A powerful scientific tool set to come online in 2015 could help scientists spot gravitational waves: ripples in space-time born from violent cosmic crashes light-years from Earth.
Image: A still frame from a computer animation shows two binary neutron stars coalescing into a black hole. Taken from the video, “LIGO, A Passion for Understanding,” Credit: Kai Staats
The instrument, called LIGO (short for Laser Interferometer Gravitational-Wave Observatories), uses lasers to hunt for the gravitational aftermath created by two massive objects — like a neutron star and a black hole — colliding. Scientists theorize that, like a rock dropping into a pool of water, the fabric of space and time can ripple, sending out these gravitational waves across the universe at the speed of light. Understanding those waves could help scientists learn more about black holes.
The $205 million LIGO can potentially detect these gravitational waves from Earth. The interconnected LIGO observatories in Washington State and Louisiana make use of two 2.5-mile (4 kilometers) arms. A laser beam is split down the arms that are equipped with specifically placed mirrors. In theory, if a gravitational wave comes into contact with the instrument, it would change the length of one beam in relation to the other.