tih@barsoom.nhh.no (Tom Ivar Helbekkmo) (08/17/90)
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 '@'.) 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! :-) Oh, and if you're reading this in sci.math, please respond by email, as I don't follow that group... -tih -- Tom Ivar Helbekkmo, NHH, Bergen, Norway. Telephone: +47-5-959205 tih@barsoom.nhh.no -- edb_tom@debet.nhh.no -- tih@macpost.nhh.no
thakulin@hila.hut.fi (Timo T Hakulinen) (08/18/90)
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 ]
jmu@uhccux.uhcc.Hawaii.Edu (James Unger) (08/18/90)
I believe that nabla is the Hebrew word for a lyre, which looked roughly triangular and was held apex downward. In vector analysis texts, nabla is typographically an inverted Greek upper-case delta--you can tell because of the different thicknesses of the three sides of the triangle. The Laplacian operator, which also pops up in vector analysis, looks like u.c. delta, but has equally thin lines on all three sides.
lowj_ltd@uhura.cc.rochester.edu (John "Travis" Low) (08/18/90)
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
jacob@gore.com (Jacob Gore) (08/18/90)
/ lowj_ltd@uhura.cc.rochester.edu (John "Travis" Low) / Aug 17, 1990 / > "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. From Davidson's _The Analytical Hebrew and Chaldee Lexicon_, under "n\'evel", meaning 3: "a musical instrument, perhaps so called from its shape [meanings 1 and 2 are "bottle" and "jar"--J]; generally considered to have been a kind of lute". (I don't see any forms that could be pronounced "nabla" or "navla" that can be used as nouns...) Jacob -- Jacob Gore Jacob@Gore.Com boulder!gore!jacob
cosell@bbn.com (Bernie Cosell) (08/19/90)
jacob@gore.com (Jacob Gore) writes: }/ lowj_ltd@uhura.cc.rochester.edu (John "Travis" Low) / Aug 17, 1990 / }> "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. }From Davidson's _The Analytical Hebrew and Chaldee Lexicon_, under }"n\'evel", meaning 3: "a musical instrument, perhaps so called from its }shape [meanings 1 and 2 are "bottle" and "jar"--J]; generally considered to }have been a kind of lute". (I don't see any forms that could be pronounced }"nabla" or "navla" that can be used as nouns...) That may be true, but a simple trip to a reasonable dictionary reaffirms the derivation [we can only speculate why folks don't START these kinds of inquiries with a look at a good dictionary...] Webster's third unabridged claims the Hebrew precursor is nebhel [with a hook over the 'e'] and that it is the Hebrew word for "harp". /Bernie\
nmartola@ra.abo.fi (Nils Martola EXG) (08/19/90)
In article <1380006@gore.com>, jacob@gore.com (Jacob Gore) writes: > / lowj_ltd@uhura.cc.rochester.edu (John "Travis" Low) / Aug 17, 1990 / > > "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. > > From Davidson's _The Analytical Hebrew and Chaldee Lexicon_, under > "n\'evel", meaning 3: "a musical instrument, perhaps so called from its > shape [meanings 1 and 2 are "bottle" and "jar"--J]; generally considered to > have been a kind of lute". (I don't see any forms that could be pronounced > "nabla" or "navla" that can be used as nouns...) > > Jacob > -- > Jacob Gore Jacob@Gore.Com boulder!gore!jacob The short summary tells it all; in the Hebrew Bible there are some occurrences of the word _nevel_, which refer to a musical instrument used in liturgic as well as in profane occasions (cf. for instance 1Sam 10,3; 2Sam 6,5; Amos 5,23; 6,5; Is 5,12; 14,11). It is commonly assumed that the instrument is a kind of harp or psalterion. The old Greek translation of the Hebrew Bible (the Septuagint) uses different words for _nevel_; in some instances (e.g. 1Sam 10,3; 2Sam 6,5) no translation at all is given, but a _transliteration_, that is NABLA. Nils Martola nmartola@ra.abo.fi (Internet)
heine@barsoom.nhh.no (Heine Rasmussen) (08/20/90)
]... The old Greek ]translation of the Hebrew Bible (the Septuagint) uses different words for ]_nevel_; in some instances (e.g. 1Sam 10,3; 2Sam 6,5) no translation ]at all is given, but a _transliteration_, that is NABLA. ]Nils Martola ]nmartola@ra.abo.fi (Internet) Correct. You also have the latin derivation nablium, "a kind of harp or lyre", used by Ovid somewhere. =========================================================================== Heine Rasmussen --- <sam_hr@debet.nhh.no> or <heine@barsoom.nhh.no> ___________________________________________________________________________ Address: | Phones: Center for Applied Research | Home: +47-5-102946 Norwegian School of Economics | Work: +47-5-959503 Breiviken 2 | N-5035 BERGEN-SANDVIKEN |
yaronf@huji.ac.il (Yaron Farber) (08/21/90)
lowj_ltd@uhura.cc.rochester.edu (John "Travis" Low) writes: >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). >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." >--Travis My Webster's 9th Collegiate wouldn't help, which is a shame, but indeed "nevel" is Modern Hebrew for harp (`b' and `v' are related in Semitic languages, including Hebrew) and this name also appears in the Bible. But I don't know how you can prove exactly what instrument it was. -- Yaron Farber TEL: +972-3-282520 BITNET: yaronf@HUJINIX CSNET & INTERNET: yaronf@mush.huji.ac.il Snail: 22 Hissin St., 64284 Tel Aviv, Israel