LONDON -- Maybe it's just Britain's summer silly season. Maybe it's something else. Whatever it is, the preoccupation of the moment here is circles. Crop circles.
So what are crop circles? Why is everybody making such a fuss over them -- balanced people, not just hippies, tabloid journalists and UFO tourists?
Maybe it is because they are there.
There is no doubt about that. Earlier this month they began showing up west of here, in Wiltshire. This is where they are always expected, near the circular megalithic monuments at Stonehenge and Avebury.
Last year more than a thousand crop circles mysteriously appeared in various parts of the country. Most were in southern England, but of late they have been been seen farther north, even in Scotland.
A lot of people think the circles are a hoax, practical jokes played on television cameramen and newspaper photographers. But not everyone thinks that way.
No one has ever seen a crop circle actually form, although not for want of trying. Last year a man named Colin Andrews, who runs a group called Circles Phenomena Research, took his electronic sensing gear into the Wiltshire farm lands in an attempt -- backed by the British Broadcasting Corp. and Japanese television -- to record one of the circles being born, or someone surreptitiously creating one.
He mounted his equipment on a hill overlooking 60 acres of corn. But all he got was a faked circle with three concentric rings, believed to have been the work of local pranksters. It had a Ouija board in it, a dead giveaway.
But the skeptics have been as unable to prove that the circles are man-made as the believers have been unable to prove an alternative agency of creation.
The circles tend to be large, perfectly circumscribed areas of flattened rye, barley, wheat, oats -- whatever. There is no preferred crop, it seems.
They are geometrically perfect and always appear without any signs of a human presence, such as flattened areas nearby.
"The circles seem to be evolving," said Dr. Archibald Roy. "Over the past 10 years their number has increased, and their complexity. Instead of just one circle, now you get a large circle with four satellite circles.
"Also, you get circles with rings around them," he said. "It becomes very intriguing. The circles of flattened crops are up to 80 feet across, and the ring is up to 300 feet. The thickness of the ring is only 6 inches.
"If it is a hoax, how do you do this, in the dead of night, with the thickness of the rings only 6 inches, with no other disturbances of the crops? Until someone can demonstrate how they can do that, and do it at the dead of night, the hoax hypothesis is unacceptable."
Dr. Roy is an astronomer at Glasgow University and president of the Center for Crop Circle Studies. The center was founded last Easter by several hundred people -- meteorologists, physicists, lay people fascinated by it all. A lot of farmers are in the organization, Dr. Roy said.
The center's aim is to gather data and then extract a workable theory that people won't laugh at.
The effort, so far, has been unsuccessful, vexing even.
"I have no theory about this," said Dr. Roy. "This is what is flabbergasting me. When you study a research field for as long as seven years, you usually have some theory."
At least three books have been published here about the crop circles. The author of one, Dr. G. T. Meaden, a physicist and meteorologist at Oxford University, has suggested that the circles might be created by small whirlwinds, formed by a combination of the Wiltshire topography and cool air over the region.
Dr. Roy, while recognizing Dr. Meaden's expertise in such matters, discounts the theory. "I must say most people do not agree with him because last summer there were circles joined by corridors with arms coming out, some of them about one-fifth of a mile long.
"One appeared last year consisting of a large circle and three rings about it. A fourth ring was added about five days later. Each ring was only about 5 to 6 inches in diameter. Now, it's not likely the whirlwind said to itself, 'Uh-oh! I've got to go back and add another circle.' "
Dr. Meaden was unavailable for comment Friday. According to his wife, he was out inspecting another circle that had just appeared.
Dr. Roy believes the circles have probably been appearing for thousands and thousands of years, but much less frequently. "Otherwise they would have become a part of the people's folklore."
He suggests that since they might have been known to the people who lived in the region some 3,500 years ago, they could have been the influence for Stonehenge and Avebury.
As to their increasing frequency, he said: "I think something is happening."