Nabla symbol

The name comes, by reason of the symbol's shape, from the Hellenistic Greek word νάβλα for a Phoenician harp,[2][3] and was suggested by the encyclopedist William Robertson Smith in an 1870 letter to Peter Guthrie Tait.

The one published use of the word by Maxwell is in the title to his humorous Tyndallic Ode, which is dedicated to the "Chief Musician upon Nabla", that is, Tait.

William Thomson (Lord Kelvin) introduced the term to an American audience in an 1884 lecture;[2] the notes were published in Britain and the U.S. in 1904.

The name Nabla seems, therefore, ludicrously inefficient.Heaviside and Josiah Willard Gibbs (independently) are credited with the development of the version of vector calculus most popular today.

The influential 1901 text Vector Analysis, written by Edwin Bidwell Wilson and based on the lectures of Gibbs, advocates the name "del":[14]This symbolic operator ∇ was introduced by Sir W. R. Hamilton and is now in universal employment.

It has been found by experience that the monosyllable del is so short and easy to pronounce that even in complicated formulae in which ∇ occurs a number of times, no inconvenience to the speaker or listener arises from the repetition.

They were all originally studied in the context of the classical theory of electromagnetism, and contemporary university physics curricula typically treat the material using approximately the concepts and notation found in Gibbs and Wilson's Vector Analysis.

A symbol of the same form, though presumably not genealogically related, appears in other areas, e.g.: My dear Sir, The name I propose for ∇ is, as you will remember, Nabla...