Scientists have two ways to spot gravitational waves. Here are some other ideas

To see all the gravitational waves the cosmos offers, scientists are thinking big — and small

Illustration of two black spheres orbiting in a grid with ripples that represent gravidational waves

Gravitational waves (illustrated) are produced when massive objects like black holes or neutron stars orbit one another. These waves vibrate the fabric of spacetime (grid).

MARK GARLICK/SCIENCE PHOTO LIBRARY/Getty Images Plus

Until recently, gravitational waves could have been a figment of Einstein’s imagination. Before they were detected, these ripples in spacetime existed only in the physicist’s general theory of relativity, as far as scientists knew.