Unfortunately its seems that most of the crop circles are man made by a group that calls themselves the circle makers.
This video here shows a team making one from start to finish in just a few hours.
Matthew Williams has been arrested and charged for making numerous crop circles and in a world exclusive names all the crop circles that were made by
himself.
1 in a series of 5 (you can just chain watch them on youtube)
Now this may not account for 100% of crop circles but it definitely shows even very complex geometric patterns can be made by men in very short
periods of time. Now I know I'm going to get people posting in here saying BS before they even watch the videos ... but watch them first then
comment.
NATIONAL GEOGRAPHIC TV DOCO
In August 2004, TV channel National Geographic asked experienced crop circles makers John Lundberg, Rod Dickinson and Wil Russell, for a daylight demo
in Wiltshire.
The demonstration was excellent: the design they chose was quite difficult: a 200 ft diagonal square spiral. Intricate squares are easy to do, one
round spiral is easy to do, but a square spiral had never been done before and the risk of failure is high as just one error ruins the entire
formation.
Above: The diagrams they used to create the formation.
Above: Circlemakers Rod Dickinson and John Lundberg (left) with Wessex Sceptics Dr Robin Allen and Chris Nash who were also contributing to the
documentary.
The CircleMakers have a web page about this demo including their original pictures of the formation at:
www.circlemakers.org/Img/nat_geo_stomper.jpg
The three took 5 hours to achieve the formation. This might appear "long" but it is certainly not too much: it is much shorter than a night. Also,
it could have been even shorter: the team had to make lots of breaks for National Geographics' filming.
www.youtube.com...
Third vid in a series of 5 chain watch em on youtube