PARIS – When Albert Einstein forged the bedrock theory of modern physics 100 years ago, he had no computer — few homes even had telephones. Yet it took one of the most sophisticated science tools ever built to prove an idea he crafted with little more than paper, a fountain pen and a sharp mind.
Physicists’ announcement Thursday that they had detected gravitational waves confirmed what had until now been a key unproven element of Einstein’s general theory of relativity, published in 1916.
The discovery by the Laser Interferometer Gravitational-wave Observatory (LIGO) of gravitational waves from the collision of two black holes 1.3 billion light-years away offers astrophysicists a new way to explore the universe.
The twin LIGO instruments in the states of Washington and Louisiana use a split laser beam to detect infinitesimal changes in length between L-shaped arms as gravitational waves pass through.
Two additional LIGO detectors are scheduled to begin operation by 2018 in Japan and 2019 in Italy. Takaaki Kajita, a Nobel laureate in physics will search for the waves using Japan’s detector, called Kagra, in Gifu Prefecture.
The new facilities will help astrophysicists pinpoint the precise location of cataclysmic events such as black hole mergers and supernovas.
Last December, the European Space Agency launched a small lab called Lisa Pathfinder to test the technology of seeking gravitational waves in space, where the detector’s arms can be a million kilometers long and there are no background vibrations to interfere with measurements.