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IF YOU had stood on the slopes of the Iron Age hillfort at Bratton,
Wiltshire, near the famous Westbury White Horse, at the end of July 1987,
you would have seen a pair of circles in a field of wheat below, 4.5 and
8.5 metres across. On closer inspection, you would have found that the wheat
within the circles was flattened like a carpet, with the straws aligned
in anticlockwise spirals flowing out from the centre to the abrupt edge.
And if you had kept an eye on that field for the next few weeks, you would
have seen further strange patterns.

A week later a line of three bigger circles appeared at the other side
of the field, only 250 metres away. The wheat was swirled clockwise in two,
and anticlockwise in the other. A few days afterwards, two more arrived,
the larger wholly obliterating the smaller circle of the original pair.
Between 20 and 22 August, a set of five circles arranged in the pattern
of the spots on a die, joined this array shortly before the harvest started.

In a matter of three weeks these three acres of southern England had
suffered four independent visitations from some destructive aerial agent.
Furthermore, there was another group of three mystery circles two fields
away, directly below the White Horse. A double-ringed circle had appeared
half a kilometre to the east, and yet another big circle, 15 metres across
with an elliptical ring alongside, lay a kilometre westward. All these circles
appeared beneath the north-facing chalk scarp of Salisbury Plain. What can
be so peculiar about this corner of rural England that it attracts such
frequent and bizarre happenings? The appearance of circles is not, in fact,
limited to the edge of Salisbury Plain. They crop up across southern Britain,
and have been reported from as far north as Grampian in Scotland. The oldest
anecdote that I know of goes back to the Middle Ages, when ‘mowing devils’
were held responsible. A farmer asked a workman what he would charge to
mow his field. The mower’s price was too high, and the farmer told him that
the Devil himself should mow his oats before he should have anything to
do with it. Next morning, it looked as if the Devil had taken the farmer
at his word, for his crops were flattened in the familiar circle.

All sorts of origins have been suggested, from hoaxers to funghi and
even extraterrestrials. There is no possibility that all these complicated
patterns are hoaxes, nor that the circles are in any way unnatural. For
example, they are not the result of vortices created by aircraft. Everyone
who examines flattened circles on site is impressed by the swirling spiral
pattern of the corn, the many interwoven layers, the twisted straws and
the double centres so often seen – evidence enough to demonstrate how impractical
it would be to make them.

I made the first scientific investigations into the circles in August
1980 near the Westbury White Horse, and I have worked on the problem every
year since, surveying hundreds of circles and compiling statistics on more
than a thousand. This total includes accounts of about a hundred circles
from between 1918 and 1979. Of the 303 circles documented during 1989, five
also had a single ring, one a double ring and one a triple ring. 1989 yielded
16 sets of circles in the intriguing quintuplet pattern. The outer spots
of these complex arrays are sometimes joined by a ring. Single circles range
from 0.3 metres to over 60 metres across. When they form regular arrays,
the patterns can spread over as much as 90 metres. How can such remarkable
patterns be a product of forces in the atmosphere? The answer comes from
the interaction between air flowing in the few hundred metres above the
ground and the topography. The flow of air can become turbulent downwind
of mountains and hillsides, and form small-scale vortices. When these eddies
break down, they can move close to the ground, and sweep out the circles
in the crops. If the spinning air builds up an electric charge, this neatly
explains the humming noises and lights that eyewitnesses have recorded when
they have seen the circles form.

It seems that the eddies form best when air settles into stable layers
in the few hundred metres above the ground. Another important factor is
an undulating landscape which often, but not always, features a prominent
escarpment or isolated hill, low enough to lie within this boundary layer.
A temperature inversion, when a layer of cool air settles in a pool near
the ground at night, trapped beneath a layer of warmer air, is a good way
to achieve this stable stratification. The hills of southern Britain, commonly
between 30 and 150 metres high, may be the best size for the effect. In
fact, we have found that circles can appear as far as 6 kilometres downwind
of such topographical obstacles.

What seems to happen is that an eddy vortex or trailing vortex develops,
in the form of a column of air spinning inward and upward about a vertical
axis. These vortices are often inherently unstable because they can form
when a short-lived weather front passes by. I think that the high frequency
of weak fronts such as cool sea-breeze fronts over southern Britain, in
conjunction with the landscape of gently rolling hills, goes part way towards
explaining the high density of circles in fields of corn, wheat and rape
there.

Physical meteorologists John Snow of Purdue University, in the US and
Tokio Kikuchi of Kochi University, Japan, have analysed what happens when
this sort of circulation, known as an eddy vortex, becomes unstable and
breaks down. Their conclusions have been reinforced by George Bathurst,
a retired engineer, who looked at the problem from an aerodynamic point
of view. Snow and Kikuchi found that when such a vortex becomes unstable,
a ring-shaped, horizontal bulge develops in the column. This ring-vortex
moves downward until it hits the ground, and collapses in on itself. Other
researchers have seen this mode of vortex behaviour in laboratory experiments
with smoke rings. Witnesses have observed rings in waterspouts and tornadoes,
when vapour marks out the shape of the clouds. In drier air, there may be
no vapour to give visible clues, but the air spins in the same way.

When such a ring-vortex settles in a field of corn, it sweeps out a
ring of damage as it expands, swirling the crop into the characteristic
spiral pattern. Keith Moffat at the University of Cambridge has worked on
the theory of swirling ring-vortices, in which the pattern of airflow constantly
moves around the ring. I think that this swirling motion holds the key to
the spiral arrangement of crops within the circles. A stable ring-vortex
would deflect the corn in straight lines around the circle, but the swirling
would give the curves that are so characteristic.

Experiments using smoke-rings, by H. Yamada and his colleagues show
what happens when a ring-vortex moves close to a wall. I have interpreted
this work to visualise what happens when the descending ring-vortex meets
a field of crops. First, the ring spreads out sideways, sweeping the corn
into a spiral. The flow of air along the ground then divides into two, setting
up a vortex rotating in the opposite direction as the original one dies
out. The second, counter-rotating, vortex terminates the swirling abruptly,
and accounts for the sharp edge of the crop circles. The combination of
two oppositely-directed airflows accounts for the complicated directions
of swirling seen in some of the circles. This prevents the primary ring
from flattening more corn and helps to generate the sharp edge.

Some circles have pyramids of corn standing upright at the centre of
the spiral. In others a former standing centre has been removed when the
vortex has drifted, or because of oscillation caused by a cross-wind. In
contrast, there are examples in which the centre has been struck exceptionally
hard, with no evidence of a vanished ring. Everything is swept clear in
a radial direction.

At the other extreme, a small percentage of vortices must descend gently,
in order to explain ‘brushed circles’, in which the crop has been skimmed
rather than punched flat. So, overall, more than one vortex mechanism may
be involved. In the complex circle sets, like the quintuplets, the links
between circles, whatever their origin, must be powerful because they operate
over distances of tens of metres. The longest pattern so far is 90 metres
across.

Furthermore, and probably too often for it to be entirely due to chance,
the centre is sometimes on a patch of bare earth that was there before the
circle formed. This suggests that the vortex may have aimed for the soil,
following minor variations in the local electric field, perhaps in the same
way as lightning heads for pointed objects because of the greater density
of charge around them.

Eyewitnesses have reported that the circles form to the accompaniment
of a humming noise, like the electric hum from high-tension wires. Land-devil
whirlwinds make a similar noise that researchers attribute to electrostatic
fields resulting from friction within the moving air. The vortices that
make corn circles are probably electrically-charged too, by some means dependent
on their intense spin. The density of airborne particles such as pollen,
dust and salt, serving as charge carriers, may play a role in the build-up
of electric charge, as water droplets do. Unlike fair-weather whirlwinds,
which form from rising currents of air in daylight only, the vortices that
form circles happen at night too; the electric fields could also account
for lights seen near circles in Kent and Wiltshire last summer.

Around midnight on 28 June 1989, a man saw a big orange ball of light
moving downward into a Wiltshire wheat field just in front of a sloping
hill. The witness watched the bottom ‘go flat’ as it reached the ground,
the light disappeared a few seconds later. Next morning there was a 15-metre-wide
ringed circle at that spot. In Kent, late on 10 August, Wilfred Gomez and
a friend spotted a ‘vortex of light’ in a wheat field south of Margate.
It dissipated before they got to the site, but immediate investigation by
moonlight revealed a circle 18 metres in diameter.

These reports of circles with lights have antecedents from countries
other than Britain, among them France, Japan, Australia and the US. Taken
together they support the idea that balls of light of exceptional dimensions
create the circles. One instance, in Japan’s Tamagata Prefecture in 1986,
was accompanied by television interference that indicated radio-frequency
emissions.

In the space of 10 years the study of circles has grown from a small-scale
inquiry into a project with serious scientific potential and a considerable
popular following. Field investigations start in May when the crops are
mature enough to suffer permanent damage when struck by the spinning air,
and work continues until harvest time. Besides marking other types of crop
and vegetation, these vortices leave circular traces in earth, sand, snow
and frost-covered grass, occasionally scouring or blasting hollows.

The circles have great popular appeal. Many amateur circle-spotters
collect extensive and useful data. But the subject has also been invaded
by cranks and publicity-seekers, whose wild guesses about extraterrestrial
origins divert attention from the science of how the circles form.

We expect that other countries suffer similar vortex-phenomena where
topography, air stability and frontal types are similar, but a comparable
rate of circle frequencies demands that the land be crop-covered too. In
Southern England these conditions combine superbly every summer, and render
Wiltshire the most prolific area in the world for the natural production
of these exquisite circles.

* * *

Have you spotted a circle?

CERES, the Circles Effect Research Group, survey circles and gather
reports from all parts of the world. In addition, we seek information about
happenings involving relatively small rotating masses of air (other than
tornadoes) that descend from the skies, especially if they affect buildings,
gardens, automobiles, animals and people, by night or day. We include electromagnetic
phenomena too, for we have gathered some direct evidence and a vast amount
of circumstantial evidence which link the type of vortex that forms circles
and rings to optical and electrical manifestations similar to ball-lightning.

With the aim of assembling into a single archive every bit of information
relevant to the subject, we have set up an international data bank. This
brings together reports and photographs on circles effect and circular blasts
and on related phenomena involving unusual noises (humming, whining, crackling,
etc), electrical effects (interference to radio-communications, television,
vehicle performance), and luminosity (especially low, hovering, spinning,
pulsating and descending lights).

Additional help from enthusiasts who can serve as spotters and local
investigators anywhere in Britain or the rest of the world is welcome. Besides
reporting on circles, we need to monitor potential sites night and day with
the hopes of filming circles as they form, and pinning down the electromagnetic
spinning sys tems which create them.

Readers who can provide data are invited to get in touch with CERES
as are those who feel they could help in the future by acting as spotters
and investigators of crop circles anywhere in England or the rest of the
world.

Terence Meaden, formerly associate professor of physics at Dalhousie
University, Halifax, Canada, has been a ‘vortex watcher’ for 30 years. In
1974 he founded TORRO, the tornado and storm research organisation, in 1975
the Journal of Meteorology, and in 1988 CERES, the circles effect research
group. Contact him at 54 Frome Road, Bradford-on-Avon, Wiltshire BA15 1LD.

Further reading: Circles from the Sky, Terence Meaden, to be published
in July by Artetech. The circles effect and its mysteries, Terence Meaden,
Artetech. See also ‘Vortex breakdown in atmospheric columnar vortices’,
H. J. Lugt, Bulletin of the American Meteorological Society, volume 70,
pages 1526 to 1537, 1989.