I can’t quite remember his name with certainty, but he lived in the house with the green shutters at the tip-top of the hill. He was right across the street from the bus stop.

One day he says “If nothing can move faster than the speed of light, explain this…” Then he gives the supposedly Einstein-derived thought experiment in which you imagine a train moving at the speed of light, inside which is a horse who moves from the back of the train to the front, and then add to this scene a horse beside the train who is pacing the horse in the train.

I took his point to be the classic midwestern point of “Einstein is wrong” sentiment (falling within the broader category of “bein’ smart ain’t nuttin’”), because the horse beside the train is obviously going faster than the speed-of-light train.

But I am working through Einstein’s own The Evolution of Physics and the truth is far different. Whether the kid knew it or not (it is possible I totally misread the moment), the thought experiment is not the one Einstein proposes (at least in this book) but does capture the concept—being relativity. In short, the speed of light is the limit. The horse beside the train is not going faster than the speed of light. This is Einstein’s discovery or theory or whatever you want to call it.

As with all knowledge, it is the presuppositions that matter and the thought experiment is based on the presuppositions of mechanical physics, whereas—it would seem—reality is not. (Reality is not based on mechanical physics—at least not entirely.)

And, yes, like you, I do have a bit of “so what, Albert?” in me. But then I remind myself that the point of my reading is not to “learn to care”, but to learn so that I can call out BS when I see it.