Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!rpi!bu.edu!snorkelwacker!bloom-beacon!eru!luth!sunic!tut!funic!santra!santra!thakulin From: thakulin@hila.hut.fi (Timo T Hakulinen) Newsgroups: comp.text.tex Subject: Re: Can someone tell me what NABLA means? Message-ID: Date: 17 Aug 90 22:57:31 GMT References: <993@barsoom.nhh.no> Sender: news@santra.uucp (Cnews - USENET news system) Followup-To: comp.text.tex Distribution: comp Organization: Helsinki University of Technology, Finland Lines: 30 In-Reply-To: tih@barsoom.nhh.no's message of 16 Aug 90 22:18:28 GMT In article <993@barsoom.nhh.no> tih@barsoom.nhh.no (Tom Ivar Helbekkmo) writes: > I've been trying to find out these past couple of days what the origin > of the name of the character/symbol "nabla" is. Nabla is used (as far > as I can gather) primarily in mathematics, and is a greek delta turned > upside down (i.e. a triangle standing on one of its points). In > mathematics, I'm told it's also called the "del operator". The name > nabla seems to be common in typesetting systems (TeX has it), and this > is what the character was called when it was part of ASCII. (The > position it held in the ASCII table is now occupied by '@'.) Nabla is an ancient musical instrument probably of semitic origin. It is supposedly like a Hebrew harp with 10-12 strings and its shape resembles that of an inverted delta. Thence the name of the mathematical symbol in question. For some reason nabla is not a very well known name for the del-operator, at least not on the new continent. In fact, The TeXbook is one of the few textbooks of U.S. origin that use it. In Finland it is commonly used among physicists and mathematicians. Timo [ A quiz from the leaflet of the local guild of chemistry students here: What does the physicist dream of? (choose the right alternative) a) nabla ]