© Storm Wolf / FlickrExplanations for how ball lightning is formed are even more diverse than its physical characteristics. Just a sampling of the theories out there suggest the ball is a cloud of hot silicon particles, a natural nuclear reaction, a lightning-induced epileptic hallucination, a miniature black hole, an aggregate of cellulose and other natural polymers, and a microwave-filled bubble of plasma.
Every so often, given the proper conditions, a small and roughly spherical piece of the atmosphere around us will briefly catch fire. As they are best viewed late into the night and have no obvious natural explanation, it's perhaps no wonder they've inspired a rich mythology.
Names for balls of fire include
ignis fatuus, will-o'-the-wisp, ghost lights, and ball lightning. They've been said to hover above graves, dance along the banks of rivers, signal the imminent arrival of an earthquake, and stalk the aisles of airplanes. Even today, we don't have a crystal-clear understanding of how they form and do what they do. Which doesn't mean scientists have, well, dropped the ball. Chinese scientist H.-C. Wu recently offered a compelling new
explanation in
Scientific Reports.
Some fireballs appear to be the products of living organisms. The decay of organic matter, for example, in marshes and other wetlands (
or even a mass grave in a Polish forest) leads to the release of methane and phosphorus-containing gases such as phosphine, which can spontaneously catch fire after encountering oxygen in the atmosphere, producing a flickering light suspended midair. Some, on the other hand, are electrical in origin, sparking
within the ground during an earthquake as stressed rocks release a stream of electrons to the surface where, interacting with air, they produce flashes of light. Still others form in the atmosphere, usually during thunderstorms, and go by the name of "ball lightning."
Comment: See also: The extraordinary case of the Guevedoces