Rainer Weiss, who shared a Nobel Prize in Physics for developing a device that uses gravity to detect intergalactic events, like black holes colliding, and who helped confirm two central hypotheses about the universe: the Big Bang theory of how and when it began and Einstein's theory of general relativity, died on Monday in Cambridge, Mass. He was 92.
His death, in a hospital, was confirmed by David Reitze, the executive director of the Laser Interferometer Gravitational-Wave Observatory, or LIGO, a bicoastal project operated jointly by the California Institute of Technology in Pasadena and the Massachusetts Institute of Technology in Cambridge.
Dr. Weiss, along with the physicists Barry C. Barish and Kip S. Thorne, received the 2017 Nobel in physics for their work building LIGO, a large-scale instrument that two years earlier detected an intergalactic "chirp" of gravitational waves, created by the collision and merging of two black holes about 1.3 billion years ago.
The discovery shook the scientific community and confirmed Einstein's general theory of relativity -- that space and time can be stretched, compressed and pulled by the acceleration of massive objects.
"We now witness the dawn of a new field: gravitational wave astronomy," Nils Martensson, a physics professor and the acting chairman of the Nobel physics selection committee, said when the prize was announced. (Dr. Weiss, who worked out of LIGO's lab at M.I.T., was awarded one-half the prize; Drs. Thorne and Barish, who were at Caltech, each received one-quarter.)
Dr. Weiss, a German-born American, was teaching a course in general relativity at M.I.T. in the late 1960s when he first sketched out the idea that would become the LIGO project.
Years earlier, the physicist Joseph Weber said he had found a way to detect gravitational waves, measuring how they compressed and elongated along the lengths of large aluminum cylinders. But no one could replicate the experiments.
After a failed first attempt to develop a new design, Dr. Weiss came up with one that he thought might work. Knowing that the waves should stretch and squeeze space as they traveled through it, he envisioned a device that would measure those disruptions. It would emit a laser beam that would be split in two, and then be recombined. Measuring the change in the interference pattern of the merging beams would make it possible to detect the waves.
Though the project idea was sound, its feasibility encountered a great deal of resistance. Speaking when the Nobel Prize was announced, Dr. Weiss recalled that when he explained the experiment to potential funders at the National Science Foundation, "everybody thought we were out of our minds."
Still, Dr. Weiss secured enough funding from M.I.T. to build a small-scale prototype in 1972. Dr. Thorne, a theorist who was initially skeptical that the detector could be built, became an enthusiastic supporter of the project and persuaded Caltech to recruit Ron Drever, a Scottish experimental physicist whom colleagues described as "a genius tinkerer," to help design and lead the detector.
Dr. Drever developed a way to fine-tune lasers by bouncing them off mirrors, which became essential in making it possible for LIGO to detect gravitational waves at different frequencies. He left the project in 1992 and died in 2017 before the Nobel Prize was announced. (The award is not given posthumously.)
Over the decades, the project grew, and eventually the National Science Foundation came on board. It insisted that Dr. Barish be appointed lead investigator. The NSF spent more than $1 billion developing LIGO, with other agencies and universities also contributing research and funding.
Still, he secured enough funding from M.I.T. to build a small-scale prototype in 1972. Over the decades, the project grew, and eventually the National Science Foundation came on board, spending more than $1 billion on the development of LIGO, with other agencies and universities also contributing research and funding.
The two detectors -- one in Hanford, Wash., and the other in Livingston, La. -- are nearly 1,900 miles apart and are often referred to as telescopes, each with two 2.5-mile-long tunnels sitting at right angles to each other. A laser beam is split and sent down each tunnel. At the end, the beams bounce off mirrors, return to the origin, are recombined and then enter a detector.
The experiment now includes a third detector, called Virgo, which is near Pisa, Italy. Altogether, about 1,500 scientists from about 100 institutions in 18 countries work on the LIGO and Virgo projects. To date, about 100 observations of intergalactic events have been made.
Around the time that he was beginning to conceive LIGO, Dr. Weiss became involved in another important project, one that solidified the Big Bang theory as the origin story of the universe.
In 1965, two scientists, Robert Woodrow Wilson and Arno Penzias, accidentally discovered the existence of cosmic microwave background radiation, thought to be evidence of the gigantic explosion of the Big Bang. But precise measurements of the radiation's temperature and thermal spectrum were still needed in order to confirm that theory.
Working with Dirk Muehlner, a graduate student, Dr. Weiss designed sensors that could be used on high-altitude balloons to take the measurements. After overseeing 20 balloon flights from 1967 to 1982, they established the temperature of the background radiation to be 2.73 degrees kelvin above absolute zero (about 455 degrees below zero Fahrenheit) and showed that its thermal spectrum was consistent with it being the remnant of the Big Bang.
Dr. Weiss subsequently became the co-founder and chair of a working group of scientists behind the Cosmic Background Explorer satellite, or COBE, which was launched by NASA and operated from 1989 to 1993. The satellite made a detailed study of the cosmic background radiation, further advancing knowledge of the origins of the universe.
In 2006, John C. Mather and George F. Smoot, two scientists who were part of the COBE project, received the Nobel Prize in Physics for their work. Some thought that Dr. Weiss should have shared in that prize. "It was a near miss," Peter Saulson, a physics professor at Syracuse University, told Science magazine in 2016.
Rainer Weiss was born in Berlin on Sept. 29, 1932. His father, Frederick, was a neurologist and an ardent communist. His mother, Gertrude Loesner, was an actress.
Just before Rainer was born, his father, who was Jewish, was abducted by the Nazis. His mother, a Protestant, used her political connections to get Frederick released and sent to Prague. After Rainer was born, she joined her husband there.
In 1938, a year after Rainer's sister, Sybille, was born, the Munich Agreement was struck, allowing Germany to annex the Sudetenland, a German-speaking border region of Czechoslovakia, and effectively opening the country to Nazi occupation. The family fled, securing visas to emigrate to the United States, helped by a St. Louis family that had managed to shepherd about 10,000 Jews into the country, as Dr. Weiss recalled in a Nobel biographical sketch.
They arrived in New York City in January 1939. Frederick Weiss eventually became a licensed psychoanalyst.
Rainer attended public schools in the city until fifth grade, when he switched to Columbia Grammar, a private school in Manhattan. When he was about 13, shortly after World War II ended, he began going to Cortlandt Street in Lower Manhattan to buy military surplus electronic components, using them to build radios and audio amplifiers. He soon had the skills to pick up business fixing radios and broken electronics.
"I learned most of the things in my life by building something and then trying to make it work," Dr. Weiss said in an interview with the Nobel Institute.
After graduating from high school in 1950, he entered M.I.T. He enrolled in a program for electrical engineers but found the curriculum too rigid. By his sophomore year, he had switched to physics.
The summer before his junior year, Dr. Weiss said, he fell in love with a young woman who was a student at Northwestern University. When she eventually found someone else, he grew despondent, he said, failed all his classes and flunked out of M.I.T. in 1953.
He did not leave the campus, though; he found a job as a technician in the Atomic Beam Laboratory, run by Jerrold Zacharias, a physics professor at M.I.T.'s electronics research laboratory.
To create the equipment necessary for the experiments, Dr. Weiss learned how to do sheet metal work, solder and weld, among other tasks, and how to modify pieces of equipment found in metal stockrooms and hardware stores. In his biography, he called it "the art of improvisation in experimental science."
He soon began working with Dr. Zacharias on a cesium atomic beam clock, which became the standard for timekeeping for the National Institute of Standards and Technology and the United States Navy.
The two worked next on an atomic clock that would be precise enough to demonstrate the distortion in time measurement created by differences in gravity, a phenomenon that Einstein had predicted as part of his theory of general relativity. (In short, a clock in a valley will run a little more slowly than a clock on top of a mountain because of gravity.) They were never able to make the clock work, but it piqued Dr. Weiss's interest in gravity and general relativity.
With Dr. Zacharias's help, Dr. Weiss was able to return as a student at M.I.T. to finish his undergraduate degree in 1955 and to then work on his doctorate, which he received in 1962.
After finishing his Ph.D., Tufts University offered Dr. Weiss a faculty position, but he went to Princeton University instead to work with the physicist Robert H. Dicke, who was doing experiments to test general relativity. Dr. Weiss stayed for two years, time that was "profoundly important in my scientific development," he said in his Nobel biography, before Dr. Zacharias lured him back to M.I.T. to join the faculty.
Dr. Weiss received many other awards for his work, including the Einstein Prize in 2007 and the Breakthrough Prize, the Gruber Prize in cosmology and the Kavli Prize in astrophysics in 2016.
He married Rebecca Young, a plant physiologist at Harvard, in 1959, and they had two children, Sarah and Benjamin. They survive him, along with a grandson and Dr. Weiss's sister, Sybille Pearson, who became a well-known playwright and lyricist.
After LIGO began recording cosmic events, Dr. Weiss said, "It only slowly dawned on us that we had made new science, science which is really at the basic core of the fundamentals of what makes nature operate."
With that realization came a new thought.
"With gravitational waves, you have a new way to look at universe," he said. "You can see all that nature has in store. So now comes the question: What do you want to find out?"