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snoopies622
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The gradient, divergence, curl and Laplacian operators are so much a part of classical electromagnetism, I was wondering: what is their history? Who invented them? Newton? Laplace? Maxwell himself?
snoopies622 said:The gradient, divergence, curl and Laplacian operators are so much a part of classical electromagnetism, I was wondering: what is their history? Who invented them? Newton? Laplace? Maxwell himself?
VECTOR CALCULUS SYMBOLS
For vector analysis entries on the Words pages, see here for a list.
The vector differential operator, now written and called nabla or del, was introduced by William Rowan Hamilton (1805-1865). Hamilton wrote the operator as and it was P. G. Tait who established as the conventional symbol--see his An Elementary Treatise on Quaternions (1867). Tait was also responsible for establishing the term nabla. See NABLA on the Earliest Uses of Words page.
David Wilkins suggests that Hamilton may have used the nabla as a general purpose symbol or abbreviation for whatever operator he wanted to introduce at any time. In 1837 Hamilton used the nabla, in its modern orientation, as a symbol for any arbitrary function in Trans. R. Irish Acad. XVII. 236. (OED.) He used the nabla to signify a permutation operator in "On the Argument of Abel, respecting the Impossibility of expressing a Root of any General Equation above the Fourth Degree, by any finite Combination of Radicals and Rational Functions," Transactions of the Royal Irish Academy, 18 (1839), pp. 171-259.
Hamilton used the rotated nabla, i.e. , for the vector differential operator in the "Proceedings of the Royal Irish Academy" for the meeting of July 20, 1846. This paper appeared in volume 3 (1847), pp. 273-292. Hamilton also used the rotated nabla as the vector differential operator in "On Quaternions; or on a new System of Imaginaries in Algebra"; which he published in instalments in the Philosophical Magazine between 1844 and 1850. The relevant portion of the paper consists of articles 49-50, in the instalment which appeared in October 1847 in volume 31 (3rd series, 1847) of the Philosophical Magazine, pp. 278-283. A footnote in vol. 31, page 291, reads:
...
In that paper designed for Southampton the characteristic was written ; but this more common sign has been so often used with other meanings, that it seems desirable to abstain from appropriating it to the new signification here proposed.
Wilkins writes that "that paper" refers to an unpublished paper that Hamilton had prepared for a meeting of the British Association for the Advancement of Science, but which had been forwarded by mistake to Sir John Herschel's home address, not to the meeting itself in Southampton, and which therefore was not communicated at that meeting. The footnote indicates that Hamilton had originally intended to use the nabla symbol that is used today but then decided to rotate it to avoid confusion with other uses of the symbol.
The rotated form appears in Hamilton's magnum opus, the Lectures on Quaternions (1853, p. 610).
The del stuff, also known as the delta substance, has a long and complex history. It was first discovered by ancient civilizations along the Nile River in Egypt, where it was used for its healing properties. Throughout history, it has been used for various purposes, including as a pain reliever, anesthetic, and even as a currency in some cultures.
The del stuff is a naturally occurring substance that is produced by some plants and animals. It is extracted from the plant or animal through various methods, such as boiling or crushing. It can also be artificially synthesized in a laboratory setting.
The del stuff has many uses, both in traditional and modern medicine. It is commonly used as a pain reliever and anti-inflammatory agent. It has also been used to treat various ailments, such as headaches, stomachaches, and even toothaches. In addition, it has been used in cosmetic products and as a food preservative.
While the del stuff has many benefits, there are also potential risks associated with its use. Some people may experience allergic reactions or side effects from using it, such as nausea or dizziness. Additionally, there is a risk of contamination or impurities if the del stuff is not properly extracted or synthesized.
Yes, the del stuff is still used today in various forms. While it may not be as widely used as it was in ancient times, it is still a valuable substance in traditional and alternative medicine. There is also ongoing research to explore its potential uses in modern medicine and other industries.