Ball lightning

Ball lightning is an unexplained and potentially dangerous atmospheric electrical phenomenon. The term refers to reports of luminous, spherical objects that vary from pea-sized to several meters in diameter. Though usually associated with thunderstorms, the phenomenon lasts considerably longer than the split-second flash of a lightning bolt. Two reports from the nineteenth century claim that the ball eventually explodes, leaving behind an odor of sulfur. Until the 1960s, most scientists treated reports of ball lightning skeptically, despite numerous accounts from around the world. Laboratory experiments can produce effects that are visually similar to reports of ball lightning, but how these relate to the natural phenomenon remains unclear. Scientists have proposed many hypotheses about ball lightning over the centuries. Scientific data on natural ball-lightning remains scarce, owing to its infrequency and unpredictability. The presumption of its existence depends on reported public sightings, which have produced somewhat inconsistent findings. Owing to inconsistencies and to the lack of reliable data, the true nature of ball lightning remains unknown. The first ever optical spectrum of what appears to have been a ball-lightning event was published in January 2014, and included a video at high frame-rate. It has been suggested that ball lightning could be the source of the legends that describe luminous balls, such as the mythological Anchimayen from Argentinean and Chilean Mapuche culture. In a 1960 study, 5% of the population of the Earth reported having witnessed ball lightning. Another study analyzed reports of 10,000 cases. One early account was reported during the Great Thunderstorm at a church in Widecombe-in-the-Moor, Devon, in England, on 21 October 1638. Four people died and approximately 60 were injured when, during a severe storm, an 8-foot (2.4 m) ball of fire was described as striking and entering the church, nearly destroying it. Large stones from the church walls were hurled into the ground and through large wooden beams. The ball of fire allegedly smashed the pews and many windows, and filled the church with a foul sulphurous odour and dark, thick smoke. The ball of fire reportedly divided into two segments, one exiting through a window by smashing it open, the other disappearing somewhere inside the church. The explanation at the time, because of the fire and sulphur smell, was that the ball of fire was 'the devil' or the 'flames of hell'. Later, some blamed the entire incident on two people who had been playing cards in the pew during the sermon, thereby incurring God's wrath. In December 1726 a number of British newspapers printed an extract of a letter from John Howell of the sloop Catherine and Mary: