Aerial view of a crop formation near Alton Barnes, Wiltshire, England. Crop formations are patterns of flattened plants in crops such as wheat or barley. They started appearing frequently in the mid1980s in southwest England. Their cause is unknown. Many theories exist, ranging from sciencebased physical explanations such as the plasma vortex theory based on the phenomenon of electrohydrodynamics (EHD) to suggestions that they are created by alien intelligences. This formation was photographed a few weeks after its appearance, and shows typical signs of damage as a result of people tramping around it.