# Physicists, what's this symbol? **URL:** \ **Category:** Factual Questions\ **Created:** [December 14, 2014, 3:08am UTC](https://boards.straightdope.com/t/physicists-whats-this-symbol/707180 "2014-12-14T03:08:27Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![coffeecat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/coffeecat/32/3405_2.png) [@coffeecat](https://boards.straightdope.com/u/coffeecat)\ **Post date:** [December 14, 2014, 3:08am UTC](https://boards.straightdope.com/t/physicists-whats-this-symbol/707180/1 "2014-12-14T03:08:27Z")
In [this equation,](http://users.rcn.com/brucezohn/eq.png) to the left of the equals sign, just after the delta. Does it have a name or a unicode number? I’ve never seen it before. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 14, 2014, 3:16am UTC](https://boards.straightdope.com/t/physicists-whats-this-symbol/707180/2 "2014-12-14T03:16:28Z")
I have no idea. What’s the context? I’m guessing that that’s from a scan of an old journal paper. The equation also looks odd in that there are some really obvious simplifications on the right side, such that I’m not sure why it would be written that way. ---
**Author:** ![rbroome](https://avatars.discourse-cdn.com/v4/letter/r/838e76/32.png) [@rbroome](https://boards.straightdope.com/u/rbroome)\ **Post date:** [December 14, 2014, 3:27am UTC](https://boards.straightdope.com/t/physicists-whats-this-symbol/707180/3 "2014-12-14T03:27:53Z")
> [@coffeecat](#): > > In [this equation,](http://users.rcn.com/brucezohn/eq.png) to the left of the equals sign, just after the delta. Does it have a name or a unicode number? I’ve never seen it before. when I first saw the symbol, it looked like a pi symbol in some fancy font. Not sure though. But that is my guess. ---
**Author:** ![coffeecat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/coffeecat/32/3405_2.png) [@coffeecat](https://boards.straightdope.com/u/coffeecat)\ **Post date:** [December 14, 2014, 3:32am UTC](https://boards.straightdope.com/t/physicists-whats-this-symbol/707180/4 "2014-12-14T03:32:31Z")
> [@Chronos](#): > > I have no idea. What’s the context? I’m guessing that that’s from a scan of an old journal paper. It’s from the Feynman Lectures. It’s the number of modes of photons or EM waves in a box. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [December 14, 2014, 3:39am UTC](https://boards.straightdope.com/t/physicists-whats-this-symbol/707180/5 "2014-12-14T03:39:05Z")
That is Y from the [Fraktur](http://en.wikipedia.org/wiki/Fraktur) font - maybe represented as gamma. I have seen it used in old texbooks for engineers ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [December 14, 2014, 3:42am UTC](https://boards.straightdope.com/t/physicists-whats-this-symbol/707180/6 "2014-12-14T03:42:48Z")
It’s “N” in a font called Fraktur. I have no idea what it means. ---
**Author:** ![JWT\_Kottekoe](https://avatars.discourse-cdn.com/v4/letter/j/3ec8ea/32.png) [@JWT\_Kottekoe](https://boards.straightdope.com/u/JWT_Kottekoe)\ **Post date:** [December 14, 2014, 3:44am UTC](https://boards.straightdope.com/t/physicists-whats-this-symbol/707180/7 "2014-12-14T03:44:54Z")
I believe it is a script N, i.e. the letter N in a fancy script font. Script letters show up from time to time in physics equations and N is sometimes used for the density of states, as in this case. ---
**Author:** ![coffeecat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/coffeecat/32/3405_2.png) [@coffeecat](https://boards.straightdope.com/u/coffeecat)\ **Post date:** [December 14, 2014, 3:47am UTC](https://boards.straightdope.com/t/physicists-whats-this-symbol/707180/8 "2014-12-14T03:47:37Z")
Thanks. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [December 14, 2014, 3:47am UTC](https://boards.straightdope.com/t/physicists-whats-this-symbol/707180/9 "2014-12-14T03:47:47Z")
No, it’s an “N” in Fraktur, an oldstyle German font. Fraktur is not a script typeface. ---
**Author:** ![JWT\_Kottekoe](https://avatars.discourse-cdn.com/v4/letter/j/3ec8ea/32.png) [@JWT\_Kottekoe](https://boards.straightdope.com/u/JWT_Kottekoe)\ **Post date:** [December 14, 2014, 10:23pm UTC](https://boards.straightdope.com/t/physicists-whats-this-symbol/707180/10 "2014-12-14T22:23:50Z")
> [@panache45](#): > > No, it’s an “N” in Fraktur, an oldstyle German font. Fraktur is not a script typeface. Thanks. I didn’t realize that it was Fraktur. It was always called “script N” when I encountered it in physics classes. I will note, however, that, when I took high-school German in the USA, Fraktur was called “German Script.” ---
**Author:** ![iljitsch](https://avatars.discourse-cdn.com/v4/letter/i/77aa72/32.png) [@iljitsch](https://boards.straightdope.com/u/iljitsch)\ **Post date:** [December 14, 2014, 10:38pm UTC](https://boards.straightdope.com/t/physicists-whats-this-symbol/707180/11 "2014-12-14T22:38:07Z")
Isn’t math great? If you don’t already know what something means there is no way to figure it out. ---
**Author:** ![Simplicio](https://avatars.discourse-cdn.com/v4/letter/s/c37758/32.png) [@Simplicio](https://boards.straightdope.com/u/Simplicio)\ **Post date:** [December 14, 2014, 10:41pm UTC](https://boards.straightdope.com/t/physicists-whats-this-symbol/707180/12 "2014-12-14T22:41:17Z")
> [@iljitsch](#): > > Isn’t math great? If you don’t already know what something means there is no way to figure it out. The OP knew what it meant. He’s just asking the name of the glyph.