Strange gravitational wave echoes may let us probe dark matter

When gravitational waves pass over massive objects, they should create an echo that could allow us to examine objects that we can’t otherwise see, including dark matter

By Leah Crane

The entire universe is suffused with gravitational waves, ripples in space-time caused by the motion of massive objects. As they flow across things like stars and planets, parts of these waves should slow down and travel just behind the original ripple in a kind of echo that could let us examine celestial objects we can’t see – maybe even dark matter.

Only the most massive objects in the universe create measurable gravitational waves. Most of the ones that have been detected so far have come from pairs …