# Light, Space, Time and the Trombone **URL:** \ **Category:** Factual Questions\ **Created:** [January 26, 2009, 1:11am UTC](https://boards.straightdope.com/t/light-space-time-and-the-trombone/482993 "2009-01-26T01:11:20Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Cartooniverse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cartooniverse/32/3084_2.png) [@Cartooniverse](https://boards.straightdope.com/u/Cartooniverse)\ **Post date:** [January 26, 2009, 1:11am UTC](https://boards.straightdope.com/t/light-space-time-and-the-trombone/482993/1 "2009-01-26T01:11:20Z")
Sitting there at a high school concert this afternoon. Trombone player standing 10 feet from me. Gets a fellah thinking. [Spacecurve](http://mysite.verizon.net/rogmios/sitebuildercontent/sitebuilderpictures/spacecurve.jpg) is usually depicted as something akin to this image. Your average trombone has a bell that looks [like this](http://upload.wikimedia.org/wikipedia/commons/thumb/4/40/Trombone.svg/700px-Trombone.svg.png), or [this](http://www.soundjunction.org/uploads/images/A2504_TromboneBell_198x161_1198.jpg). Remarkably similar. Is there something about that shape that is common for a good reason? Does sound amplify in a way similar to the way that scientists believe that space bends? I’m quite serious. I saw something that sure looked like something else. Is there an underlying elegance / commonality / reason for such a marked similarity? Cartooniverse ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [January 26, 2009, 2:05am UTC](https://boards.straightdope.com/t/light-space-time-and-the-trombone/482993/2 "2009-01-26T02:05:28Z")
There’s a reason trumpet (and trombne) bells are shaped the way they are – they make the output louder and affect the frequencies of the horn. There’s theory going back quite a ways on this: > **[Brass instrument (lip reed) acoustics: an introduction](http://www.phys.unsw.edu.au/jw/brassacoustics.html#bells)** > > How do brass instruments work? Brass instrument (lip reed) acoustics: an introduction. How does a trumpet work? How does a trombone work? > **[Yahoo | Mail, Weather, Search, Politics, News, Finance, Sports & Videos](https://www.yahoo.com/)** > > Latest news coverage, email, free stock quotes, live scores and video are just the beginning. Discover more every day at Yahoo! Gravity wells are inverse-square law forces with inverse-radius potentials. I don’t think musical instrument bels have these shapes. > **[Gravitational potential](https://en.wikipedia.org/wiki/Gravitational_well)** > > In classical mechanics, the gravitational potential is a scalar field associating with each point in space the work (energy transferred) per unit mass that would be needed to move an object to that point from a fixed reference point. It is analogous to the electric potential with mass playing the role of charge. The reference point, where the potential is zero, is by convention infinitely far away from any mass, resulting in a negative potential at any finite distance. > In mathematics, the gravit... Bottom line: It’s a coincidence. ---
**Author:** ![Cartooniverse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cartooniverse/32/3084_2.png) [@Cartooniverse](https://boards.straightdope.com/u/Cartooniverse)\ **Post date:** [January 29, 2009, 3:39am UTC](https://boards.straightdope.com/t/light-space-time-and-the-trombone/482993/3 "2009-01-29T03:39:51Z")
Okay then. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [January 29, 2009, 5:43pm UTC](https://boards.straightdope.com/t/light-space-time-and-the-trombone/482993/4 "2009-01-29T17:43:12Z")
Actually, I think it is less than a meaningless coincidence. Spacetime isn’t curved like the instrument bell. It is just that the instrument bell is a familiar three dimensional item that illustrates what curved two dimensional spacetime looks like. Whenever you talk about the curvature of spacetime, you kind of need an additional dimension to illustrate it with a physical model. But taken as a three dimensional item in flat or practically flat three dimensional space, the instrument bell isn’t illustrating anything and has no relevance in discussing curved three dimensional space. ---
**Author:** ![panamajack](https://avatars.discourse-cdn.com/v4/letter/p/47e85d/32.png) [@panamajack](https://boards.straightdope.com/u/panamajack)\ **Post date:** [January 29, 2009, 6:47pm UTC](https://boards.straightdope.com/t/light-space-time-and-the-trombone/482993/5 "2009-01-29T18:47:02Z")
> [@CalMeacham](#): > > Gravity wells are inverse-square law forces with inverse-radius potentials. I don’t think musical instrument **bels** have these shapes. Only if you play them loud enough.