How to Hunt for Gravitational Waves [Slide Show]
Various experiments seek different versions of this highly sought-after phenomenon
![How to Hunt for Gravitational Waves [Slide Show]](https://static.scientificamerican.com/sciam/cache/file/402B0572-0968-44FE-8B4EE25437D7DEEF.jpg?w=590&h=393)
How to Hunt for Gravitational Waves [Slide Show]
- WHAT ARE GRAVITATIONAL WAVES? Albert Einstein first hypothesized gravitational waves—ripples in the fabric of spacetime—in 1916. When massive objects move around or collide with one another, they disturb the surrounding spacetime like a pebble tossed into a still pond... CREDIT: Swinburne Astronomy Productions
- TYPES OF GRAVITATIONAL WAVES Researchers hunt for three main categories of gravitational waves. Massive bodies moving or merging, such as two black holes or two neutron stars orbiting each other until they collide, as well as the explosion of a supernova, cause ripples strong enough to be measurable on Earth... CREDIT: NASA
- LIGO The Laser Interferometer Gravitational-Wave Observatory, shortened to LIGO, was built to find waves that propagate all the way to the ground on Earth. These waves come from the most powerful events in the universe--collisions of black holes or extremely dense neutron stars... CREDIT: Caltech/MIT/LIGO Lab
- HOW LIGO WORKS Gravitational waves are thought to cause incredibly small but detectable distortions in the positions of objects in the spacetime through which they pass. LIGO's design takes advantage of this fact: Its two L-shaped detectors have three mirrors, one at the end of each leg and one at the point where the legs meet... CREDIT: California Institute of Technology
- LISA PATHFINDER AND eLISA Land-based LIGO is powerful, but being grounded has its limitations. LIGO can only detect high-frequency waves. A space-based interferometer detector, similar to LIGO, could have test masses millions of kilometers apart, creating an experiment targeted to lower frequency, longer wavelength gravitational waves than LIGO's four-kilometer legs could find... CREDIT: ESA-C.Carreau
- PULSAR TIMING ARRAYS Ground-based telescopes search for signs from pulsars that could provide evidence of gravitational waves passing through the universe. Similar to how a gravitational wave–crossing LIGO would alter the length of its legs, gravitational waves rippling along through space can cause the light we see from pulsars to fluctuate... CREDIT: ESO/L. Calcada
