Warping space and time ain’t hard to do. You’re doing it right now, in fact. Einstein’s theory of general relativity says that everything – you, me, even the Earth itself – warps space and time, simply by existing. This astonishing idea turns 100 years old today, and to celebrate, I recorded a short video with the BBC explaining how Einstein discovered general relativity. I hope you enjoy it!

If you want to learn more about general relativity, you can’t do better than Kip Thorne’s incredible book, Black Holes and Time Warps. It’s a few years out of date, but it’s still excellent.

Image credit: Trey Ratcliff