|
|
|
|
|||||||||||||||||||||||
|
Instances of "ball lightning", or at least phenomena that might well be construed as ball lightning, have been observed for hundreds of years. It is indeed likely that many historical (or contemporary) accounts relating to magic or UFOs may well be related to this natural phenomenon. Despite these many years of precedent, however, it is only over the past few decades that scientists have begun to take ball lightning seriously. Information about ball lightning (as no theory has been confirmed as the 'definitive answer') comes mostly from eye-witness reports. Unfortunately, these sightings vary wildly in content, perhaps indicating that there are different kinds of ball lightning stalking the people of Earth. In May of 1949, several farm labourers were gathering the asparagus harvest in Rushford, England. Peggy and Delia Filby were among those who took refuge from a rainstorm by sheltering themselves within a tarpaulin covered trailer. During the height of the thunderstorm, a brilliant flash rocked the area indicating a heavy lightning strike. Delia and others then saw what they described as a "football-sized, softly glowing orange-red ball of light". It gave off neither sparks nor rays, and did not pulse as it bounced across the field, towards the frightened observers. Within a few seconds, however, the ball disappeared soundlessly. The workers experienced something like an electric shock as it did so. In 1967, M. Dmitriev, a Russian chemist, was camping on the banks of the Onegaw river. Following an intense lightning flash, a "ball of fire" appeared about 30 cm over the surface of the water, unaffected by the intense winds. The ball crackled and hissed as it flew past his head and into a group of nearby trees. The sphere bounced from tree to tree "like a billiard ball", emitting a trail of blue-grey smoke. One of the most (in)famous ball lightning sightings comes from Roger Jennison, professor of Electronics at the University of Kent. In March of 1963, while caught in a storm en route from New York to Washington, his plane was enveloped by a bright and audible electrical discharge. Some seconds later, a glowing sphere emerged from the pilot's cabin and passed through the central aisle of the aeroplane, from one end to the other. The ball floated at about 75 cm above the floor, and moved at approximately 1.5 metres per second (relative to the aircraft). It gave off no discernible heat, and was an opaque, blue-white colour. From these accounts and others, scientists have come to understand that ball lightning typically occurs shortly after 'normal lightning', although it has been known to arise several days after such a lightning strike. It appears able to pass through glass and solid objects, sometimes causing damage in the process, and only rarely emits heat. Sometimes a hissing or crackling sound can be heard, other times it is perfectly silent. Ball Lightning origin theories from AA&ES Magazine. "A simple answer to the phenomenon doesn't appear to be forthcoming and tentative explanations rely heavily on theoretical physics. One of the current favourites concerns electromagnetic plasmoid models: the greatest problem for the theorist is explaining how sufficient energy be contained within such a small space without it being emitted steadily and continuously, but sometimes suddenly. Dr. Geoff Endean (School of Engineering and Computer Science, University of Durham) has suggested that the energy containment problem can be circumvented since a very rapidly rotating electric field can exist in a plasma without a magnetic field with no apparent limit to the electrical field strength - heady stuff indeed. Furthermore, it has also been suggested that ball lightning may occur quite frequently but the electromagnetism associated with it is not strong enough to render it visible to the eye on the vast majority of occasions. Another rather more radical theory invokes anti-matter as the root cause. The idea is that it is drawn down from the upper atmosphere by the circulating air currents in thunderstorms where it interacts with ordinary terrestrial matter, whereupon both are annihilated with a tremendous release of energy that makes the glowing ball. With the lack of solid scientific evidence or theory, however, it is almost inevitable that there are also those on the fringe who attribute an extra-terrestrial origin to the light phenomenon." Specific Information on Ball Lightning as culled from Earth Lights.
| |||||||||||||||||||||||||
| ||||||||||||||||||||||||||