St. Elmo's fire

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St. Elmo's fire is an electrical weather phenomenon in which luminous plasma is created by a coronal discharge originating from a grounded object in an atmospheric electric field (such as those generated by thunderstorms or thunderstorms created by a volcanic explosion).

St. Elmo's fire is named after St. Erasmus of Formiae (also called St. Elmo), the patron saint of sailors. The phenomenon sometimes appeared on ships at sea during thunderstorms, and was regarded by sailors with superstitious awe, accounting for the name. Alternatively, Peter Gonzalez is said to be the St. Elmo after whom St. Elmo's fire has its name.

Ball lightning is often erroneously identified as St. Elmo's fire. They are separate and distinct meteorological phenomena.^[1]

Contents 1 Observation 2 Scientific explanation 3 Historical observations 4 In literature 5 In popular culture 6 References 7 See also 8 External links

[edit] Observation

Physically, St. Elmo's fire is a bright blue or violet glow, appearing like fire in some circumstances, from tall, sharply pointed structures such as lightning rods, masts, spires and chimneys, and on aircraft wings. St. Elmo's fire can also appear on leaves, grass, and even at the tips of cattle horns^[2]. Often accompanying the glow is a distinct hissing or buzzing sound.

In 1750, Benjamin Franklin hypothesized that a pointed iron rod during a lightning storm would light up at the tip, similar in appearance to St. Elmo's fire.^[3][4]

[edit] Scientific explanation

Although referred to as "fire", St. Elmo's fire is, in fact, plasma. The electric field around the object in question causes ionization of the air molecules, producing a faint glow easily visible in low-light conditions. Approximately 1,000 - 30,000 volts per centimetre is required to induce St. Elmo's fire; however, this number is greatly dependent on the geometry of the object in question. Sharp points tend to require lower voltage levels to produce the same result because electric fields are more concentrated in areas of high curvature, thus discharges are more intense at the end of pointed objects^[5].

St. Elmo's fire and normal sparks both can appear when high electrical voltage affects a gas. St. Elmo's fire is seen during thunderstorms when the ground below the storm is electrically charged, and there is high voltage in the air between the cloud and the ground. The voltage tears apart the air molecules and the gas begins to glow.

The nitrogen and oxygen in the earth's atmosphere causes St. Elmo's fire to fluoresce with blue or violet light; this is similar to the mechanism that causes neon lights to glow^[5].

[edit] Historical observations

In ancient Greece, the appearance of a single one was called Helena and two were called Castor and Pollux. Occasionally, it was associated with the Greek element of fire, as well as with one of Paracelsus's elementals, specifically the salamander, or, alternatively, with a similar creature referred to as an acthnici ^[6].

Welsh mariners knew it as canwyll yr ysbryd ("spirit-candles") or canwyll yr ysbryd glân ("candles of the Holy Ghost"), or the "candles of St. David"^[7].

References to St. Elmo's fire, also known as "corposants" or "corpusants" from the Portuguese corpo santo^[8] ("holy body"), can be found in the works of Julius Caesar (De Bello Africo, 47), Pliny the Elder (Naturalis Historia, book 2, par. 101) , Herman Melville, and Antonio Pigafetta's journal of his voyage with Ferdinand Magellan. St. Elmo's fire was a phenomenon described in The Lusiads.

Charles Darwin noted the effect while aboard the Beagle. He wrote of the episode in a letter to J.S. Henslow that one night when the Beagle was anchored in the estuary of the Río de la Plata:

"Everything is in flames, — the sky with lightning, — the water with luminous particles, and even the very masts are pointed with a blue flame."^[9]

In Two Years Before the Mast, Richard Henry Dana, Jr. describes seeing a a corposant in the southern Atlantic Ocean: "There, directly over where we had been standing, upon the main top-gallant mast-head, was a ball of light, which the sailors name a corposant (corpus sancti), and which the mate had called out to us to look at. They were all watching it carefully, for sailors have a notion, that if the corposant rises in the rigging, it is a sign of fair weather, but if it comes lower down, there will be a storm."^[10]

Many Russian sailors have seen them throughout the years. To them, they are "Saint Nicholas" or "Saint Peter's lights"^[7]. They were also sometimes called St. Helen's or St. Hermes' fire, perhaps through linguistic confusion.^[11]

St Elmo's fire were also seen during the 1955 Great Plains tornado outbreak in Kansas and Oklahoma (US) ^[12].

Accounts of Magellan's first circumnavigation of the globe refer to St. Elmo's fire being seen around the fleet's ships multiple times off the coast of S. America. The sailors saw these as favorable omens.

Among the phenomena experienced on British Airways Flight 9 on 24 June 1982 were glowing light flashes along the leading edges of the aircraft, which were seen by both passengers and crew. This has been attributed to the Saint Elmo's fire effect, caused by static electricity built up during the airplane's passage through a cloud of volcanic ash.

[edit] In literature

One of the earliest references of St. Elmo's fire made in fiction can be found in Ludovico Ariosto's epic poem Orlando furioso (1516). It is located in the 17th canto (19th in the revised edition of 1532) after a storm has punished the ship of Marfisa, Astolfo, Aquilant, Grifon, and others, for three straight days, and is positively associated with hope:

"But now St. Elmo's fire appeared, which they had so longed for, it settled at the bows of a fore stay, the masts and yards all being gone, and gave them hope of calmer airs."

In Shakespeare's The Tempest (c. 1623), Act I, Scene II, St. Elmo's fire acquires a more negative association, appearing as evidence of the tempest inflicted by Ariel according to the command of Prospero:

"PROSPERO

Hast thou, spirit,

Perform'd to point the tempest that I bade thee?

ARIEL

To every article.

I boarded the king's ship; now on the beak,

Now in the waist, the deck, in every cabin,

I flamed amazement: sometime I'ld divide,

And burn in many places; on the topmast,

The yards and bowsprit, would I flame distinctly,

Then meet and join."

Later 18th Century and 19th Century literature associated St. Elmo's fire with bad omen or divine judgment, coinciding with the growing conventions of Romanticism and the Gothic novel. For example, in Ann Radcliffe's The Mysteries of Udolpho (1794), during a thunderstorm above the ramparts of the castle (Vol III, Ch.IV):

"'And what is that tapering of light you bear?' said Emily, 'see how it darts upwards,—and now it vanishes!'

'This light, lady,' said the soldier, 'has appeared to-night as you see it, on the point of my lance, ever since I have been on watch; but what it means I cannot tell.'

'This is very strange!' said Emily.

'My fellow-guard,' continued the man, 'has the same flame on his arms; he says he has sometimes seen it before...he says it is an omen, lady, and bodes no good.'

'And what harm can it bode?' rejoined Emily.

'He knows not so much as that, lady.'"

And in Herman Melville's Moby-Dick (1851), Ch. CXIX, "The Candles", during which the ship Pequod is struck head-on by a typhoon:

"'Look aloft!' cried Starbuck. 'The corpusants! the corpusants!'

All the yard-arms were tipped with a pallid fire; and touched at each tri-pointed lightning-rod-end with three tapering white flames, each of the three tall masts was silently burning in that sulphurous air, like three gigantic wax tapers before an altar. […]

[Stubb] cried, "The corpusants have mercy on us all!" […]

...in all my voyagings seldom have I heard a common oath when God's burning finger has been laid on the ship..."

There is also a possible reference^[13] to St. Elmo's fire in Samuel Taylor Coleridge's The Rime of the Ancient Mariner (1798):

"About, about, in reel and rout

The death-fires danced at night;

The water, like a witch's oils,

Burnt green, and blue, and white."

There is a reference to Saint Elmo's fire in Kurt Vonnegut's Slaughterhouse-Five. Billy Pilgrim, the protagonist, "had been seeing Saint Elmo's fire, a sort of electronic radiance around the heads of his companions and captors. It was in the treetops and on the rooftops of Luxembourg, too. It was beautiful" (Vonnegut 81).

Saint Elmo's fire is also mentioned in Gabriel Garcia Marquez's Chronicle of a Death Foretold. "The moon was high in the sky and the air was clear, and at the bottom of the precipice you could see the trickle of light from the Saint Elmo's fire in the cemetery."

In Jonathan Safran Foer's novel Extremely Loud and Incredibly Close, the protagonist Oscar Schell discusses St. Elmo's fire while atop the Empire State Building.

[edit] In popular culture

• In the Capcom video game Devil May Cry, Dante must retrieve the "fire of St. Elmo".
• In the comic book Tintin in Tibet by Herge, Captain Haddock's ice axe is hit by St. Elmo's fire.
• In the 1956 film Moby Dick starring Gregory Peck, the phenomon occurs shortly before the final climactic scene.
• In the 1961 movie The Last Sunset St. Elmo's fire is depicted. While perched above a herd of cattle they have been driving, Kirk Douglas points out the phenomenon to Dorothy Malone's character. Blue light is visible throughout the herd.
• "St. Elmo's Fire" is a song by Brian Eno on his 1975 album Another Green World. "And we saw St. Elmo's fire / Splitting ions in the ether."
• In 1993 Ui and Stereolab collaborated on 4 versions of Eno's St. Elmo's Fire on the EP Fires under the group name Uilab.
• St Elmo's fire is also shown in the 1980s Japanese-French cartoon, The Mysterious Cities of Gold.
• In the 1980s version of Astroboy, St. Elmo's fire appears atop Viking ships in the episode "The World of Odin".
• In Stephen King's 1983 book Pet Sematary, Jud warns Louis that he might see St. Elmo's fire while on the path to bury his dead cat Church.
• The 1985 movie St. Elmo's Fire, while not a literal interpretation of the phenomenon, is metaphorically related. The picture was nominated for Best Album of Original Score Written for a Motion Picture or Television Special in 1986. The title track by John Parr was a #1 hit.
• In the novel The Reality Dysfunction, by Peter Hamilton, St. Elmo's fire is seen when the possessed burn through a polyp crane on Atlantis.
• In the popular RPG Final Fantasy VII, St. Elmo's fire is used as an attack by a "ghost ship"-monster found in the underwater tunnel on the way to the submarine.
• In the Kurt Vonnegut book The Sirens of Titan, Winston Niles Roomford, the book's main character, glows with St. Elmo's fire before his untimely fizzling out of existence within the solar system to become omnipotent throughout the galaxy.
• St. Elmo's fire appears on the cattle horns during a storm in Lonesome Dove and in an episode of Rawhide (TV series) titled The Incident of the Blue Fire.
• In the Terry Pratchett novel Jingo, a form of St. Elmo's fire appears, although the characters refer to it as St. Ungulant's fire. Due to the magical nature of the disc, the 'fire' is edged in octarine.
• "St. Elmo's Fire" is a song by Michael Franks on his "Art of Tea" album.
• In the 1956 film, Earth vs. the Flying Saucers alien observation probes are mistaken for St. Elmo's fire.
• In the online game AdventureQuest, there is a monster named 'St. Elmo's Fire' that is a parody of both this phenomenon and the Sesame Street character, Elmo.
• In the RPG Jade Cocoon 2, St. Elmo's Fire is one of the final levels.

[edit] References

[edit] See also

• Ball lightning
• Naga fireballs
• Will o' the wisp

[edit] External links

• Video of St. Elmo's fire (around 2:00 in the left window)
• http://www.islandnet.com/~see/weather/elements/stelmo.htm