- Person
- Rainer Weiss
- Lived
- 1932–2025
- Field
- Experimental physics
- From
- German-American
The story
Rainer Weiss was born in Berlin in 1932 to a Jewish father, a neurologist who was forced out by the Nazis, and a Protestant mother. The family fled to Prague and, after the Munich Agreement of 1938, to the United States, helped by the Stix family of St. Louis, who guaranteed entry for Jewish refugees. Weiss grew up in New York, studied at the Massachusetts Institute of Technology and joined its faculty in 1964.
Einstein's general theory of relativity predicted that moving masses produce gravitational waves, ripples in space-time itself, but they were expected to be so faint that Einstein thought they could never be measured. In 1966 Weiss was teaching a course on general relativity. When students asked about another physicist's claims to have detected the waves, he could not make sense of the claims, so he worked out the simplest possible way to show how a gravitational wave might be detected: measure the time light takes to travel between floating masses.
He then replaced the impossibly precise clocks with a laser interferometer. A laser beam is split down two long arms at right angles, bounced off mirrors and recombined. A passing gravitational wave stretches one arm while squeezing the other, changing how the two beams combine. In a 1972 report Weiss analysed every source of noise that could drown such a tiny signal and concluded that an instrument with arms kilometres long could succeed. The Nobel committee noted that he had both designed the detector and analysed its noise sources by the mid-1970s.
With Kip Thorne and Ronald Drever, Weiss co-founded the Laser Interferometer Gravitational-Wave Observatory, LIGO, built in Washington state and Louisiana with funding from the National Science Foundation. On September 14, 2015, both detectors recorded waves from two black holes that had collided about 1.3 billion years ago, a change in arm length thousands of times smaller than an atomic nucleus. Weiss shared the 2017 Nobel Prize in Physics.
Why it matters
LIGO and its partner observatories now detect collisions of black holes and neutron stars, giving humanity an entirely new way to observe the universe.
About Rainer Weiss
Refugee from Nazi Germany who conceived the laser detector behind LIGO, which first caught gravitational waves in 2015 and opened a new way to observe the universe. Nobel Prize 2017.
Sources
- Press release: The Nobel Prize in Physics 2017 NobelPrize.org
- Rainer Weiss, Biographical NobelPrize.org
- Professor Emeritus Rainer Weiss, influential physicist who forged new paths to understanding the universe, dies at 92 MIT News
- Rainer Weiss Wikipedia
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.