Listening to the Universe-detector diagram

Listening to the Universe-detector diagram

diagram of how gravitational wave detector works

A LIGO detector works by measuring minute changes in the distances traveled by twin laser beams. The two beams, formed by splitting a single beam, are sent through 4-kilometer-long arms at right angles to each other. At the end of each arm is a mirror that reflects the beam back to the starting point. If a gravitational wave passes through, it will alter the length of one arm by a tiny amount, and the beam in the lengthened arm will arrive back at the sensor slightly later than the other beam.

IMAGE: Caltech/MIT/LIGO Lab