No, it's not just a spell you can cast in your favourite fantasy-themed role-playing game. The term "ball lightning" is used to describe a rare atmospheric phenomenon that, through means not entirely known to science, resembles a small, glowing sphere of, well, lightning. Despite being witnessed throughout history, it's only now that me might have hit on a solid explanation of how such an effect is created.
Late last week CSIRO announced that, in conjunction with the Australian National University, it had come up with its own mathematical proof, published in the Journal of Geophysical Research Atmospheres, describing how ball lightning is formed. It won't know how accurate this proof is until lab experiments are performed, but going by the press release, CSIRO seems confident it might have cracked the enigma.
According to its research, the phenomenon is the result of residual ions from regular lightning strikes collecting on non-conductive surfaces, such as windows. When enough build up (and under the right conditions) the ions can discharge to form a "ball" of lightning.
But the mathematical recipe, as it were, is just the first step, as CSIRO's John Lowke explains:
"A crucial proof of any theory of ball lightning would be if the theory could be used to make ball lightning. This is the first paper which gives a mathematical solution explaining the birth or initiation of ball lighting," says Lowke.
Apparently, scientists will need to generate an electric field in the million-volt range, which isn't exactly an easy thing to do. Until that happens, we won't have definitive evidence that CSIRO/ANU's proof is on the money.