Canberra, March 20 : Physicists have been baffled by natural phenomenon known as ball lighting, which are lightning strikes that are sometimes associated with intriguing shimmering balls of light that hover above the ground for minutes at a time before disappearing.
According to a report in ABC Science, scientific theories and experiments have failed to convince physicists what's behind the mysterious natural phenomenon of ball lightning.
"I don't believe there is any satisfactory explanation so far," said Emeritus Professor Bob Crompton of the Australian National University, referring to these small bright lights that appear after a lightning strike.
"The theories don't satisfy me and I don't think they satisfy anyone who looks at the evidence objectively," he added.
Crompton, an expert in atomic and molecular physics and electrical discharges in gases, has been interested in the science behind ball lightning for decades.
He's collected 30-40 Australian sightings over a period of about 10 years, with the help of Australian meteorological services.
According to Crompton, ball lightning is a bright light, anywhere in size from a golf ball to larger than a football.
It hovers above the ground, moving slowly, able to pass through walls, until it vanishes minutes later.
Till now, two main theories have been put forward to explain ball lightning.
One theory, based on the physics of electrical discharges, says that lightning strikes and travels slowly through conductive channels in the ground.
This theory states that a high electrical field is created in the air as the lightning moves through the ground, and ball lightning is formed from electricity discharging in this field.
The other theory, which is purely chemical, says lightning hits a surface containing silica and carbon in the ratio of 1:2.
The extreme heat of the lightning converts these chemicals into carbon dioxide and nanoparticles of silicon, which puff out of the surface in the shape of a ball. This ball shimmers as the silicon oxidises in the air generating heat and light.
According to Crompton, this second theory was given a boost by an experiment carried out by French scientists that recreated silicon nanoparticles in the laboratory using electricity.
While Crompton said that this second theory is the most likely explanation for ball lightning, it doesn't really explain how ball lightning has the ability to get into a house.