Encyclopedia
Ball lightning reportedly takes the form of a short-lived, glowing, floating object often the size and shape of a
basketball, but it can also be
golf ball sized or smaller. 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 still disagree on whether it is a real phenomenon.
Reports
Ball lightning
discharges were once thought to be extremely rare occurrences, but recent research shows that a few percent of the US population have been witnesses. Surveys have been taken of eyewitness accounts by at least 3000 people.
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.
Ball lightning reportedly tends to
float 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. The longest dimension reported is between fifteen and forty centimeters. Many are
red to
yellow in color, sometimes transparent, and some contain radial filaments or sparks. Other colors, 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.
Ball lightning was reported in
World War II as "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. Other accounts place ball lightning as appearing over a kitchen stove or wandering down the aisle of an
airliner. One report described ball lightning engulfing and following a car, causing the electrical supply to overload and fail.
Historical and fictional accounts
One of the earliest reported, and most destructive, occurrences is said to have taken place during The Great Thunderstorm at
Widecombe-in-the-Moor,
Devon, in
England, on October 21 1638. Four people died and around 60 were injured when what appeared to have been ball lightning struck a church.
Another reference to ball lightning appears in a children's book set in the 1800s 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 chases them with a willow-branch broom.
Notorious British occultist
Aleister Crowley also reported witnessing what he referred to as "globular electricity" during a thunderstorm on Lake Pasquaney in
New Hampshire in 1916. As related in his Confessions, he was sheltered in a small cottage when he "noticed, with what I can only describe as calm amazement, that a dazzling globe of electric fire, apparently between six and twelve inches in diameter, was stationary about six inches below and to the right of my right knee. As I looked at it, it exploded with a sharp report quite impossible to confuse with the continuous turmoil of the lightning, thunder and hail, or that of the lashed water and smashed wood which was creating a pandemonium outside the cottage. I felt a very slight shock in the middle of my right hand, which was closer to the globe than any other part of my body."
A famous anecdote from 1753 depicts ball lightning as having violent potential. Professor Georg Richmann, of
Saint Petersburg, Russia created a kite flying apparatus similar to that built by Benjamin Franklin a year earlier. He was attending a meeting of the Academy of Sciences, when he heard
thunder. The Professor ran home with his engraver to capture the event for posterity. While the experiment was underway, ball lightning appeared, collided with Richmann's head and killed him, leaving a red spot. His shoes were blown open, parts of his clothes singed, the engraver knocked out; the doorframe of the room was split, and the door itself torn off its hinges.
Laboratory experiments
Many attempts have been made over the years to produce ball lightning in the laboratory, but it is easy to mistake other phenomena for ball lightning. Most prominent among these are glowing spheres produced by high-energy arcs between metal electrodes. Such arcs often expel small droplets of molten metal that are heated to extremely high temperatures. Because of their high heat content, these droplets will continue to glow quite brightly for several seconds after landing on a floor or other surface, and their odd physical characteristics can cause them to roll, still glowing brightly, for some distance after landing. They thus mimic the most common description of ball lightning before cooling down into a small speck of metallic dust. The most familiar instance of these glowing spheres is the "weld spatter" usually seen during arc welding operations. The spheres can also be produced when a switch carrying very large electric currents is operated improperly, or during certain grinding or other machining operations.
Some laboratory experiments claim to have produced ball lightning, but there is no consensus that the phenomenon reproduced is related to the natural one. The natural occurrences are, by their nature, difficult to document accurately. Consequently, many scientists continue to dispute the existence of ball lightning as a distinct physical phenomenon. In one such occurrence, Singer reports that staff at the
Cavendish Laboratory, Cambridge apparently saw ball lightning, although Brian Pippard, the Head of Department, was skeptical of its reality.
In February 2006, scientists at
Tel Aviv University claimed to have produced ball lightning in the lab using a and ceramic substrate.. More recently researchers at the Max Planck Institute for Plasma Physics successfully recreated the phenomenon using a relatively simple water tank experiment. The experiment involves two electrodes placed in a small tank of salt water, with one electrode covered by a clay tube. A large current of over 60 amps was then run through the water for 150 milliseconds, vaporizing water inside the clay tube and causing a ball of
plasma to appear above the tank for 0.3 seconds. Although the plasma glows brightly it was found to be quite cold, much like a neon tube
.
Analysis
An early attempt to explain ball lightning was recorded by
Nikola Tesla in 1904.
Difficult features of the lightning include its persistence and its near-neutral
buoyancy in air. A popular hypothesis is that ball lightning is a highly ionized plasma contained by self-generated magnetic fields: a
plasmoid. This hypothesis is not initially credible. If the gas is highly ionized, and if it is near thermodynamic equilibrium, then it must be very hot. Since it must be in pressure equilibrium with the surrounding air, it will be much lighter and hence float up rapidly. Magnetic fields, if present, might provide the plasmoid's coherence, but will not reduce this buoyancy. In addition a hot plasma cannot persist for long, because of recombination and
heat conduction.
There may, however, be some novel form of plasma for which the above arguments do not fully apply. For example, a plasma may be composed of negative and positive ions, rather than electrons and positive ions. In that case, the recombination may be rather slow even at ambient temperature. One such theory involves positively charged
hydrogen and negatively charged
nitrites and
nitrates . In this theory, the role of the ions as seeds for the condensation of water droplets is important.
A proposed explanation for the numerous colors reported for ball lightning is the following known gas phase chemoluminescent reaction:
- NO+O3 ? NO2[?]+ O2
Broadband visible light is emitted from the NO2 as it reverts to a lower energy state. This explanation is supported by the numerous witness accounts of the presence of ozone.
Some researchers suggest that ball lightning has a more diverse range of properties than previously thought . Japanese investigators 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 and holes into the ground. Ball lightning is also said to have an odd motion such as looping and the appearance of bouncing along the ground.
Other suggestions include:
- that ball lightning may represent the missing science of burning natural vortices. This theory by Coleman was published in Weather and in the 2006 Journal of Scientific Exploration 20,2,215-238.
- that some stored chemical energy is slowly being released. see Abrahamson, J. and J. Dinniss . Ball lightning caused by oxidation of nanoparticle networks from normal lightning strikes on soil. Nature 403:519-521.
- that ball lightning is some form of induction phenomenon , ball lightning having allegedly been witnessed inside metal aircraft.
- that it is an optical illusion similar to the aftereffect of a photographer's flash directed into a person's eyes.
- There is also a theory that poltergeists and human combustions might be subdivisions of ball lightning phenomena http://www.newscientist.com/article.ns?id=dn1720
Esoteric explanations
Ball lighting has been connected to reports of several supernatural phenomena, ranging from will o' the wisps to
UFOs. Some people believe the ball lightning phenomena are
ghosts or spirits. References can be seen in the will o' the wisp and other spirits that take the guise of orbs of light. Some UFO skeptics have suggested that many apparent
close encounters are actually observations of ball lightning. UFO enthusiasts report seeing ball lightning often at
crop circle sites and believe them to be some kind of intelligence or come from some kind of intelligence while not denying that it is indeed ball lightning.
Another exotic explanation that has been offered for ball lightning is that it is the passage of microscopic
primordial black holes through the Earth's atmosphere. No such tiny black holes have ever been positively detected, and it is uncertain whether they would have the physical properties described by ball lightning if they did in fact exist and in great enough quantity to account for ball lightning reports. This explanation also would not account for their alleged co-occurrence with electrical storms.
Among the ancients of
Japanese mythology, there is a myth that ball lightning is the wrath of the thunder god,
Raijin from
Japanese mythologyQuotations
- "...Our conclusion is that these fireballs are primarily RF in origin, and not nuclear phenomena..." - Corum
- "...No theory of ball lightning exists which can account for both the degree of mobility that the ball exhibits and for the fact that it does not rise...." - Talbot
See also
Further reading
References
External links
- — the secret of ball lightning and a new field of science and technology*
- and — Various articles, experiments, and information on Ball lightning
- — Alternative "toaster" Microwave Experiments***
