High-tech techniques such as GPS could be behind the appearance of crop circles, says physicist Richard Taylor of the Materials Science Institute at the University of Oregon.
Crop circles first started appearing in the 1970s, and over ten thousand have now been reported - mostly in the UK, although they've appeared in 25 other countries too.
Earlier crop circles tended to be simpler, and their creators have demonstrated how to do it by crushing plants with boards.
But today's crop-circle designs are more complex, with some featuring up to 2000 different shapes. Mathematical analysis has revealed the use of construction lines, invisible to the eye, that are used to design the patterns.
"Crop-circle artists are not going to give up their secrets easily," says Taylor.
"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."
And, according to Taylor, these artists may well be using the Global Positioning System (GPS) as well as lasers and microwaves to create their patterns, dispensing with the traditional rope and planks of wood.
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.
"It may seem odd for a physicist such as Taylor to be studying crop circles, but then he is merely trying to act like any good scientist – examining the evidence for the design and construction of crop circles without getting carried away by the side-show of UFOs, hoaxes and aliens," says Matin Durrani, editor of Physics World, in which Taylor's report appears.