Ball lightning is a rare and unexplained phenomenon described as luminescent spherical objects that vary from pea-sized to several meters (yards) in diameter. Though usually associated with thunderstorms, the observed phenomenon is reported to last considerably longer than the split-second flash of a lightning bolt and is distinct from St. Elmo's fire and will-o'-the-wisp.
Some 20th-century reports describe balls that eventually explode and leave behind an odor of sulfur. Descriptions of ball lightning appear in a variety of accounts over the centuries and have received attention from scientists. An 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. Nevertheless, scientific data on ball lightning remain scarce. Although laboratory experiments have produced effects that are visually similar to reports of ball lightning, how these relate to the phenomenon remains unclear.
Characteristics Descriptions of ball lightning vary widely. It has been described as moving up and down, sideways or in unpredictable trajectories, hovering and moving with or against the wind; attracted to, unaffected by, or repelled from buildings, people, cars and other objects. Some accounts describe it as moving through solid masses of wood or metal without effect, while others describe it as destructive and melting or burning those substances. Its appearance has also been linked to power lines, altitudes of and higher, and during thunderstorms and calm weather. Ball lightning has been described as transparent, translucent, multicolored, evenly lit, radiating flames, filaments or sparks, with shapes that vary between spheres, ovals, tear-drops, rods, or disks.Barry, James Dale: Ball Lightning and Bead Lightning: Extreme Forms of Atmospheric Electricity, , 1980, Plenum Press (p. 35)
Although they are separate and distinct phenomena,Barry, J.D. (1980a) Ball Lightning and Bead Lightning: Extreme Forms of Atmospheric Electricity. 8–9. New York and London: Plenum Press. ball lightning is often erroneously identified as St. Elmo's fire.
The balls have been reported to disperse in many different ways, such as suddenly vanishing, gradually dissipating, being absorbed into an object, "popping", exploding loudly, or even exploding with force, which is sometimes reported as damaging. Accounts also vary on their alleged danger to humans, from lethal to harmless.
A review of the available literature published in 1972 identified the properties of a "typical" ball lightning, whilst cautioning against overreliance on eye-witness accounts: They frequently appear almost simultaneously with cloud-to-ground lightning discharge They are generally spherical or pear-shaped with fuzzy edges Their diameters range from , most commonly Their brightness corresponds to roughly that of a domestic lamp, so they can be seen clearly in daylight A wide range of colors has been observed, with red, orange, and yellow being the most common The lifetime of each event is from one second to over a minute with the brightness remaining fairly constant during that time They tend to move at a few meters per second, most often in a horizontal direction, but may also move vertically, remain stationary, or wander erratically Many are described as having rotational motion It is rare that observers report the sensation of heat, although in some cases the disappearance of the ball is accompanied by the liberation of heat Some display an affinity for metal objects and may move along conductors such as wires, metal fences, or railroad tracks Some appear within buildings passing through closed doors and windows Some have appeared within metal aircraft and have entered and left without causing damage The disappearance of a ball is generally rapid and may be either silent or explosive Odors resembling ozone, burning sulphur, or nitrogen oxides are often reported
Historical accounts Ball lightning is a possible source of legends that describe luminous balls, such as the mythological Anchimayen from Argentinean and Chilean Mapuche culture.
According to a statistical investigation carried out in 1960, of 1,962 Oak Ridge National Laboratory monthly role personnel, and of all 15,923 Union Carbide Nuclear Company personnel in Oak Ridge, found 5.6% and 3.1% respectively reported seeing ball lightning. A Scientific American article summarized the study as having found that ball lightning had been seen by 5% of the population of the Earth. Another study analyzed reports of more than 2,000 cases.
Gervase of Canterbury The chronicle of Gervase of Canterbury, an English monk, contains what is possibly the earliest known reference to ball lightning, dated 7 June 1195. He states, "A marvellous sign descended near London", consisting of a dense and dark cloud, emitting a white substance that grew into a spherical shape under the cloud, from which a fiery globe fell towards the river.
Physicist Emeritus Professor Brian Tanner and historian Giles Gasper of Durham University identified the chronicle entry as probably describing ball lightning, and noted its similarity to other accounts:
Great Thunderstorm of Widecombe-in-the-Moor
One early account reports on the Great Thunderstorm at a church in Widecombe-in-the-Moor, Devon, in England, on 21 October 1638. Four people died and approximately 60 suffered injuries during a severe storm. Witnesses described an ball of fire striking and entering the church, nearly destroying it. Large stones from the church walls were hurled onto 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 sulfurous odor 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. Because of the fire and sulphur smell, contemporaries explained the ball of fire as "the devil" or as the "flames of hell". Later, some blamed the entire incident on two people who had been playing cards in the pews during the sermon, thereby incurring God's wrath.
The sloop Catherine and Mary In December 1726, a number of British newspapers printed an extract of a letter from John Howell of the sloop Catherine and Mary:
HMS Montague One particularly large example was reported "on the authority of Dr. Gregory" in 1749:
Georg Richmann A 1753 report recounts lethal ball lightning when professor Georg Richmann of Saint Petersburg, Russia, constructed a kite-flying apparatus similar to Benjamin Franklin's proposal a year earlier. Richmann was attending a meeting of the Academy of Sciences when he heard thunder and ran home with his engraver to capture the event for posterity. While the experiment was under way, ball lightning appeared, travelled down the string, struck Richmann's forehead and killed him. The ball had left a red spot on Richmann's forehead, his shoes were blown open, and his clothing was singed. His engraver was knocked unconscious. The door-frame of the room was split and the door was torn from its hinges.
HMS Warren Hastings An English journal reported that during an 1809 storm, three "balls of fire" appeared and "attacked" the British ship . The crew watched one ball descend, killing a man on deck and setting the main mast on fire. A crewman went out to retrieve the fallen body and was struck by a second ball, which knocked him back and left him with mild burns. A third man was killed by contact with the third ball. Crew members reported a persistent, sickening sulphur smell afterward.
Ebenezer Cobham Brewer Ebenezer Cobham Brewer, in his 1864 US edition of A Guide to the Scientific Knowledge of Things Familiar, discusses "globular lightning". He describes it as slow-moving balls of fire or explosive gas that sometimes fall to the earth or run along the ground during a thunderstorm. He said that the balls sometimes split into smaller balls and may explode "like a cannon".
Wilfrid de Fonvielle In his book Thunder and Lightning, translated into English in 1875, French science-writer Wilfrid de Fonvielle wrote that there had been about 150 reports of globular lightning:
Tsar Nicholas II Nicholas II, the final tsar of the Russian Empire, reported witnessing a fiery ball as a child attending church in the company of his grandfather Alexander II.
Aleister Crowley British occultist Aleister Crowley reported witnessing what he referred to as "globular electricity" during a thunderstorm on Lake PasquaneyThere is no present-day Lake Pasquaney in New Hampshire, United States. New Hampshire's Newfound Lake has a Camp Pasquaney. However, part of the lake is known as Pasquaney Bay. in New Hampshire, United States, in 1916. He was sheltered in a small cottage when he, in his own words,
Roger Clifton Jennison Jennison, of the Electronics Laboratory at the University of Kent, described his own observation of ball lightning in an article published in Nature in 1969:
Other accounts
Willy Ley discussed a sighting in Paris on 5 July 1852 "for which sworn statements were filed with the French Academy of Sciences". During a thunderstorm, a tailor living next to Church of the Val-de-Grâce saw a ball the size of a human head come out of the fireplace. It flew around the room, reentered the fireplace, and exploded in and destroyed the top of the chimney. On 30 April 1877, a ball of lightning entered the Golden Temple at Amritsar, India, and exited through a side door. Several people observed the ball, and the incident is inscribed on the front wall of Darshani Deori. On 22 November 1894, an unusually prolonged instance of natural ball lightning occurred in Golden, Colorado, which suggests it could be artificially induced from the atmosphere. The Golden Globe newspaper reported: On 22 May 1901, in the Kazakh city of Uralsk in the Russian Empire (now Oral, Kazakhstan), "a dazzlingly brilliant ball of fire" descended gradually from the sky during a thunderstorm, then entered into a house where 21 people had taken refuge, "wreaked havoc with the apartment, broke through the wall into a stove in the adjoining room, smashed the stove-pipe, and carried it off with such violence that it was dashed against the opposite wall, and went out through the broken window". The incident was reported in the Bulletin de la Société astronomique de France the following year.Mark Stenhoff (1999) Ball Lightning: An Unsolved Problem in Atmospheric Physics. Kluwer Academic/Plenum, p. 70. In July 1907, ball lightning hit the Cape Naturaliste Lighthouse in Western Australia. Lighthouse-keeper Patrick Baird was in the tower at the time and was knocked unconscious. His daughter Ethel recorded the event. Ley discussed another incident in Bischofswerda, Germany. On 29 April 1925, multiple witnesses saw a silent ball land near a mailman, move along a telephone wire to a school, knock back a teacher using a telephone, and bore perfectly round coin-sized holes through a glass pane. of wire was melted, several telephone poles were damaged, an underground cable was broken, and several workmen were thrown to the ground but unhurt. An early reference to ball lightning appears in a children's book set in the 19th century by Laura Ingalls Wilder. The books are considered historical fiction, but the author always insisted they were descriptive of actual events in her life. In Wilder's description, three separate balls of lightning appear during a winter blizzard near a cast-iron stove in the family's kitchen. They are described as appearing near the stovepipe, then rolling across the floor, only to disappear as the mother (Caroline Ingalls) chases them with a willow-branch broom.