A team of Australian scientists believe they’ve uncovered the cause of among nature’s most bizarre phenomenon – ball lightning.
Ball lightning, typically the size of a grapefruit, is just a rarely seen event that lasts as much as 20 seconds.
“Ball lightning has been reported by hundreds of people … for centuries and it is a mystery,” says CSIRO scientist John Lowke, lead writer of a fresh study published in the Journal of Geophysical Research Atmospheres.
Previous theories have suggested microwave radiation, oxidising aerosols, nuclear energy, dark matter, antimatter, and even black holes as you can causes. One recent theory suggests it is burning silicon that’s been vapourised by way of a lightning strike.
To unravel the mystery Lowke and colleagues at the CSIRO and the Australian National University turned their attention to reports of ball lightning forming near windows.
“There are numerous observations of ball lightning appearing from the glass window either in a residence (or) … in the cockpit of an aircraft,” Lowke says. “If it’s burning silicon, how did it can be found in?”
After hitting the bottom and lighting the sky, lightning strikes leave behind a trail of charged particles, or ions. Generally, these positive and negative ions recombine in a split seconds, says Lowke. Any remaining ions travel down to the ground.
Lowke’s theory, is that a few of these ions can accumulate externally of non-conducting surfaces such as a window.
“These ions pile up and produce a power field which penetrate the glass,” he says.
Lowke says the field gives free electrons inside of the window enough energy to knock off electrons from surrounding air molecules, in addition to release photons, creating a great ball.
Recreating it in the lab
“Here is the first paper which gives a mathematical solution explaining the birth or initiation of ball lighting,” says Lowke.
He says the next phase is to use the theory to reproduce ball lightning in the laboratory. That could still prove difficult, since it would tangkasnet require equipment capable of producing 100 million volts.
But a ball lightning event seen by way of a former US Air Force pilot suggests another approach.
While flying a C-133A cargo plane from California to Hawaii in the mid 1960s, former Lietutenant Don Smith saw two horns of Saint Elmo’s fire appear on the plane’s randome (radar cover), followed by ball lightning inside the cockpit.
“It looked as if the airplane had bull’s horns…they were glowing with the blue of electricity,” says Lowke. “[It] was driven by ions from the aircraft radar operated at maximum power during a thick fog.”
One aspect of ball lightning that the analysis didn’t tackle is the loud bang that can occur by the end of a display.
“About a third of the sightings result in a return,” says Lowke. “[It may be that] the electric field has a tendency to heat the gas and everything will take off getting hotter and hotter and hotter and the bang is caused by the expansion of the gas.”
But he says that’s just speculation and is happy to leave that for another study.