Friday, December 03, 2010

It adds up!

Went today with my mathematician friend J to see some of the oldest mathematical artifacts around, in a sweet little exhibition at our friend the Institute for the Study of the Ancient World called "Before Pythagoras: The Culture of Old Babylonian Mathematics." In display were cuneiform clay tablets from 4000 year old tablets, including two J knew from math history and ethnomathematics text books. The famous Plimpton 322 (above), which scoops the Pythagoren theorem, and YBC 2789 (below), which has a remarkably close approximation to the square root of 2... The real pleasure, though, came as we slowly learned how to make out a few of the numbers (conveniently the right column above goes 1-15) and so to actually see what was going on. The next challenge, though, is that the Babylonian numbering system (which I learned about in J's ethnomathematics class) is sexagesimal - it's base 60! We felt like little Champollions making deciphering and then confirming that 1, 24, 51, 10 is in fact the number inscribed along the central diagonal above - and that 1 + 24/60 + 51/3600 + 10/216000 indeed adds up to something very close to the root of 2 - 1.4161713! (We confirmed this on our own palm-shaped calculation device, J's iPhone.) How did they figure it out?!Great fun - and it was just the start of an afternoon of cultural stimulation, which continued with the John Baldessari show at the Met, and then, after J had to head home to New Jersey, two more Met shows for me, both splendid, The World of Khubilai Khan and Jan Gossart. I haven't energy to tell you about them, but here are two piece from each, picked more or less at random: "California Map Project" (1969), "The Spectator is Compelled..." (1966-68); model of a stage (1210), near life-sized wooden arhat (14th c.); "Deposition from the Cross" (1525), "Portrait of a Man (Jan Jacobsz. Snoek?)" (c. 1530). An amazing feast.