The first scientific theory that explains the creation of the Crop Circle is Plasma Vortex Theory. A physicist and meteorologist Terence Meaden hypothesized that a whirlwind or tornado can produce a plasma vortex which bents the crops, forming a Crop Circles. The whirlwind theory later was redeveloped again by Dr. William Levengood (Mark). Levengood explains that the crops undergo biochemical and biophysical changes as they are exposed to burning from the microwave heating (Howe). This theory explains the different characteristics of crop from the crop in man made Crop Circle. The crop samples that Levengood examined has special characteristic, exploded nodes in the stem of the crop (Mark). The swollen and reoriented growths of nodes prevent the crops from being broken or die, and instead, let the crop grow even after they are bent ninety degrees (Howe).