Time

“Time flies like an arrow; fruit flies like a banana.”

A funny, clever line, usually attributed (with, so I gather, absolutely no basis in fact whatsoever) to Groucho Marx. Funny, clever, but also based, at best, on a half truth.

Does time fly like an arrow? Sort of. Really it flies the way an arrow flies before its momentum runs out and it’s brought to earth by the inexorability of gravity, but that’s just nitpicking. We get the idea. Take gravity out of the equation and let’s say the arrow flies fast and true, neither deviating from its path nor decelerating from its steady speed. That is what time does. Or at least (and I am extremely ill qualified to be passing judgement on the complexities of the space-time continuum) that’s how we perceive and measure it. Linear and unwavering. Just look at a clock.

But.