Rainer Weiss obituary: Nobel laureate who pioneered the technique that detected gravitational waves

"In 1972, German-American physicist Rainer 'Rai' Weiss showed that laser interferometers - devices that measure tiny changes in distance using beams of light - could, in principle, detect gravitational waves. These ripples in the fabric of space and time were first predicted by Albert Einstein in 1916 as part of his general theory of relativity. Although prototype detectors already existed, most scientists thought the task was hopeless: the waves were so faint that they shifted matter by amounts thousands of times smaller than the nucleus of an atom. Weiss demonstrated that, with extreme precision and technological innovation, they could be detected."

"More than 40 years later, in 2015, gravitational waves were observed directly for the first time. This breakthrough earned Weiss one-half of the 2017 Nobel Prize in Physics, the other half being shared by his colleagues Kip Thorne and Barry Barish. Gravitational waves are produced by violent cosmic events, such as black-hole collisions or star explosions. Einstein had predicted them reluctantly, dismissing them as "of no consequence" because they seemed impossible to detect. Weiss and Thorne disagreed. They campaigned for the US National Science Foundation to fund large-scale detectors, leading to the construction of the Laser Interferometer Gravitational-Wave Observatory (LIGO), with twin facilities in Washington and Louisiana; it was completed in 1999."

"Weiss was known for his blunt humour. After winning the Nobel Prize "for decisive contributions to the LIGO detector and the observation of gravitational waves", he joked to friends: "This is going to screw up my life for a year." The irreverence was intentional. Born in Berlin in 1932, Weiss came from an intellectual but unsettled family. His father, a Jewish communist doctor, and his mother, a Christian actress, fled Nazi Germany when Rai was still a child. The family escaped first to Prague and later to New York City, arriving in 1939."

Rainer 'Rai' Weiss proposed in 1972 that laser interferometers could detect gravitational waves by measuring minuscule distance changes with light. Gravitational waves were predicted by Albert Einstein in 1916 as distortions of space-time produced by violent cosmic events like black-hole collisions and supernovae. Weiss showed that extreme precision and technological innovation could overcome the tiny displacements previously deemed undetectable. More than 40 years later, in 2015, direct observation of gravitational waves occurred, and Weiss shared the 2017 Nobel Prize in Physics with Kip Thorne and Barry Barish. Weiss helped campaign for funding that enabled construction of the LIGO observatory, completed in 1999.

Read at Nature