Goodbye Rai Weiss

We are deeply saddened to hear about the passing of Rainer Weiss, one of the fathers of gravitational wave research, founder of the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Nobel Prize laureate in physics for the detection of gravitational waves.

Rainer Weiss, known to most as ‘Rai’, was professor emeritus at MIT, where he graduated and received his doctorate in ’62. Weiss conceived of LIGO for detecting gravitational waves, and was later a leader of the team that built LIGO and achieved the first-ever detection of gravitational waves. In 2017 Weiss was awarded the Nobel Prize in Physics, along with Barry C. Barish and Kip S. Thorne, “for decisive contributions to the LIGO detector and the observation of gravitational waves”.

During his remarkable career, Weiss also developed a more precise atomic clock and figured out how to measure the spectrum of the cosmic microwave background via a weather balloon. He later co-founded and advanced the NASA Cosmic Background Explorer project, whose measurements helped support the Big Bang theory describing the expansion of the universe.

In addition to his extraordinary research achievements, which earned him the most prestigious of awards, he had a great passion for teaching. It was while preparing one of his lectures that, at the end of the 1960s, he had the idea of an exercise for his students: detecting gravitational waves with an interferometer. From that idea, LIGO would be born.

“We mourn the passing of Professor Rai Weiss, a brilliant physicist and founding figure of gravitational wave science.”, said INFN researcher and Virgo spokesperson Gianluca Gemme, “His vision, perseverance, and deep insight shaped the field and inspired generations. The Virgo Collaboration is profoundly grateful for his legacy and enduring impact.”

In a few days the first detection of gravitational waves will be ten years old, a significant anniversary that will become a moment of sharing to celebrate Rainer Weiss’ extraordinary scientific legacy.

Photo credits: MIT/Bryce Vickmark