What visible electric discharge on the mast of a ship or the wing of an airplane during an electrical storm is named after the fourth-century patron saint of sailors, and is also the title of a 1985 movie starring Robe Lowe and Demi Moore?

The captivating natural phenomenon known as Saint Elmo's Fire is a luminous electrical discharge that appears on pointed objects like ship masts, church spires, or airplane wings during electrical storms. It's a form of plasma, created when the electric field around an object becomes strong enough to ionize the air molecules, producing a faint blue or violet glow, often accompanied by a hissing or buzzing sound. While it looks like fire, it's not actual combustion but rather a continuous electrical spark, similar to the glow seen in neon tubes. Sailors throughout history, including figures like Magellan and Columbus, have observed this eerie glow, often considering it a good omen despite the stormy conditions.

The name "Saint Elmo's Fire" is derived from Saint Erasmus of Formia, a 4th-century Christian saint also known as Saint Elmo. He is revered as the patron saint of sailors. Legend has it that Saint Elmo continued preaching even after a thunderbolt struck near him, leading sailors to invoke his protection during storms. The appearance of this glowing discharge on their ship's masts was then interpreted as a sign of his watchful presence and protection, offering comfort and hope in treacherous seas.

Beyond its scientific explanation and historical ties to maritime folklore, Saint Elmo's Fire also holds a place in popular culture. It is the title of a 1985 American coming-of-age film. The movie stars a group of well-known actors, often referred to as the "Brat Pack," including Rob Lowe and Demi Moore, along with Emilio Estevez, Andrew McCarthy, Judd Nelson, Ally Sheedy, and Mare Winningham. The film follows a group of recent college graduates as they navigate life, love, and adulthood in Washington, D.C.