`A Random Light Meandering'

I knew a computer science professor who now works, I think, for Google. He was an interesting fellow who defied many CS stereotypes. He read books outside his field, for instance, and spoke in complete sentences. Ten or twelve years ago as I was walking across the engineering quadrangle toward the parking lot, I noticed him kneeling on the sidewalk outside the mechanical engineering building. He seemed to be looking at something in the grass. As I approached, I saw he was studying a fire-ant mound. He said two words: “Brownian motion.” The phenomenon is named for a Scottish botanist, Robert Brown, who, in 1827, was the first to describe the random fluctuations of pollen particles suspended in a fluid. Strictly speaking, swarming ants are displaying Brownian motion only in a metaphorical sense, but the prof’s observation has stuck with me and I remember it whenever I see a swarm of ants or bees. I remembered it also when reading Howard Nemerov’s “The Crossing” (Gnomes and Occasions,…