Crop Circles

A field of wheat, around three hundred thousand individual stalks, each swaying in the wind. Click the ground and a pattern is pressed into it: the stalks inside the shape bend flat in a tangential swirl, sweeping outward from the centre as a wave, the way a real formation lays down. Nothing on the ground is painted on. Every flattened stalk is an individual blade, rotated about a horizontal axis toward its lay direction.

Choose from fifteen real formations, rotate and resize them, or upload your own design as a mask. It is a sandbox for the craft of the crop circle: the geometry itself, and the way standing wheat becomes a drawing when it is laid over.

Crop circles sit squarely on this site's territory: a phenomenon that is unambiguously real as an artefact (you can stand in one, photograph it, measure it) and unresolved as to cause. Thousands have appeared in fields since the late 1970s, concentrated in the chalk downland of southern England, growing from simple circles into geometry of startling complexity.

There are two accounts of how they are made. Researchers who catalogue formations count more than ten thousand worldwide and say only a few hundred have ever been claimed by anyone. They describe formations appearing in a single short night, in standing crop, with no tracks leading in or out and hundreds of elements laid out with near-mathematical precision. They also point to the plants. In papers in Physiologia Plantarum the biophysicist W. C. Levengood reported stem nodes swollen and burst open from the inside, which he attributed to brief intense heating, and reported altered growth in seeds taken from formed crop; Eltjo Haselhoff fitted node data from one Dutch formation to a single point source of energy above the field. Supporters say no hoaxer has reproduced these plant changes.

The other is the mainstream account: people make them. In 1991 Doug Bower and Dave Chorley said they had been flattening circles since 1978 with a plank and a loop of rope. Since then circle makers such as Rob Irving and John Lundberg have described the craft openly, small teams have made complex designs at night, and most makers never sign their work. Sceptics, including Joe Nickell in the Skeptical Inquirer, argue that the plant studies do not hold up on sampling and controls. This page does not rule between them. Open the interactive, where the About panel sets out the anomaly case in its own voice, and find the sources for both sides below. (We keep the honest gaps in plain sight too: see Caveats for where the record is still unsettled.)

The field is one instanced mesh: the geometry of a single stalk drawn about three hundred thousand times, each copy given its own position, height, phase and lay state on the GPU. The wind sway, the per-stalk yaw and the flattening all happen in a vertex shader, so the whole field animates in real time.

When you stamp, the pattern is read from a 512-pixel mask. For every stalk under the shape, the simulator sets a lay angle (a clockwise tangential swirl, the signature of a real lay, plus jitter), a flatten amount from how solidly that point is covered, and a start time, so the fall ripples outward from the centre rather than snapping flat at once. Lit from a low sun, the laid stalks catch a sheen along their lay direction, which is what makes a formation read from above.

It is a real-time visualisation built for the look and the geometry, not a physical model of how a real lay forms.

The fifteen presets are all real, verified formations, recreated procedurally rather than traced from anyone’s artwork. Each is captioned with month and year. They range from the simple classic ring to the Milk Hill galaxy and the Barbury Castle "Pi" formation.

• Real formations. Each preset corresponds to a real crop circle with a location and a date. They are regenerated in code rather than copied from existing vectors, because a pattern may be an artist’s work even though the formation itself was a public event.
• Upload your own. Any image can be used as a mask (black on white, or with transparency) to stamp your own design. An invert toggle handles images whose light and dark are reversed.
• Month and year. Captions give the month and year only, not the day, by the same convention the simulator uses throughout.

Keeping what is documented apart from what is claimed:

In one line: the formations are real objects; the mainstream account is that people make them, and makers have shown how; anomaly researchers point to a few hundred claimed hoaxes against more than 10,000 on record and to published plant-node findings, which critics dispute on sampling and controls; no non-human mechanism has been established.

• Levengood, W. C. (1994). Anatomical anomalies in crop formation plants. Physiologia Plantarum, 92(2), 356–363.
• Levengood, W. C., & Talbott, N. P. (1999). Dispersion of energies in worldwide crop formations. Physiologia Plantarum, 105(4), 615–624.
• Haselhoff, E. H. (2001). Opinions and comments on Levengood & Talbott (1999). Physiologia Plantarum, 111(1), 123–125. The point-source electromagnetic model.
• Bower, D., & Chorley, D. (1991). The two self-confessed hoaxers who claimed the early English formations, flattening crop with a plank and rope; widely reported (e.g. Today, September 1991).
• Crop circle. Wikipedia. A mainstream overview of the phenomenon, its hoaxing history and the human-made consensus: en.wikipedia.org/wiki/Crop_circle.
• Nickell, J. (various). Sceptical analyses of the crop-circle phenomenon, Skeptical Inquirer. The counter-case to the anomaly claims.
• Irving, R., & Lundberg, J. (2006). The Field Guide: The Art, History & Philosophy of Crop Circle Making. An account of the craft from inside it.

A list of the real formations behind the presets ships with the simulator (famous-formations-reference).