The 2015 detection of gravitational waves is often heralded as one of the most important scientific discoveries in a century. It's no surprise, then, that the Royal Swedish Academy of Sciences has awarded the 2017 Nobel Prize in Physics to scientists at the LIGO/Virgo Collaboration for making that groundbreaking discovery possible.
First predicted by Albert Einstein over 100 years ago, gravitational waves are ripples in the fabric of spacetime itself, caused by the acceleration of objects. Technically, anything with mass creates these waves, but it takes cataclysms on a gigantic scale, such as the merging of two black holes, to generate gravitational waves strong enough for us to detect – and even then, by the time they reach Earth, the disturbances are occurring on a subatomic scale.
To detect ripples that tiny, scientists use laser interferometers. These instruments work by splitting a laser beam down two paths and reflecting them back, before rejoining and analyzing them for any perturbations during the journey. These can indicate that the space between the mirrors has been warped, thanks to the influence of gravitational waves rolling past.
The Laser Interferometer Gravitational Wave Observatory (LIGO) was designed and built specifically to observe that phenomenon, and in September 2015 the very first detection was confirmed. The gravitational waves spotted were created 1.3 billion years ago, when two massive black holes collided, and the resulting disturbances were picked up by both LIGO facilities in the US, located in Washington and Louisiana.
Since then, gravitational waves have been observed three more times, with the latest detection occurring in August 2017, with the help of the Virgo facility in Italy.
The 2017 Nobel Prize in Physics has been awarded to three scientists who played key roles in the observation of gravitational waves. One half of the award went to Rainer Weiss, who designed the laser interferometer in the 1970s that allowed the phenomenon to be detected. The other half was awarded jointly to Barry C. Barish and Kip S. Thorne, who were instrumental in bringing the LIGO project to completion.
Nobel Prizes in other fields are due to be awarded throughout the week, following the announcement yesterday that the 2017 Nobel Prize in Physiology or Medicine has been awarded to the team of scientists that identified the molecular mechanisms of our biological clocks.
Source: Nobel Prize