Earth lights are a rare anomalous light phenomenon, mistaken throughout history as dragons, UFOs, and ball lightning before being recognised as a separate category. One leading theory is that they are produced by tectonic strain in minor fault lines, so that they are literally generated by the earth.
In America they've been called "spooklights" or "ghost lights" since at least the 1950s, but Persinger and Lafrenière were the first scientists to recognise the phenomenon, in the late 1970s. The lights were renamed and brought to wider public attention by Paul Devereux in 1982 with his publication "Earth Lights".
They appear in many colours, shapes, and sizes, though the basketball-sized globular orange variety seems most common. Most sightings occur at night, when some lights can be seen from miles around. They're reported to be able to move against the wind and reach extraordinary speeds. Their terrestrial nature means that though many sightings are sporadic, there are some locations where they appear relatively often. It's through studying these hotspots, such as Hessdalen in Norway and the Engligh Pennines, that their characteristics become evident.
Since earth lights are a local phenomenon, the "local hotspots" that give rise to them often become ingrained into local culture and folklore, and supernatural stories accrue round them over the years. In Ireland, for example, the lights are faeries; in Asia they're gods; and in America they're the ghosts of Native Americans.
The word "haunt" is often used to describe the tendency for earth lights to be bound to specific locations (e.g. Devereux 1989, p.25), exposing the general perception in folklore of the lights as being the spirits of the departed. For example, there was a successful plot to kill the King of England, St. Edward the Martyr, in 978 by his stepmother Queen Elfrida, who wanted her own son to take the throne. The deed was done in Corfe Castle in Dorset. It's recorded that "[a] year after the murder a pillar of fire was seen over the place where the body was hidden, lighting up the whole area. This was seen by some inhabitants of Wareham, who raised the body."
On 9th March 1170, a "wonderfully large dragon" was seen over St. Ostwyth in Essex, and had been "borne up from the Earth through the air". It went on to destroy a house*. (Devereux 1989, p.36, attributes this to Ralph Niger, i.e. Radulphus Niger, a mediaeval chronicler and theologian born in c.1140).
Even more extravagant displays are recorded. The sky over Nuremburg in 1561 was said to be filled with all manner of shining tubes and crosses, battling with one another, though of course this is difficult to interpret in a modern scientific context—it could have been the aurora borealis, which is recorded to have displayed itself over Nuremburg thirty years later. More concretely, in 1900 two mountains in the mesopotamian region were said to have played a kind of large scale tennis with one another, exchanging balls of light:
This exchange (in 1900?) ensued between Keklujek and Ziaret, two peaks in the Taurus Mountains south of Harpoot, Mesopotamia. "The weapons were balls of light," the respected climatologist Ellsworth Huntington was told by resident natives. "A ball of fire is sometimes seen to start from one mountain and to go like a flash to the other." This fiery bombardment occurred day or night, but only when the sky was clear. Wrote Huntington in Monthly Weather Review (July 1900): "I became thoroughly convinced of its truth."
— Larry E. Arnold
For more information on this, see the full reports in Lights in the Taurus Mountains. In the 20th century, with the advent of war came foo fighters (WWII, Atlantic) and ghost rockets (post-WWII, Scandinavia). The interpretation of mysterious lights as a function of the context in which they are seen has always made the historical record difficult to reinterpret in an objective scientific manner. Yet burgeoning attempts at both that and the collection of new evidence started in the latter half of the century.
It is Michael Persinger who coined the phrase "Anomalous Luminous Phenomena" to avoid having to use the term UFO, with its negative connotations. The Tectonic Strain Theory that he posits with Gyslaine Lafrenière states that ALP are "natural events, generated by stresses and strains within the earth's crust", and goes on to submit that the magnetic disturbances associated with the strains can mar the observational integrity of witnesses to the events. Their work predates Devereux by several years, but Devereux devoted as much work to singling out and identifying the phenomenon as he did in offering possible explanations for the mechanism behind it.
On 3rd November 1996, the British science show Equinox aired a program called Identified Flying Objects mainly featuring Paul Devereux, but also containing interviews with Derr, Persinger, Akers, and some of the other personalities involved in earth light research (this is how my attention was drawn to the phenomenon). Here's how the show was described at the time: "Using extraordinary earthlight footage and expert opinion, tonight Equinox travels to Marfa, and to other earthlight spots in Mexico, Norway, and the Australian Outback, to witness these investigations that may take science into a new era - the era of Identified Flying Objects." Accompanying the show was a booklet produced by the Broadcasting Support Services.
In 2003, Dr. Marsha Adams along with some other prominent researchers including Prof. Erling Strand started the IEA, the International Earthlights Alliance, a research organisation devoted to the study of earth lights.
Most of these historical events were what are known as "flaps": they took place over a short time period and then went away. But the most interesting earth light events are those that occur in a specific location over a long period of time, and there are quite a few locations worldwide that are still active today. The most famous of these are probably Hessdalen, in Norway; the Min Min Lights, in Australia; the Bang Fai Phaya Naga, in Thailand; and the Hornet Spooklight and Marfa Lights, in America. There are an almost innumerable amount of locations in total though, for example even several in just the relatively small land space of the British Isles.
This propensity of the lights to occur in specific locations makes scientific study slighly more possible. One of the most well known studies is that of Project Hessdalen, established in 1983 by Prof. Erling Strand under the aegis of Østfold University College. During the early 1980s the lights, known locally as Hessdalsphenomena, were seen hundreds of times per year. Whilst activity has decreased somewhat now, there are still up to twenty sightings per year, and research is ongoing.
Another famous location where Earth Lights are seen is Boulia, in Queensland, Australia. There the lights are called "min-min lights" after the Min Min Hotel from which they were first seen by westerners. The word "min" is an Aboriginal word of unknown meaning. In April 2000, the Australian government opened a new Min Min Encounter Centre that cost $2M ASD to build. The original hotel burned down in 1918—according to Christopher Leonard in Outback Australia, the Permanent Frontier*—but has been recreated inside the new centre. Prof. Jack Pettigrew of the University of Queensland caused a stir in 2003 with an excellent study of his called The Min Min Light and Fata Morgana published in Clinical and Experimental Optometry that claims the Min-Min lights to be merely refracted lights from up to 300km away made visible by temperature inversions.
Pettigrew isn't the first to have claimed that the lights are caused by temperature inversions, but is the first to have actually experimented with producing the effect himself. The mirage explanation is often used to explain earth lights, and likely does account for a large proportion of the finds, but it has been pointed out that the Min Min light has been visible for over 70 years, since even before the introduction of cars (@@ ask Prof. Pettigrew about this?).
Maureen Kozicka wrote a book about the lights called The Mystery of the Min Min Light, which is a collection of stories collected from the field. The book is unavailable on Amazon, and I've been unable to locate even its ISBN number. It was published by Bolton Imprint. According to Hayman (2004), "Kozicka in her book lists the decades in which the sightings occur. The most frequent sightings (36) occur between 1950 and 1959, with only 12 between 1940 - 49 and 16 in the following decade."
The bung fai paya nak, or Naga fireballs in English, spring up every October from the Mekong River in Thailand. Even Time magazine has covered the event, reporting that "each year, anything from 200 to 800 of the fiery orbs are sighted along a 100-kilometer stretch of the river". The October full moon is the most likely time for the orbs to appear, and as a result up to 400,000 people visit the river to catch their appearance*. The rate at which they are seen on that night is variable, and may depend on the weather: in rainy years, less appear*?.
Local tradition states that the fireballs are from the nak, a serpent from Buddhist legend. Modern science disagrees, of course. There was quite a controversy in Thailand recently when a news station there, iTV, presented a programme stating that the fireballs were faked, and nothing more than tracer rounds fired by the Lao army (the river denotes the border between Thailand and Laos). People living by the river claim that this is absurd since the lights have been seen along the river for decades.
The official scientific line, corroborated by a statement from Thailand's Ministry of Science and Technology, is that the fireballs are nothing but natural phosphene and methane gas being released from the river. This is the same mechanism as is commonly proposed to be behind Will-o'-the-wisp. Their investigations, with Mahidol University, continue, and though many people have accepted this explanation, there are still disagreements. Professor Montri Boonsaneur, for example, is quoted in the Time article as saying that bubbles of methane could not be propagated by the turbulent river.
Reports of when in the day the fireballs actually appear vary, but generally place them at being early evening: after sunset, but before midnight. The first moon of October is also the last month of the Buddhist three-month lent*, so people flock to Phon Phisai, Sung Kom, Sri Chiang Mai, and Pak Khad districts*, not only to see the Bang Fai Phaya Nark (there are almost as many spelling variants as there are visitors) but to celebrate the end of that period. In 2005 it falls on Tuesday, 18th October*, and it looks to be quite the occasion.
There are also many locations in the United States where earth lights are seen, though they go by the names "ghost lights", "spooklights", or the local name of the light there. The most famous examples include the Maco Station Light (North Carolina), Brown Mountain Light (North Carolina), Hornet Spooklight (Missouri; see also the Hornet Spooklight Booklet), Marfa Lights (Texas), the Yakima Lights (Washington), Anson Light (Texas), Dover Light (Arkansas), and the Hebron Light (Maryland). The St. Louis Light (Saskatchewan, Canada) is also rather famous.
As is usual when you have a relatively rare phenomenon for which there is no standard scientific term, a range of synonyms for the phenomenon will result. This is especially true for the Will-o'-the-Wisp, for which there may be as many as thirty terms just in English; but it's also true for earth lights. Here are some of the more common synonyms:
In an attempt to find out which of these is the most commonly used, on the 3rd October 2006 I took pairwise Googlecounts of each of the terms. This was to minimise the amount of false positives in the results. For example, a lot of the search results for "earth lights" are actually about NASA photographs of the earth at night; but perhaps all of the results for [earth-lights spook-lights] are going to be about the anomalous light phenomena. Once the average of each of the pairings are taken, this is the result:
|earth-lights||716.2||88, 815, 574, 904, 1200|
|spook-lights||691.2||16, 1200, 743, 716, 781|
|"nocturnal lights"||527.4||23, 904, 709, 220, 781|
|"geophysical meteors"||463.8||6, 815, 46, 709, 743|
|ghost-lights||317.8||33, 574, 46, 220, 716|
|"Anomalous Luminous Phenomena"||33.2||88, 6, 33, 23, 16|
"Earth lights" just marginally edges out "spooklights" to the top spot, even though it's a relative neologism. It's also remarkable that "nocturnal lights" and "geophysical meteors" score quite highly over "ghost lights". It may be that the damping algorithm could be improved somewhat, but it's an interesting metric nonetheless. For reference, here are the raw Googlecounts performed on the same day:
There are also local terms for earth lights, such as Hessdalsphenomenon that appears to have been coined by Prof. Erling Strand to pertain to the lights in Hessdalen. Even I once coined an alternative word for earth lights, in a whimsical attempt to make references to them more easy to find on search engines: geolumina. I'm aware that it's a greek prefix tacked to a latin suffix (or vice versa), but as C.P. Scott once said: "Television? The word is half Latin and half Greek. No good can come of it."
On the phrase "ghost lights"specifically, the OED has a citation dating from 1879: "Folk-Lore Sept. 215 A. F. says that he himself saw what they call a ghost-light.", with a probably erroneous note "ghost-light, ?= CORPSE-CANDLE 2". It doesn't mention any of the other forms, so far as I can tell. It would probably be difficult to trace the antiquity of the word spooklight, especially; you'd have to sift a lot of local, small-town American publications most likely.
This is a list of books or chapters whose primary focus is the earth lights phenomenon, under whatever guise.