- Person
- Saul Perlmutter
- Lived
- b. 1959
- Field
- Astrophysics
- From
- American
The story
Saul Perlmutter was born in 1959 and grew up in Philadelphia, the son of two professors; all four of his grandparents were Jewish immigrants from Eastern Europe, and his maternal grandfather taught Yiddish literature and history. As a Berkeley graduate student he wrote software for a robotic telescope that automatically searched for supernovae, exploding stars.
One kind of supernova, called Type Ia, explodes with nearly the same brightness every time, so comparing how bright one appears with how bright it really is reveals its distance. Astronomers had long hoped such explosions could measure how much the expansion of the universe was slowing under gravity. In 1987 Perlmutter and Carl Pennypacker proposed searching thousands of distant galaxies at once with a new wide-field digital camera, and in 1988 the Supernova Cosmology Project began at Lawrence Berkeley National Laboratory.
The early years were frustrating, with bad weather and few discoveries. By 1994 the team had learned to guarantee batches of newly exploding distant supernovae on chosen dates, so that time could be booked in advance on the world's largest telescopes, including the Hubble Space Telescope. In 1997, analysing 42 distant supernovae, they found the opposite of what they expected: the supernovae were farther away than a slowing universe would allow. The expansion was speeding up. They announced the evidence in January 1998, and a rival team led by Brian Schmidt, with Adam Riess, reported matching results at almost the same time.
The finding implies that some unknown dark energy, thought to make up about three quarters of the universe, drives space apart. In 2011 Perlmutter received half of the Nobel Prize in Physics and Schmidt and Riess shared the other half. Perlmutter said it was the kind of discovery the whole world could feel part of, as humanity advances its knowledge of the universe.
Why it matters
The discovery of dark energy reshaped our understanding of the cosmos and launched a worldwide effort, with new telescopes and satellites, to learn what most of the universe is made of.
About Saul Perlmutter
Berkeley astrophysicist whose team found the universe’s expansion is speeding up, revealing dark energy, and who now teaches the public how to think like scientists. Nobel Prize 2011.
More about Saul Perlmutter
Sources
- Saul Perlmutter, Biographical NobelPrize.org
- Press release: The Nobel Prize in Physics 2011 NobelPrize.org
- Berkeley Lab's Saul Perlmutter Wins 2011 Nobel Prize in Physics Lawrence Berkeley National Laboratory
Another act of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.