This month's edition of Physics World, we've learned in a press release, has an article speculating on how crop circle artists achieve their ever more complicated designs. The author, Richard Taylor, director of the Materials Science Institute at the University of Oregon, speculates that crop circle artists are possibly using the Global Positioning System coupled with lasers and microwaves "dispensing with the rope, planks of wood and bar stools that have traditionally been used."
Microwaves, Taylor suggests, could be used to make crop stalks fall over and cool in a horizontal position — a technique that could explain the speed and efficiency of the artists and the incredible detail that some crop circles exhibit.
Indeed, one research team claims to be able to reproduce the intricate damage inflicted on crops using a handheld magnetron, readily available from microwave ovens, and a 12 V battery.
As Taylor writes, "Crop-circle artists are not going to give up their secrets easily. This summer, unknown artists will venture into the countryside close to your homes and carry out their craft, safe in the knowledge that they are continuing the legacy of the most science-oriented art movement in history."
A little Googling found some crop circle art in Arkansas, on a website weirder than the subject matter at hand. Your guess — bar stools or microwaves?
IT HAS BEEN CALLED TO MY ATTENTION that the Encyclopedia of Arkansas also has an entry on crop circles. Go here for more erudite discussion of the issue.