Brad DeLong has an extraordinary economics blog. You can find there lots of economic history, center-left politics, and also unique compositions like a Socratic dialog concerning the Greek fiscal crisis, jokes about the Valar, and who knows what else.

This weekend, he posted about the (lack of) philosophical foundations of quantum mechanics. [1] That’s an interesting topic in itself, but what struck me was the fact that he was quoting from an optically-scanned PDF of a magazine article by John Bell.  The OCR program wasn’t invented for physics, so when we do things like stick a greek letter into an english sentence, it gets confused. But here’s the thing. It wasn’t hard to read.  Because I’ve been through the arguments a dozen times before, it was easy to figure out that”If we take advantage of the indistinguishability of p and p…” actually has two ρ’s in it, and one of them has a circumflex over it.  (By symmetry of the copulating conjunction, it doesn’t matter which one. [That’s a physics joke])

When I look at a medieval document, I can usually recognize a bunch of the words. But understanding full sentences isn’t as easy, so I find a paper by a medieval scholar who interprets it. How do I know she got it right?  This little exercise in point-of-view reversal has given me a lot more confidence that they know what they’re talking about.

[1] If you’re wondering why, a speculation: Prof. DeLong frequently discusses the problems with dynamic stochastic general-equilibrium models of the macroeconomy. This may be a case where he’s looking at physics for guidance about how to stay connected to reality when your equations are fiendishly complicated.