St. Elmo's FireSt. Elmo's Fire
is an electro-luminescent discharge caused by ionisation
of the air during thunderstorms. inside of a strong electric field. Benjamin Franklin
correctly observed in 1749
that it is electric in nature. Physically, it is a bright bluish-white glow, appearing like fire in some circumstances, often in double or triple jets, from tall, sharply-pointed structures such as masts, spires and chimneys. Although referred to as "fire," St. Elmo's Fire is in fact a kind of plasma
caused by a massive atmospheric potential difference
. It can also appear between the tips of cattle horns during a thunderstorm
, or sharp objects in the middle of a tornado, but is not the same phenomenon as ball lightning
, although it is related.
In ancient Greece, the appearance of a single one was called Helena and two were called Pollux and Castor. It is named after Erasmus of Formiae, the patron of sailors, because it would appear most often on pointed objects of a ship at sea. St. Elmo's Fire was so-named because the phenomenon commonly occurs at the mastheads of ships during thunderstorms at sea, and St. Elmo is the patron saint of mariners, who held its appearance to be auspicious.
References to St. Elmo's Fire, often know as "corposants" or "corpusants" from the Spanish Cuerpos Santos (Holy Bodies), can be found in the works of Julius Caesar, Pliny, Antonio Pigafetta's journal of his voyage with Ferdinand Magellan and Herman Melville.
- "'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 were silently burning in the sulphurous air, like three gigantic wax tapers before an altar."
- Herman Melville, Moby Dick.
St. Elmo's Fire was the defining movie of the 1980s brat pack
which consisted of Ally Sheedy, Rob Lowe
, Demi Moore
, Molly Ringwald
, Judd Hirsch
and Emilio Estevez