Three American scientists have just won one of the most coveted awards in science, the 2017 Nobel Prize in Physics, for their headline-grabbing discovery last year of gravitational waves. It was Albert Einstein who predicted these ripples in space many decades ago, but it wasn’t until 2015 when Rainer Weiss of the Massachusetts Institute of Technology and Barry Barish and Kip Thorne of the California Institute of Technology successfully proved him right.

Gravitational waves are faint rippled through the space-time fabric that are caused by cataclysmic events deep in space, like the merger of two black holes. In this case, the waves came from two black holes smashing into each other 1.3 billion light years from us, and the breakthrough led to the discovery of three other instances of gravitational waves since then.

It took this long to detect them because these ripples are so small, almost impossible to detect at all. In fact, they’re smaller than an atom’s width. But now that scientists know how to find them, they’ll be able to observed them much more frequently and hopefully unlock some incredible secrets about our universe.

“LIGO’s discoveries have opened an unparalleled window into our universe and expanded the boundaries of science. The National Science Foundation has supported the goal of detecting gravitational waves for four decades,” said NSF Director France Córdova. “Gravitational waves contain information about their explosive origins and the nature of gravity that cannot be obtained from other astronomical signals. These observations have created the new field of gravitational wave astronomy.”