Anyway...I'm having to study a lot of astronomy material in preparation for this conference in Hogsmeade next week. Not only must you calibrate to the sun's position when making solar-based potions, but you must also calibrate for things like sunspot activity and so forth, because sunspots will make a potion more potent. This used to be a phenomenon that was unexplained before the invention of telescopes, but now it can be accounted for and its effects reliably predicted.
Then there's the speed of light calculation and all sorts of other stuff. It's a wonder to me that Snape gets any brewing done, in the midst of all the arithmancy.