June 26, 2016 at 02:28AM

Today I Learned: 1) Took apart an old Xbox 360 controller today. It's not difficult, except that it requires a special type of star-shaped screwdriver with a hole in the middle, and it has a secret screw under a barcode in the battery enclosure. The inside is pretty comparable to an Xbox One controller, the biggest difference being that the Xbox One controller comes apart in two stages -- the case comes off to reveal circuitry, thumbsticks, and vibrators, with the buttons and triggers requiring more disassembly to get at. The one-stage disassembly of the Xbox 360 controller is both nice, in that disassembly is easier, and annoying, in that you have to put everything back together at once to reassemble it, which requires a bit more coordination. The two-stage disassembly of the Xbox One is *particularly* annoying because it uses a smaller screw on the interior components, which I don't have a screwcriver for. I suspect the extra hard points on the Xbox One controller helps give it its slightly more solid, smooth feel. Another interesting tidbit -- the right vibrator on the 360 controller has considerably more mass than the left one. Any ideas why? 2) Complex numbers (any number of the form a + bi, where i is the square root of -1 and b is not 0) were discovered in their algebraic form by an Italian mathematician in the mid 1500s named Rafael Bombelli, who ran aground on them while considering the intersections of cubic curves with straight lines (which sometimes has a solution which can really only be found analytically using complex numbers). Complex numbers were then known, but mistrusted, neglected, and/or misused for hundreds of years. Leibniz and Newton both apparently dismissed complex numbers as useless nonsense and probably not real (in the metaphysical sense). What changed? I'm not certain, but according to Tristan Needham, it was the discovery (By Gauss and several other mathematicians independently) that complex numbers have a sensible geometric interpretation on the complex plane. Basically all of the important parts of complex analysis were developed in the 50 years following that discovery, after 250 years of essentially no use of complex numbers since their initial discovery. 3) How to get fingerprinted. You make an appointment with any fingerprint-providing service (there are apparently offices that do nothing but manage official kinds of paperwork, which is where I got mine done). You need to bring some forms, which as far as I could tell only exist so that the information on them can be copied to fingerprinting request software (and for official records, I suppose). There's a little box with a glass panel on the top, illuminated in green. You roll each of your fingerpads across the glass panel, which it scans apparently quite nicely, you pay some money, and the scanner software sends a request to... someone. I don't know who.