to greatly
advance our understanding of matter, space and time."
Riess said he, his colleagues and many other
astronomers are working to learn more, using the Hubble
Space Telescope and ground-based experiments. In 2003, for
example, Riess announced results from Hubble observations
of Type 1a supernovae. The new results indicated that a
"cosmic jerk" occurred 5 billion years ago, a transition
from a state in which gravity was predominant, putting the
brakes to universal expansion, to a state in which dark
energy took over and began accelerating the expansion.
Riess and others are working with NASA and the
Department of Energy to explore the possibility of a Joint
Dark Energy Mission, a satellite with an array of
instruments that would be dedicated to exploring dark
energy.
Riess, previously an adjunct associate professor,
joined the Johns Hopkins
Physics and Astronomy faculty full time in January. He
has been an astronomer since 1999 with STScI, the science
headquarters of the Hubble Space Telescope. From 1996 to
1999, he was a Miller Fellow at the University of
California, Berkeley.
Riess is a 1992 graduate of MIT, with a major in
physics and a minor in history. He earned his doctorate in
astrophysics from Harvard in 1996.