Wednesday, February 20, 2013

Nature’s Power Source

In January 1984, the pilots of a Soviet Ilyushin-18 aircraft flying over the Black Sea were astonished and terrified to see a fireball, about four inches in diameter, in front of their airplane.

Then, as the Soviet news agency Tass reported, the fireball “disappeared with a deafening noise, but reemerged several seconds later in the passengers’ lounge, after piercing in an uncanny way through the airtight metal wall. The fireball slowly flew above the heads of the stunned passengers. In the tail section of the airliner, it divided into two glowing crescents, which then joined together again and left the plane almost noiselessly.”

The Russians had witnessed one of nature’s rarest and most mysterious phenomena—ball lightning.
Detailed reports date back many centuries, Diane de Poitiers, mistress of Henry II of France, is said to have been burned by a ball of lightning that chased her around her bedroom on her wedding night in 1557. One year earlier, eight people in England were reported to have been killed by a “fiery, sulfurous globe” that rolled through a door.

Today, ball lightning is no longer a phenomenon of purely natural interest, for scientists are now studying it as a possible new source of energy. In Rotterdam, in the Netherlands, researchers have begun an elaborate experiment that may lead to the production of electricity from artificially created ball lightning.

The leader of the Dutch team, Gerard C. Dijkhuis, has proved that the lightning ball is held together by forces that fuse its atomic particles. If this fusion reaction could be controlled, ball lightning could be used to generate inexpensive electric power.

The first step: produce ball lightning to order. Dijkhuis had heard that sailors often report seeing the phenomenon following short circuits occurring in submarine batteries, and bought from the Dutch Navy an old system of 400 individual batteries.

Dijkhuis installed them in a shed on a dock in Rotterdam, linked them together, and then short circuited the system. Success came in 1985, although the apparatus produced fireballs only four inches in diameter and they lasted no more than a second. In subsequent experiments the scientists hope to sustain the ball indefinitely and create a continuing source of power.

One of the greatest problems, the Dutch team faces, is that no one can offer an easy explanation for ball lightning. Some researchers have even suggested that it is an optical illusion, no more than an image left on the retina of the eye following a conventional lightning flash. But the many reports of seeing it inside buildings, where no conventional lightning was visible, argue against this theory.

Two British investigators, Mark Stenhoff and Dr. E.R. Wooding, have made a list of the characteristics of ball lightning, based on more than 50 reports. Their analysis confirmed many properties of ball lightning that scientists had previously only suspected.

For example, they found that in 69 percent of the cases ball lightning is seen out-of-doors, although it can also occur in enclosed spaces, such as the room of a house or, as the Ilyushin-18 passengers discovered, in an airplane cabin. In 89 percent of the cases, the phenomenon appears during a thunderstorm. But, intriguingly, the researchers found that about a third of the witnesses had not seen it come from a conventional lightning flash.

A ball itself, Stenhoff and Wooding concluded, is about 10 inches in diameter, lasts about five seconds, and is as bright as a 40 watt light bulb. 

Occasionally, it seems to leave a pungent smell. In about a quarter of the cases the ball lightning caused damage; a broken window, for example, or scorched grass. More than half of the people who took part in the survey said that the ball seemed to explode as it disintegrated.

But ball lightning remains a mystery, and a tantalising one on that. Some scientists see it as far more than a possible source of energy. Ball lightning, they contend, is plasma, rare on earth but common in the sun and the stars beyond our atmosphere. Close study of its properties may offer a key to a greater understanding of the universe itself.

However, such projects are likely to mean little to those who happen to encounter the phenomenon. One lady in Florida did not pause to theorise when a sphere of lightning “the size of basketball” rolled into her house. Instead, she hit it firmly with her flyswatter.

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