Ball lightnings so freaky its often mistaken for a UFO. What in fact is it?
A. Nobody knows, says University of Florida electrical engineer Martin A. Uman in “All About Lightning.” The phenomenon is still so poorly understood it’s not clear if the energy source for these luminous “floating” colored spheres about the size of an orange or grapefruit is internal (gas behaving bizarrely?) or comes from some outside source (nearby thundercloud?). Though 5-10 percent of people have witnessed it, ball lightning has never been captured on film, adding to its mystery. One vivid account came from an Iowan after a violent thunderstorm: “I heard a heavy rushing sound, looked about and saw a yellowish-white fireball about the size of a wash tub bouncing down the dirt road, faster than one could run. It went about a city block, hit a small shed, which exploded, killing a horse inside.” Red or yellow balls are common, lasting a second or so, moving horizontally or hovering in midair, says Uman. At times they spin or bounce along the ground. Balls may enter houses through chi
