Monday, December 18, 2006

Putting the "Extra" in "Extraordinary"

One of the best Christmas presents I ever received was given to me last year by my wonderful wife: The New Yorker magazine on DVD, every issue ever printed ... except that it's always about a year behind. I love the magazine but don't subscribe because I know I can't keep up with it, which is silly because it's fairly easy to keep up with 50 issues a year compared to catching up on 80 years of back issues.

Anyhow, this explains why I'm only just now reading a 2005 article by Richard Preston called Capturing the Unicorn. The thing is an unintentional catalog of the extraordinary. First, there's "The Hunt of the Unicorn," the seven tapestries "woven from threads of dyed wool and silk, some of them gilded or wrapped in silver, around 1500" and owned since 1937 by the Metropolitan Museum of Art. They are "the most beautiful tapestries in existence," are "among the great works of art of any kind," and "their monetary value today is incalculable." They were moved in 1998 from the Cloisters to the Met itself to be cleaned and repaired. (I'm thinking art heist movie -- are you?)

Second, the linen backings, which had deteriorated, had to be removed, performed by a team at the Met "using tweezers and mangifying lenses." And just so you know, these tapestries aren't small: they're 12 feet tall, and some are 14 feet wide. Did I mention there were seven of them? Preston estimates it probably took about seven years to make them. Imagine trying to take off the backings without harming them. (Would you be nervous? Naah, I didn't think so.)

Third, the Met's chief photographer has a goal of making a "high-resolution digital image of every work of art in the Met's collections. The job will take at least twenty-five years ..." Nothing like having a goal. Anyway, her team had to photograph the tapestries in sections. It took two weeks and the images filled over 200 CDs. The plan was to stitch the images together in Photoshop.

Fourth, when it turned out the images couldn't be stitched together, two mathematicians, Gregory and David Chudnovsky, came to the rescue. The pair are brothers and "insist they are functionally one mathematician who happens to occupy two human bodies." Preston refers to the two as "the Chudnovsky Mathematician." They took the CDs from the Met (yes, there was a predictably hilarious incident where one of them accidentally left a whole bag of the CDs at the grocery store) and fed the data into their home-built supercomputer ... but couldn't stitch the images together at first. Why? Because a tapestry is not a 2-D object, but a 3-D one. The warp of it changed shape over tme, responding to changes in humidity and heat. Hour by hour, as the photographers worked, it expanded and contracted, its edges shifting slightly, and "the gold- and silver-wrapped threads changed shape at different speeds and in different ways from the wool and silk threads." On top of this, the photographers had placed a sheet of paper underneath the sections they photographed, and as they moved it, they stretched the tapestry slightly, making it ripple. All of which added up to a heckuva math problem.

Solve it the Chudnovsky Mathematician did. Now the Mathematician is working on a supercomputer for the US government that "will contain two million processors and fourteen thousand hard drives. It will use two and a half million watts of electricity -- enough to power a few thousand homes. Two thousand gallons of water per minute will flow through [its] core ... to keep it cool. If the pumps fail, it will melt down in less than ten seconds."

Sorta puts our own puny ambitions into scale, don't it?

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