SEED Science


Lightning: The Sky Out of Balance
Ball Lightning

Ball lightning.
Photo courtesy of Ron Shawley.

Ball lightning, seen in the upper right portion of this photo, is a very rare phenomenon. Photos of ball lightning are scarce because the glowing orb is unpredictable and only lasts for seconds.

 

Think of a brightly glowing ball, between the size of an orange and a basketball. This ball zips just above the ground, sometimes straight into the wind. It slips through keyholes, reemerging as a ball on the other side. It can burn small holes in windows, walls, and even the hull of an aircraft. It is attracted to living beings, humans included, and often appears to “chase” them. If the ball lightning draws within a few meters of someone, it creates a sensation of tingling or mild shock. Then, in less than a minute, the glowing sphere disappears—sometimes with an explosive boom and sometimes in eerie silence. Perhaps the best way to define the mysterious phenomenon of ball lightning is to describe one of the many reported encounters:

On January 13, 1984, a 120-passenger Russian aircraft took off from the city of Sochi on the Black Sea coast. The overhead sky was calm, but a thunderstorm raged some 40 km (25 mi) away. At 1,200 m (about 4,000 ft) in altitude, the flight turned from routine to shocking.

A glowing ball of light the size of a grapefruit appeared near the nose of the aircraft, which had a cruising speed of 650 km/h (400 mph). The pilots watched in astonishment as it disappeared with a loud bang. The globe reappeared suddenly in the passenger section of the airplane. It flew over peoples’ heads and chased a frightened flight attendant down the aisle. At the tail of the craft, the ball split into two crescents, rejoined, and then silently exited the aircraft. Mechanics later found two small holes in the airplane’s thick, metal hull—an entrance hole at the nose and an exit hole at the tail. No one was hurt, but ball lightning has been known to injure and kill.

Dozens of people aboard the Russian aircraft witnessed this bizarre event. They aren’t alone. Other people have reported seeing a mysterious glowing ball that appears, behaves strangely, and disappears in about a minute. There are too many of these reports, dating back to ancient Greece, to doubt that ball lightning exists. Yet no one knows exactly what it is and how it forms.

The ongoing quest of scientists is to marry all the observations with the laws of physics in a provable scientific theory. Witnesses have reported that the balls range from pea- to bus-sized, often appear after a lightning strike, are bright enough to see in daylight, vary in color, and can travel against the wind. They sometimes float parallel to the ground and other times bounce along the ground like a beach ball. They can pass through keyholes and under doors.

Russian physicist Pyotr Kapitsa believes ball lightning is an electrical discharge caused by ultrahigh frequency (UHF) waves between the ground and a cloud. New Zealand scientists John Abrahamson and James Dinniss theorize that it consists of “fluffy balls of burning silicon created by ordinary fork lightning striking the Earth.” Hundreds of other theories point a scientific finger at atmospheric masers (low-energy versions of lasers), standing electromagnetic waves, optical illusions, antimatter particles, plasma balls, and so on. But so far, no theory can explain all the observed behavior of ball lightning.

Also poorly understood are recently discovered forms of lightning given fanciful names.


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