# Is glass a liquid, or a solid? **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [June 24, 2008, 12:59am UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996 "2008-06-24T00:59:41Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![FoieGrasIsEvil](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/foiegrasisevil/32/16638_2.png) [@FoieGrasIsEvil](https://boards.straightdope.com/u/FoieGrasIsEvil)\ **Post date:** [July 3, 2008, 12:51am UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/21 "2008-07-03T00:51:12Z")
[QUOTE=Chronos] I don’t get it. **Nobody ever asks “Is a carrot a vegetable, or a root?”** , or “Is lettuce a vegetable, or a leaf?”. But both of those questions have exactly the same structure as “Is a tomato a vegetable, or a fruit?”. For that matter, nobody ever seems to ask the vegetable/fruit question about peppers, cucumbers, eggplants, green beans, or any of the other fruit vegetables, either. It’s only ever tomatoes. [/QUOTE] Well silly, that’s because it’s a ROOT VEGETABLE! 🙂 But I feel your pain. **a little lower, Monica, please** ---
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [August 14, 2008, 6:28pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/22 "2008-08-14T18:28:07Z")
[Another recent article](http://www.nytimes.com/2008/07/29/science/29glass.html?_r=1&oref=slogin) to add to the collection. ---
**Author:** ![rowrrbazzle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rowrrbazzle/32/414_2.png) [@rowrrbazzle](https://boards.straightdope.com/u/rowrrbazzle)\ **Post date:** [August 14, 2008, 9:56pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/23 "2008-08-14T21:56:57Z")
[Quote=andros] Hmmm. I’ll accept the whoosh, but I think it’s a stretch. [/quote] [QUOTE=Contrapuntal] Only if there’s a man on base. [/QUOTE] Or it’s the seventh inning. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [October 25, 2017, 3:50pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/24 "2017-10-25T15:50:03Z")
Yet another scholarly article on the “is glass a liquid” debate. This time, the authors are introducing a technical distinction between a true solid and a “frozen liquid”: > **[Solid or liquid? Researcher proposes a new definition of glass](https://www.spacedaily.com/reports/Solid_or_liquid_Researcher_proposes_a_new_definition_of_glass_999.html)** > > Sao Paulo, Brazil (SPX) Oct 20, 2017 - > Is glass a solid or a liquid? This question, which has been vigorously discussed by specialists in the field for some decades, has just been answered anew: Glass is a non-equilibrium, non-crystalli ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [October 25, 2017, 5:01pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/25 "2017-10-25T17:01:22Z")
> [@Saint\_Cad](#): > > Then what is [pitch](http://www.physics.uq.edu.au/pitchdrop/pitchdrop.shtml)? Since the thread has be re-awakened, here’s the updated[live feed for the Pitch Drop Experiment](http://www.thetenthwatch.com/). The site asks you to register because it keeps track of the time you spend watching - and ranks you against other watchers. ---
**Author:** ![SCSimmons](https://avatars.discourse-cdn.com/v4/letter/s/e495f1/32.png) [@SCSimmons](https://boards.straightdope.com/u/SCSimmons)\ **Post date:** [October 25, 2017, 5:08pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/26 "2017-10-25T17:08:33Z")
Is there a site where I can watch a live video feed of paint drying instead? ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [October 25, 2017, 5:37pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/27 "2017-10-25T17:37:32Z")
It’s the internet, so probably. Most of my first google grab brought up what looked like static pictures labeled “Watching Paint Dry”. There were a couple of YouTube videos, about ten minutes long. Maybe this is a niche waiting to be filled. ---
**Author:** ![Kron](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kron/32/12444_2.png) [@Kron](https://boards.straightdope.com/u/Kron)\ **Post date:** [October 25, 2017, 6:16pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/28 "2017-10-25T18:16:46Z")
> [@SCSimmons](#): > > Is there a site where I can watch a live video feed of paint drying instead? Just snag a copy of [Paint Drying](http://www.imdb.com/title/tt5375100/), a film that the filmmaker made as a [protest against the BBFC](http://www.independent.co.uk/arts-entertainment/films/news/bbfc-declares-paint-drying-film-a-u-after-sitting-through-all-607-minutes-a6834671.html). ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [October 25, 2017, 7:38pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/29 "2017-10-25T19:38:58Z")
> [@WhyNot](#): > > While this may be oversimplifying when you get into higher levels of chemistry and physics, it’s certainly clear enough for an article written for laypeople. Okay, as a layperson, I’ll bite: are there combinations of temperature and pressure where glass is unarguably a solid? ---
**Author:** ![Powers](https://avatars.discourse-cdn.com/v4/letter/p/edb3f5/32.png) [@Powers](https://boards.straightdope.com/u/Powers)\ **Post date:** [October 25, 2017, 8:47pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/30 "2017-10-25T20:47:20Z")
How come no one ever asks if peanut butter is a solid or a liquid? Or Silly Putty? Or glue? Why is it always glass? =) It seems to me that the trichotomy of solid-liquid-gas we all learned in elementary school is really applicable primarily to substances composed of single elements or compounds. Solutions and colloids and other mixtures don’t always adhere to those strict categories. Powers &8^] ---
**Author:** ![Irishman](https://avatars.discourse-cdn.com/v4/letter/i/b487fb/32.png) [@Irishman](https://boards.straightdope.com/u/Irishman)\ **Post date:** [October 25, 2017, 9:24pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/31 "2017-10-25T21:24:59Z")
Is glass a solution or colloid? ---
**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:** [October 26, 2017, 12:03am UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/32 "2017-10-26T00:03:45Z")
There’s also a tremendous possible variety of fluids which are neither liquids nor gases. A liquid is a fluid whose density is constant. A gas is a fluid whose density is proportional to its pressure divided by its temperature. But there are many other possible formulas for density (called “equations of state”) for fluids, many of which are known in nature. Just, not typically under Earthly conditions. ---
**Author:** ![octopus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/octopus/32/3716_2.png) [@octopus](https://boards.straightdope.com/u/octopus)\ **Post date:** [October 26, 2017, 7:13am UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/33 "2017-10-26T07:13:54Z")
How can you melt glass if it’s not a solid? Does it cut your foot? Does it flow when pressure is applied to it? Now, I’ve always heard glass at room temperatures is an amorphous solid. ---
**Author:** ![Terminus\_Est](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/terminus_est/32/3087_2.png) [@Terminus\_Est](https://boards.straightdope.com/u/Terminus_Est)\ **Post date:** [October 26, 2017, 12:47pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/34 "2017-10-26T12:47:46Z")
> [@Kron](#): > > Just snag a copy of [Paint Drying](http://www.imdb.com/title/tt5375100/), a film that the filmmaker made as a [protest against the BBFC](http://www.independent.co.uk/arts-entertainment/films/news/bbfc-declares-paint-drying-film-a-u-after-sitting-through-all-607-minutes-a6834671.html). There’s also the [Corn Cam](http://www.corncamiowa.com/). Corn is in the grass family, so you can watch grass grow. ---
**Author:** ![Irishman](https://avatars.discourse-cdn.com/v4/letter/i/b487fb/32.png) [@Irishman](https://boards.straightdope.com/u/Irishman)\ **Post date:** [October 26, 2017, 1:47pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/35 "2017-10-26T13:47:42Z")
Powers, I do agree that the solid-liquid-gas trichotomy only applies to single substance materials - either elements or compounds. That is part of the definition. What is tricky is that glass appears to be a single substance, but doesn’t crystallize under normal conditions. I’m disturbed by this definition of a “frozen liquid”. It messes with the definitions of _frozen_ and _liquid_. Freezing, by definition, is the process of solidifying. Maybe they could call it a “hard liquid” vs “amorphous solid”. Or, if one really wants to get scientific on the matter, they could define a _new state of matter_ - “glass: a type of fluid distinct from liquid, gas, and plasma that is hard like a solid but has an amorphous structure rather than a crystalline one and deforms spontaneously over time and under minimal pressure less than gravity, and which transitions to a crystalline solid state over time.” Or whatever properties it has that keep them from calling it a solid. Side note: is that 1g gravity or the gravity of the material itself, because put enough steel together at it will deform under the strength of it’s own gravity - that’s why planets are not cubes (well, maybe not cubes, but cubular, kind of like the Earth is sort of spherical but has a lot of bumps and distortions due to spin and such). ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [October 26, 2017, 4:47pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/36 "2017-10-26T16:47:11Z")
**Irishman** , the authors acknowledge that there is a “glass transition temperature” which, as glass blowers are well familiar with, marks the point at which glass can practically be worked. I think what the authors were saying is that glass has no minimum force to deform- any force whatsoever will, however slowly, make it deform. Whereas a “true” solid has some finite point at which (barring quantum tunneling) it will maintain its shape forever. BTW: some threads on the meme that cathedral windows are old enough to show deformation- [Can you really bend glass bare-handed?](http://boards.straightdope.com/sdmb/showthread.php?t=720465) [Glass; what is it?](http://boards.straightdope.com/sdmb/showthread.php?p=11240955) [Myths you were taught in school](http://boards.straightdope.com/sdmb/showthread.php?t=339458) ---
**Author:** ![DSYoungEsq](https://avatars.discourse-cdn.com/v4/letter/d/c6cbf5/32.png) [@DSYoungEsq](https://boards.straightdope.com/u/DSYoungEsq)\ **Post date:** [October 26, 2017, 7:30pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/37 "2017-10-26T19:30:02Z")
> [@octopus](#): > > How can you melt glass if it’s not a solid? Does it cut your foot? Does it flow when pressure is applied to it? > Now, I’ve always heard glass at room temperatures is an amorphous solid. You might want to read up on the issue via the MANY threads we’ve had discussing it over the years… 😉 ---
**Author:** ![octopus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/octopus/32/3716_2.png) [@octopus](https://boards.straightdope.com/u/octopus)\ **Post date:** [October 26, 2017, 9:22pm UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/38 "2017-10-26T21:22:42Z")
> [@DSYoungEsq](#): > > You might want to read up on the issue via the MANY threads we’ve had discussing it over the years… 😉 I’ve read about it. But amorphous solids are still solid. > **[Phases of ice](https://en.wikipedia.org/wiki/Amorphous_ice)** > > The phases of ice are all possible states of matter for water as a solid. Currently, twenty one phases, including both crystalline and amorphous ices, have been observed at various densities. > Most liquids under increased pressure freeze at higher temperatures because the pressure helps to hold the molecules together. However, the strong hydrogen bonds in water make it different: for some pressures higher than 1 atm (0.10 MPa), water freezes at a temperature below 0 °C. Subjected to higher pressu... ---
**Author:** ![Balance](https://avatars.discourse-cdn.com/v4/letter/b/ccd318/32.png) [@Balance](https://boards.straightdope.com/u/Balance)\ **Post date:** [October 27, 2017, 2:13am UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/39 "2017-10-27T02:13:47Z")
> [@Lumpy](#): > > BTW: some threads on the meme that cathedral windows are old enough to show deformation- Some of those threads are old enough to show deformation. ---
**Author:** ![Siam\_Sam](https://avatars.discourse-cdn.com/v4/letter/s/d78d45/32.png) [@Siam\_Sam](https://boards.straightdope.com/u/Siam_Sam)\ **Post date:** [October 27, 2017, 5:34am UTC](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996/40 "2017-10-27T05:34:09Z")
One of my college profs told us glass was a liquid. Okay, he was a Geography professor. But he had us convinced that the glass in windows grew thicker toward the bottom and thinner at top due to “running.” [Previous page](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996.md?page=1) [Next page](https://boards.straightdope.com/t/is-glass-a-liquid-or-a-solid/453996.md?page=3)