A fly-sized airplane constructed in John Wood's lab
A thin paperback enjoys an honored place on my bookshelf. It is Vincent Dethier's To Know a Fly. Over the years since it was published in 1962, I have read this book at least a dozen times. It is a wonderful monograph that tells us quite a bit about flies but still more about the scientific enterprise. And remarkably, it is written in the kind of clear English that unfortunately we do not expect from scientists. (Scientific American recommends it "for anyone twelve or older.")
I offer parts of two paragraphs that characterize Dethier's writing:
"To stay airborne and move forward, the fly must beat his wings as much as two hundred times a second. By comparison, the hummingbird beats about seventy-five times a second and the fastest repetitive muscular contractions that you and I can produce occur at the rate of about ten times a second.
"The fly has other wondrous accomplishments, too, not the least of which is being able to land on the ceiling. For years, controversy raged as to whether he managed this by executing a half-roll or an inside loop. As a matter of fact, he does neither. He flies close to the ceiling in a normal position, then reaches up and back over his head with his front feet till they touch the ceiling, whereupon he somersaults over into position."
Dethier, who wrote another outstanding book, Crickets & Katydids: Concerts and Solos, which won the John Burroughs medal for distinguished science writing, died in 1993 after a productive career as an insect physiologist at Johns Hopkins and Princeton.
Today two young scientists, Michael Dickinson and John Wood, have taken up Dethier's research and extended his work in interesting ways.
Dickinson teaches at the University of California at Berkeley. Based on his early research career, he has received one of the $500,000 "genius" grants given by the MacArthur Foundation to creative individuals "who provide the imagination and fresh ideas that can improve people's lives and bring about movement on important issues."
His focus is on the flying abilities of insects in general and flies in particular. "Flies are the most accomplished fliers on the planet in terms of aerodynamics," he says. "They can do things no other animal can. They are especially adept at takeoffs and landings, their skill far exceeding that of any other insect or bird."
Dickinson has built some remarkable equipment including photographic tools that allow him and his students to study their flights. His evidence shows clearly that these insects' tiny brains still allow them to perform activities in a time scale hundreds of times faster than our own.
One rather frivolous outcome of Dickinson's studies tells us why we have so much trouble swatting flies. His high-speed photography shows that the fly, seeing the looming swatter, moves the middle two of its six legs into position to jump away from the swatter as it descends. It then springs aside. All this takes place in less than a tenth of a second.
That may be a superfluous result, but it has an immediate application: you can take from it some thoughts in how to aim your swatter.
The other fly researcher, John Wood, teaches at Harvard. This year he won the National Science Foundation Career award and was named by Technology Review Magazine one of the world's top 35 young science innovators.
Wood's research, as he describes it, "focuses on design, fabrication, control, and analysis of biologically-inspired microrobots," in other words on insect-sized flying machines whose mechanics are similar to those of insects. He has already constructed one such airplane less than an inch long.
I suspect that some readers may feel that people like Dethier, Dickinson and Wood don't deserve our support, let alone our praise. You may even feel that they have earned William Proxmire's Golden Fleece awards for wasting public money.
I disagree and I offer two of many reasons. First is the obvious development of spy planes. Second, fly reactions take place at millisecond speed, that is within .001 second intervals. Determining how these tiny brains can control such rapid actions can have important applications to such things as robot control and protection against industrial accidents.-- Gerry Rising