For a mathematician, Jerry Bona spends a lot of time perfecting a purely physical skill. To demonstrate his prowess, he grabs a plastic plate and purposefully swishes it through the four inches of water that sits in the singular glass canal dominating his laboratory. The canal has the height and depth of a large home aquarium, but it runs the entire length of the 60-foot wall to which it is bolted with bright yellow metal ribs. Bona's swish produces a single swell of water, about two feet long and a few inches high. It sails down the enclosure 60 feet to the other end, crashes into the glass wall, then bounces back to begin the return trip, looking none the worse for wear.
"Not bad, huh?" says Bona, gazing with obvious affection at the wave, which continues to rebound through the odd water tank, back and forth, again and again, keeping its shape and most of its size. It takes several minutes before the water is fairly still again. "Most mathematicians wouldn't walk two blocks to see an experiment, much less build their own laboratory," he jokes.
The $100,000 water tank is the pride and joy of Bona's Penn State lab, and he enjoys showing it off. It was constructed two years ago in what used to be a women's dormitory, a modest building sheltered by the last remaining large stand of elm trees in North America. The tank is small by public-aquarium standards--though a bored student once sneaked goldfish into it--but what it lacks in volume it makes up for in precision: adjustable supports straighten the walls of the tank to a tolerance of a ten-thousandth of an inch to avoid energy-robbing and shape-deforming bends, and the water is distilled, filtered, and skimmed to remove dust, which can also interfere with the waves. The computer-controlled wave generator is still being perfected, so for now Bona makes do with his plate, having more or less mastered the fine art of producing waves manually. "It takes some practice," he admits.
It's not just any wave that Bona has sweated to perfect. The wave that bounces off walls with impunity and refuses to fade is known as a soliton. Bona studies the behavior of solitons so that he can come up with better mathematical tools for analyzing these strange waves--tools of great interest to physicists, biologists, and other scientists. Why would scientists want to analyze solitons? Because the immortal wave has turned up almost everywhere researchers have looked for it, from the behavior of complex biological molecules to gigantic, bizarre conglomerations of matter that might be lurking in or between galaxies. "Solitons haven't turned up in theology or sociology yet," says Alan Newell, a University of Arizona physicist specializing in the durable lone wave, "but they're just about everywhere else."
