Ball lightning has fascinated scientists for decades, due to the circumstances of its appearance, the inconsistent behavior it exhibits and its tendency to just move around randomly before going out with a bang in a most literal fashion.
A new study from a team of Australian scientists attribute a somewhat unexpected cause to the unexplained phenomenon: leftover ions.
John Lowke and colleagues at the CSIRO
and the Australian National University started with reports about ball lightning forming near windows of houses and airplanes.
"There are many observations of ball lightning appearing from a glass window either in a house (or) in the cockpit of an aircraft," Lowke said.
According to the findings, ball lightning can be explained by a process whereby, upon striking the ground, or just cutting through the atmosphere, lightning leaves behind a trail of charged particles or ions.
Normally, positive and negative ions recombine instantly, with remaining ones being drawn towards and into the ground. Some could accumulate outside of non-conducting surfaces though, like a window. It is on these rare occasions that ball lightning appears, the team believes.
"These ions pile up and produce an electrical field which penetrate the glass," Mr. Lowke said. "This is the first paper which gives a mathematical solution explaining the birth or initiation of ball lighting."
The shape of ball lighting is explained by the assumption that the spherical field gives the free electrons on the inside of the window enough energy to repel the ones in the surrounding air, all the while releasing photons.
The explanation also seems to discredit a previous theory saying that “ball lightning is created by slowly burning particles of silicon formed in a lightning strike,” since one occasion happened when there was no thunderstorm at all.
"After flying for about 15 minutes, there developed on the randome (radar cover) two horns of Saint Elmo's fire. It looked as if the airplane now had bull's horns...they were glowing with the blue of electricity," recounts Former US Air Force lieutenant Don Smith.
Previous presumed causes for ball lightning include dark matter, antimatter, radiation from thunderclouds, oxidising aerosols, nuclear energy and even black holes.