Watching the Universe Dance

Gravitational waves, Lucy hunts for asteroids, the origins of Oumuamua, and Boeing’s problems on the launchpad

Oumuamua, an artists impression. Credit: European Southern Observatory/M. Kornmesser

Gravitational waves are one of the stranger predictions of Einstein’s theory of gravity. They are, effectively, distortions in the very fabric of the universe, rippling out from some of the most intense events in the cosmos. Such waves are constantly washing over the Earth, though our ability to detect them has so far been limited.

The first confirmed sighting of a gravitational wave came just six years ago, at an advanced American detector known as LIGO. Researchers think it originated more than a billion light years away, from two black holes spiralling towards a collision. Since then another two dozen or so have been spotted, most coming from similarly extreme events.

That is a mere fraction of the gravitational waves that we could have seen, had we possessed more powerful detectors. Right now we only see the largest waves, equivalent to powerful tsunamis racing across an ocean. If we could see the smaller, everyday waves, then astronomers could trace distant black holes, watch neutron stars and even hear echoes of the big bang itself.

Developing detectors capable of doing that is hard. Gravitational waves, even from immense…