If separated by millions of kilometers and linked by lasers, such a system could then detect the exquisitely small distance changes caused by passing gravitational waves. (scientificamerican.com)
LIGO's instruments are designed to detect passing gravitational waves by measuring minuscule expansions and contractions of space - time — warps as little as one - thousandth the diameter of a proton. (discovermagazine.com)
As passing gravitational waves stretch and compress the space between Earth and the pulsar, the rhythm slightly changes. (sciencedaily.com)