Ball lightning is still a mystery. One thing it certainly is not is evidence of paranormal activity. But what it is is not as certain.
Ball lightning is a rarely observed event. Fewer than five percent of people will see it even once in their lifetime. Those who do see it are among the privileged few, unless it kills them, which happens even more rarely. Photographs are nearly non-existent, given the low likelihood of an observer having a camera at the time and the briefness of the encounter.
For one species of ball lightning – there may be more than one – the descriptions are mostly very similar, indicating the phenomenon is probably real. They describe an object, mostly in the ping-pong ball to basketball size range, usually spherical, floating, hovering or moving horizontally, glowing, often with internal structure.
Georg Richmann of St. Petersburg, Russia was trying to repeat an experiment done by Benjamin Franklin the year before, involving flying a kite in a thunderstorm. It worked out alright for Franklin in 1752, but not the following year for Richmann. A lightning ball collided with his head and discharged through his body, killing him, injuring his assistant and damaging surrounding structures.
Other reports have happier outcomes. People describe the experience as enchanting or amazing. For some there’s a sense of calm and often there are mystical overtones. Naturally, the balls have been used as omens and portents. Their rarity, beauty and potential danger make them special.
Any theory of ball lightning must explain several things, such as why they float and why they persist for so long, typically a few seconds. By comparison, real lightning is over in a flash.
Once past the sprites and pixies, gods and demons, there are a few scientific hypotheses. The two main categories are hot plasma and warm dust, both kicked up by a bolt of lightning. The hot plasma would account for the glow, but would be hotter than most accounts. Also, a bubble of hot plasma would rise quickly out of sight, not hover. The warm dust contains tiny mineral particles which burn slowly when exposed to oxygen, while there’s enough static charge for internal sparking as well as hovering.
Ball lighting has been produced in the laboratory using the dust hypothesis, but the natural phenomenon is still a mystery.