melted stone from Waidhofen/Thaya TV-Report in "Österreich Bild" ORF 28.8.2007
reference: Elisabeth Widensky
Ball lightning is an atmospheric phenomenon, the physical nature of which is still controversial. The term refers to reports of a luminous object which varies in size from golf ball to several meters in diameter. It is sometimes associated with thunderstorms, but unlike lightning flashes arcing between two points, which last a small fraction of a second, ball lightning reportedly lasts many seconds. There have been some reports of production of a similar phenomenon in the laboratory, but some question whether it is the same phenomenon.
Reports Despite over 10,000 reported sightings of the phenomenon, ball lightning has often been regarded as nothing more than a myth, fantasy, or hoax. Reports of the phenomenon were dismissed due to lack of physical evidence, and were often regarded the same way as UFO sightings.
A 1960 paper reported that 5% of the US population reported having witnessed ball lightning. Another study analyzed reports of 10,000 cases.
Ball lightning is photographed very rarely, and details of witness accounts can vary widely. Many of the properties observed in ball lightning accounts conflict with each other, and it is very possible that several different phenomena are being incorrectly grouped together. It is also possible that some photos are fakes.
The discharges reportedly appear during thunderstorms, sometimes issuing from a lightning flash, but large numbers of encounters reportedly occur during good weather with no storms within hundreds of miles.
A report from an area of central Africa having a very high incidence of lightning said that ball lightning used to appear from a certain hill just before the onset of the rainy season.(The report also exhibits a reluctance to report such phenomena typical of many people).
Ball lightning reportedly tends to rotate or spin and can possess odd trajectories such as veering off at an angle or rocking from side to side like a leaf falling. Fireballs can also move with or against the wind. Other motions include a tendency to float (or hover) in the air and take on a ball-like appearance. Its shape has been described as spherical, ovoid, teardrop, or rod-like with one dimension being much larger than the others. Many are red to yellow in colour, sometimes transparent, and some contain radial filaments or sparks. Other colours, such as blue or white occur as well.
Sometimes the discharge is described as being attracted to a certain object, and sometimes as moving randomly. After several seconds the discharge reportedly leaves, disperses, is absorbed into something, or, rarely, vanishes in an explosion. Some accounts have the balls passing freely through wood or glass or metal, while other accounts report circular holes in the wood or glass or metal. Some report explosions when the balls contact electrical wiring or the vaporisation of water when the balls enter water. Some accounts say the balls are lethal, killing on contact, while other accounts say the opposite.
A 19th Century depiction of ball lightningTesla reportedly could consistently make ball lightning in his Colorado lab, with one account saying that he was able to temporarily contain the balls in wooden boxes.
Pilots in World War II described an unusual phenomenon for which ball lightning has been suggested as an explanation. The pilots saw small balls of light "escorting" bombers, flying alongside their wingtips. Pilots of the time referred to the phenomenon as "foo fighters," initially believing that the lights were from enemy planes. However there are other theories as to the identity of the foo fighters.
Submariners in WWII gave the most frequent and consistent accounts of small ball lightning in the confined submarine atmosphere. There are repeated accounts of inadvertent production of floating explosive balls when the battery banks were switched in/out, especially if mis-switched or when the highly inductive electrical motors were mis-connected or disconnected. An attempt later to duplicate those balls with a surplus submarine battery resulted in several failures and an explosion.
Volcanos and the atmosphere and earth around them have been known to produce ball lightning and other luminous effects, with or without electrical storms. These accounts vary greatly.
Other accounts place ball lightning as appearing over a kitchen stove or wandering down the aisle of an airliner. One report described ball lightning following and engulfing a car, causing the electrical supply to overload and fail. In 1773, two clergy men recalled that they saw a ball of light drop down in their fireplace. Seconds later, it exploded.
Some researchers suggest that ball lightning has a more diverse range of properties than previously thought (e.g. Singer, 1971). Japanese investigators (e.g. Ofuruton et al) report that Japanese ball lightning can occur in fine weather and be unconnected with lightning. The diameter is said to be typically 20–30 cm but sometimes even larger up to a few meters. Ball lightning can split and recombine and can exhibit large mechanical energy like carving trenches (e.g. Fitzgerald 1978) and holes into the ground