Paul Halpern in Medium:
The LIGO (Laser Interferometer Gravitational-Wave Observatory) project was proposed by physicist Rainer (Rai) Weiss of MIT, along with Kip Thorne, Ronald Drever, Rochus Vogt and other researchers at Caltech. Born in Berlin in 1932 to a politically active family, Weiss emigrated with them at a young age to the United States to escape the terrors of the Nazi regime. Weiss received his PhD at MIT, in the field of atomic physics under the supervision of Jerrold Zacharias.
Zacharias had dedicated himself to building high-precision timepieces based on the predictable rhythms of atoms, an extraordinarily important endeavor with broad implications for a variety of scientific fields. As Weiss related, even Einstein in his final years, while engrossed in the search for a unified field theory, expressed interest in the MIT project to develop such clocks. If such devices could be perfected, one of their possible applications would be precise measurement of the effects of gravitation on time. This would help provide further confirmation of general relativity. Zacharias proudly introduced his project to Weiss.
“Jerrold said to me,” recalled Weiss, “that he had made himself a clock called the ‘fountain clock,’ which was a brand new idea involving tossing atoms high into the air and timing them. The idea was to get a long observation time on the atom. He kept telling me that if we could get the clock running, I would travel to the Jungfraujoch, a scientific observatory high in the Swiss Alps. He would be with his clock in the valley and we would measure the Einstein redshift. That’s what set the bee in my bonnet about relativity. But the clock didn’t work; it was a total failure.”
Nevertheless, Weiss’s interest in experimental tests of general relativity only grew.