Some conclusions: 1. Guys like Doug and Dave with planks and ropes are only moderately successful in reproducing crop circles, but certainly not the more complex circles. 2. BLT Research claims that even if identically reproduced as seen by air, there are structural changes in stems that make the plank and rope circles different from the supposed "real" ones. ...Such differences include: a. circles made by planks and ropes break stems. ...b. the "real" circles have unbroken stems with lengthened nodes, and blown out nodes with small holes. 3. BLT Research concludes that the real crop circles have been constructed with an unknown electromagnetic energy having a heat component that somehow accounts for lengthened and blown out stems.
http://www.bltresearch.com/plantab.php http://www.bltresearch.com/plantab.php