# Liquid or Solid?

**URL:** <https://boards.straightdope.com/t/liquid-or-solid/512181>\
**Category:** Factual Questions\
**Created:** [October 1, 2009, 12:18am UTC](https://boards.straightdope.com/t/liquid-or-solid/512181 "2009-10-01T00:18:17Z")\
**Posts on this page:** 4\
**Page:** 2

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**Author:** ![Never\_Say\_Dice](https://avatars.discourse-cdn.com/v4/letter/n/ee59a6/32.png) [@Never\_Say\_Dice](https://boards.straightdope.com/u/Never_Say_Dice)\
**Post date:** [October 9, 2009, 9:54pm UTC](https://boards.straightdope.com/t/liquid-or-solid/512181/21 "2009-10-09T21:54:59Z")

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The concept of solid liquid gas only really applies to pure uniform molecules packed next to each other.

If you spray water steam onto a ski slope you get snow, which compacts and sags.  
Sure, the ice crystal is solid, but the entire structure is fluid, and can flow like avalanches and glaciers.

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**Author:** ![Tim\_R.Mortiss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tim_r.mortiss/32/142_2.png) [@Tim\_R.Mortiss](https://boards.straightdope.com/u/Tim_R.Mortiss)\
**Post date:** [October 10, 2009, 2:41pm UTC](https://boards.straightdope.com/t/liquid-or-solid/512181/22 "2009-10-10T14:41:34Z")

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[quote=“TheBori, post:11, topic:512181”]

> [@Tim\_R.Mortiss](#):
>
> My Ceramic Engineering professor …QUOTE]
> 
> Tim, Are you a Ceramic Engineer? If so, from which institute of higher education? Just curious…there aren’t many of us.
> 
> Rutgers University, BTW

No, sorry; I’m a mechanical engineer, University of Illinois. But I took a class in CE because I found it a fascinating area of study.

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**Author:** ![Bisected8](https://avatars.discourse-cdn.com/v4/letter/b/a4c791/32.png) [@Bisected8](https://boards.straightdope.com/u/Bisected8)\
**Post date:** [October 10, 2009, 4:07pm UTC](https://boards.straightdope.com/t/liquid-or-solid/512181/23 "2009-10-10T16:07:49Z")

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I recall that the definition I was given in school was that a solid had it’s particles held in place (albeit vibrating) and a liquid had them slide over each other (while they had sufficient energy to float freely in a gas).

From this, it could be said that the difference is fairly analogue (since it’s a matter of how much a solid can move before you decide that it’s a liquid).

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**Author:** ![scm1001](https://avatars.discourse-cdn.com/v4/letter/s/c4cdca/32.png) [@scm1001](https://boards.straightdope.com/u/scm1001)\
**Post date:** [October 11, 2009, 1:42am UTC](https://boards.straightdope.com/t/liquid-or-solid/512181/24 "2009-10-11T01:42:42Z")

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> [@Jinx](#):
>
> This led to questions like what is a stress ball?

A stress ball is an easilly deformable polymer foam. As such the polymer is a solid. However, the individual chains in the polymer are free to move locally, but held in rough place by crosslinks. So on a local molecular level it looks like a liquid, on a larger scale a solid. Without the crosslinks it would be free to flow (slowly) like a thick liquid or putty.

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