Barry Barish, 81, a Caltech particle physicist, later guided the construction of the twin LIGO observatories in Hanford, Washington, and Livingston, Louisiana. Each of LIGO’s L-shaped interferometers acts like a pair of perpendicular rulers. LIGO’s interferometers can detect a difference in length as small as 1/10,000 the width of a proton.
“LIGO wouldn’t have happened without his leadership,” says Stanley Whitcomb, a physicist at Caltech and an original member of LIGO. “It was something that Rai[ner] and Kip couldn’t do.”
Drever invented several key elements of the LIGO design, Whitcomb says, but he was not as self-effacing as Weiss and Thorne.
Last month, researchers announced the discovery of a fourth black-hole merger that had been spotted not only by the LIGO detectors, but also by Europe’s premiere detector-the freshly upgraded Virgo detector near Pisa, Italy-which enabled scientists to better pinpoint the merger’s location on the sky.
The one thing LIGO has yet to deliver is a surprise, Weiss notes.