Wild gravity

I like to think of myself as scientifically literate, so I’d always been a bit embarrassed that my knowledge of General Relativity was rather superficial. High school physics classes and popular science books had taught me that e=mc2, that gravity is caused by matter warping spacetime, and that clocks slow down when you travel at the speed of light, but until recently I’d have been pushed to explain exactly why these things were so.

Then, towards the end of last year, I watched the movie Interstellar, the plot of which turns on the time-stretching effects of extreme gravitation, which inspired me to fill in this gap in my education. So I’ve read various textbooks, and Einstein’s own pamphlet on the subject, and while, if I’m honest, the mathematics are still a bit opaque to me, I think I’ve got a fairly good grasp of the basic principles.

Just in time too; the day after I finished the Einstein book, the gravitational waves he predicted were finally discovered (or the discovery was announced, the actual event having taken place last year). It’s nice to feel that one understands the importance of scientific advances like this, but even in a state of relative ignorance it would be hard not to be awed by a story that involves black holes spiralling at near the speed of light before crashing to release the energy of a billion trillion stars in the blink of an eye. The fact that we can hear the echo of this cataclysm a billion years later is nothing short of amazing. Despite all the evidence to the contrary, humans are pretty smart.