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From: lowj_ltd@uhura.cc.rochester.edu (John "Travis" Low)
Newsgroups: comp.text.tex,sci.lang,sci.math
Subject: Re: Can someone tell me what NABLA means?
Message-ID: <8987@ur-cc.UUCP>
Date: 18 Aug 90 03:28:17 GMT
References: <993@barsoom.nhh.no>
Organization: Univ. of Rochester, Computing Center
Lines: 24

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".  
>[...]
>So far, I've found that it's not a Greek or Hebrew letter (as I first
>thought it must be), and neither is it (I believe) of Phoenician or
>Egyptian origin.  If anyone can tell me why nabla is called nabla,
>I'll sleep better at night!  :-)  
>[...]

From my introductory calculus textbook, _Calculus_, by Howard Anton,
third edition, at the bottom of page 995:

"The symbol [insert nabla here] (read, "del") is an inverted delta. In
older books this symbol is sometimes called a "nabla" because of its
similarity in form to an ancient Hebrew ten-stringed harp of that name."

I attempted to verify this with some references I have around the house,
but I couldn't find anything. Sounds semi-plausible, though.

--Travis