From time to time, I take a break from wasting time reading about useless things to read about theoretical things. Like gravity.

I’ve never really understood gravity. I love the idea that any two bodies with mass attract one another, and enjoy the idea of calculating the force of gravity that I exert on the things around me. But what is the force? How does it behave?

The other day I found an analogy. It was in an article I was reading on scientist Ron Mallett, who is attempting to build the world’s first time machine. Unlike others who have set the same goal for themselves, Mallett is at least a respected physicist, and is submitting his theoretical mathematics to peer review, rather than selling them to tabloids. He concedes that time travel to a point in time prior to the invention of the world’s first functioning time machine would be impossible.

But the part of the article that grabbed me was this picture:

Gravity

Gravity, it turns out, is not a force at all. It is nothing that can be likened to a magnet pulling two bodies together. Rather, as general relativity would have it, large concentrations of mass cause a bending of spacetime, which can be likened to a bowling ball on a trampoline.

Of course, I take this type of analogy for what it must inevitably be: a bad approximation of extremely complex mathematics. But it was nonetheless enlightening for me.