Anyone know what they are doing to cause such a huge arc? Anyone saw one of these in real life? They look amazing and crazy dangerous!
http://www.killsometime.com/Video/video.asp?video=Electric-Arc

My guess is that the arc ionized the air. Ionized air has little resistance. As it was heated, this air rose, carrying the arc with it. When the path became too long, the arc failed. (This could only happen were it a very still day).