Unexplained Mystery #2: Crop Circles

In the 1960s, the earliest crop circles were primitive circular patterns of flattened crops, often created in mysterious circumstances overnight.

During the last 20 years, though, crop circles have evolved to be far more complex. They now form geometric shapes like the DNA double helix, or fractals like the nautilus shell. Whoever creates these mysterious patterns has become rapidly more advanced in just a period of a few decades. A bit like man.

The first crop circle, recorded in 1966, was discovered by an Australian sugar cane farmer who claimed to see a saucer-shaped spaceship rise up from a swamp before flying away. This was around the time that flying saucers became really popular in sci-fi literature, and ever since, our obsession with alien visitation has fuelled the frenzy.

As unexplained mysteries go, this one has been debunked numerous times. There is ample evidence to show how crop circles are a man-made hoax.

In 1991, two men from Southampton, England, admitted they had been creating hoax crop circles for 15 years. They could make intricate patterns using planks, rope, hats and wire - and could create a 40-foot circle in 15 minutes. The only reason they came clean was because one of the men was running up considerable mileage on his car and had to convince his wife he wasn't having an affair. He still publicly demonstrates the art today.

Further studies have dismissed claims that alien saucers have been leaving excessive nitrate deposits at crop circle locations. The trace deposits are explained by the nitrate-based fertilizers used by farmers to grow their crops.

Other paranormal fans claim that there is a mysterious energy left behind within crop circles and people go there to mentally make contact with an extra-terrestrial energy. What could create such a widespread psychological effect?

Science refers to this as The Placebo Effect - where the mind can produce powerful effects on the body simply because the person expects it to. Indeed, the mind is so powerful (and science fully accepts this) that it can sometimesheal the body just as well as medicine when that medicine is replaced by a sugar pill, even when the patient knows it's a fake.