Since 2016, there has been speculation as to whether the detection of gravitational waves, a phenomenon predicted by Albert Einstein (1879–1955) a century ago, was a scientific advance worthy of winning the Nobel Prize. Last year, the achievement was still too recent to win, but in 2017, the Royal Swedish Academy of Sciences acknowledged the contribution of the international scientific collaboration based at the Laser Interferometer Gravitational-Wave Observatory (LIGO) in the USA, whose instruments measured gravitational waves—resulting from the collision of two black holes—for the first time, in September 2015. So far, LIGO has detected the phenomenon, which distorts space-time, on four occasions.
More than a thousand researchers from 18 countries (including Brazil) are involved in the LIGO collaboration, and the academy chose to award the Nobel Prize to three physicists who have played an important role in the history of the observatory. German scientist Rainer Weiss, from the Massachusetts Institute of Technology (MIT), received half of the 9 million Swedish crowns (about US$1.1 million) awarded to the winners. The other half was shared between American physicists Barry C. Barish, 81, and Kip S. Thorne, 77, both from the California Institute of Technology (Caltech). Nobel Committee member and physicist Olga Botner points out that the three scientists selected have highly complementary skills. Weiss had the initial idea and formed the LIGO project in the 1960s. He developed the prototype, demonstrated the principle, and mapped the sources of the sounds that would be detected. Thorne, one of the founders of the LIGO, played an important role in the theory that established what exactly the observatory should look for. Barish, described by Olga as the visionary behind the initiative to increase the sensitivity of the instruments, joined the project in 1994 and was head researcher until 2005.