A team of Australian scientists believe they’ve uncovered the explanation for one of nature’s most bizarre phenomenon – ball lightning.
Ball lightning, typically the size of a grapefruit, is a rarely seen event that lasts up to 20 seconds.
“Ball lightning has been reported by hundreds of individuals … for centuries and it is a huge mystery,” says CSIRO scientist John Lowke, lead composer 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 possible causes. One recent theory suggests it’s burning silicon that has 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 lots of observations of bola tangkas lightning appearing from a glass window either in a home (or) … in the cockpit of an aircraft,” Lowke says. “If it’s burning silicon, how achieved it can be found in?”
After hitting the floor and lighting the sky, lightning strikes leave behind a trail of charged particles, or ions. In most cases, these positive and negative ions recombine in a divided seconds, says Lowke. Any remaining ions travel down seriously to the ground.
Lowke’s theory, is that many of these ions can accumulate externally of non-conducting surfaces such as a window.
“These ions pile up and produce an electric field which penetrate the glass,” he says.
Lowke says the field gives free electrons internally of the window enough energy to knock off electrons from surrounding air molecules, in addition to release photons, creating a glowing ball.
Recreating it in the lab
“Here is the first paper which provides a mathematical solution explaining the birth or initiation of ball lighting,” says Lowke.
He says the next step is to utilize the idea to reproduce ball lightning in the laboratory. That’ll still prove difficult, because it would require equipment effective at producing 100 million volts.
But a baseball 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 though 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.”
Taking care of of ball lightning that the analysis didn’t tackle is the loud bang that may occur at the conclusion of a display.
“About a third of the sightings end in a hammer,” says Lowke. “[It may be that] the electric field tends to heat the gas and everything will take off getting hotter and hotter and hotter and the bang is due to the expansion of the gas.”
But he says that is just speculation and is very happy to leave that for another study.Read More