It's two detectors, each of which has two tunnels at right angles to each other ...

		yanowitz on Feb 11, 2016 \| parent \| context \| favorite \| on: Gravitational waves detected by LIGO It's two detectors, each of which has two tunnels at right angles to each other (and generate an interference pattern when a gravity wave distorts the tunnels length).

Oops, I meant two.