We know a lot about how gravity behaves, but very little about what gravity actually is. That’s what makes any gravity-related discovery extremely exciting.

One such source of excitement occurred in September 2015, when the Laser Interferometer Gravitational-Wave Observatory (or LIGO for short) made the first ever detection of a gravitational wave – something Einstein had theorised about one hundred years earlier.

Detecting gravitational waves gives astronomers a new way to observe the universe and gain insights into things we’ve already been studying for a long time - not least, a better understanding of gravity itself!

But what makes detection so complicated? And where do lasers come in?

Special thanks to Professor Martin Hendry for his help in the creation of this video.