Great question and only something that relatively recently has been given a satisfactory answer not based on conjecture, thanks to one Dr. Tonya Coffey of Appalachian State University and some of her physics students. Dr. Coffey decided to do a study on this very phenomenon after being slightly unsatisfied with MythBusters’ explanation of the phenomenon. Thus, she did a research project and wrote a paper with her results, later published in the American Journal of Physics, June 2008.