Squintz Posted November 10, 2003 Posted November 10, 2003 I was once told that glass is not a solid but is a liquid. Is this true? I was told that that is the reason the large skyscrapers filled with glass windoes have to flip the glass 180 degrees because the gravity causes the glass to taper leaving the top side more narrow over time.
atinymonkey Posted November 10, 2003 Posted November 10, 2003 Yes, if you go to an old building with it's original glass (like a church) you can see the thickening at the bottom quite easily. My Grandmas lodge has glass that is only 90 years old, and it's obvious in that too. It's something that's more obvious if you wander round old buildings for time to time. My Grandmas lodge predates the creation of the United States, which is nice.
VendingMenace Posted November 10, 2003 Posted November 10, 2003 technically,glass is known as an amorphous solid. I think the viscousity is way to incredeibly high for people to feel that they could call it a liquid. ON the other hand it does flow. The reason that glass flows is that it lacks a definite crystal structure that is found in most solids. As such, all the glass molecules are randomly oriented towards eachother. Thus, glass has no regularity or form (hence, amorphous). Due to the lack of this form, the molecules in glass can slowly slide by eachother and when under a net force (such as gravity) they tend to all go in one direction, over time. That is why old glass is thicker at the top than the bottom. The amorphous form of glass is also why it is so dangerous when it breaks. Since there is no crystal lattice to break along (think diamonds) it just kinda breaks randomly and can (and does) form exremely sharp edges. So sharp that some of the edges are mere molecules thick. that is why broken glass is so sharp. Cool
swansont Posted November 10, 2003 Posted November 10, 2003 Glass doesn't flow. It's thicker at the bottom because it was installed that way - old glass wasn't necessarily of uniform thickness. urban legends page U Alberta page yet another site
YT2095 Posted November 10, 2003 Posted November 10, 2003 glass is indeed a liquid! as is bitumen (pitch). when either are "shattered" they will be razor sharp for a protracted length of time, but will eventualy become blunt, Pitch if suspended (undisturbed) will actualy drip roughly once every 10 years. yes Glass IS a liquid (hes quite right) and also an Ionic liquid too! that means it will conduct elec when in a liquid (in our time frame)state too
greg1917 Posted November 10, 2003 Posted November 10, 2003 Also, if you cool liquid glass there is a uniform line on the graph of of temperature against time. No plateau where the liquid -> solid conversion takes place due to latent heat being removed from he system. as such Its difficult to say glass is a solid in the strictest sense... this was probably covered in one of the sites swansont posted posted but im busy and dont have time to read em. will try to do so later.
Sayonara Posted November 10, 2003 Posted November 10, 2003 Since it shares dozens of properties with solids, and only 1 or 2 with liquids, I'm inclined to say "solid".
YT2095 Posted November 10, 2003 Posted November 10, 2003 sayo, technicaly you`re wrong, it IS a liquid
Sayonara Posted November 10, 2003 Posted November 10, 2003 I said I was "inclined to say". Notice how I avoided making absolute statements that might come back to bite me in the ass? It actually displays fluid properties, not liquid properties. If it's not a solid, then its next most appropriate categorisation should be as a fluid. Or are refined sugars and sand liquids too?
Squintz Posted November 10, 2003 Author Posted November 10, 2003 What is the definition of a fluid and what is the definition of a liquid as scientif terms. I always thought they were the same?
YT2095 Posted November 10, 2003 Posted November 10, 2003 well now would be a good time to put your computer experience and knowledge to the test on GOOGLE as stated in the post "Quiet"
Squintz Posted November 10, 2003 Author Posted November 10, 2003 That takes the fun out of using a forum also like someone said in another post. Of course i could look it up in google. In fact i can probably look everything that is talked about in this forum on google but the defeats the purpose of the forums I could use dictionary.com or i could use the encarta software i have installed on my PC also. and i could get an answer for myself but that would be to easy. I like reading multiple sources. So after i got an answer from you guys i would have look up the definitions and seen if your definition and the dictionarys definition were the same and reading 2 differnt definitions would give me twice the chance to understand what was being said. I get the feeling im not liked around here or something!
Dudde Posted November 10, 2003 Posted November 10, 2003 can we all say "amorphous" ? glass does flow, but today's glass flows at a rate of which you'd have to be even older than my mother to ever see the effects which I'm sure is explained with sayo's link, but I have homework to do so I'll read that later
Sayonara Posted November 10, 2003 Posted November 10, 2003 It's not my link - swansont posted it first. I reposted it because it was obviously not read.
Dudde Posted November 10, 2003 Posted November 10, 2003 o... well, replace sayo with swansont didn't see it
atinymonkey Posted November 11, 2003 Posted November 11, 2003 Dammit. Another thing I was taught at school that turns out to be hideous lies then. Alluvial silt is deposited by glaciation in valleys, who thought it would be funny to teach me that?
Duke Posted November 13, 2003 Posted November 13, 2003 Maybe it would be easier to say that there is a gradual transition between the state of a material. Solid-Liquid-Gas isn't efficient enough man. I say that glass is more solid than liquid but more liquid than your average solid.
VendingMenace Posted November 13, 2003 Posted November 13, 2003 well, generally speaking phase transitions are quite descrete. That is, solids are solids, liquids are liquids. And when something transitions from one to the other, it does it in one fell swoop. There is no incremental transtion as something moves more and more to a liquid. It is just a solid and then in the next instant, it is a liquid.
Dudde Posted November 14, 2003 Posted November 14, 2003 yes, glass shows a liquid state of displacement of molecules, yet the bonds are strong enough to be a solid this is known as amorphosity
Alarium Posted November 14, 2003 Posted November 14, 2003 Well, glass is technically a supercooled liquid. Amorphous means, "having no fixed form or shape," quoted from the Cambridge International Dictionary of English website. So, liquid is amorphous as well, yet there are amorphous solids such as clay. Glass does fit into that catagory. I guess it's a bit of an enigma to have it fit in both catagories. But, from the references that I've seen, they mainly classify it as a liquid.
Sayonara Posted November 14, 2003 Posted November 14, 2003 Oh for the love of god. Is glass called an "amorphous liquid"? NO. It's called an "amorphous solid", so-called because it's a solid. Clever, isn't it? It is NOT a supercooled liquid - this is an urban myth as documented quite clearly here in the testimony of many highly-educated experts in the field of amorphous and vitrine materials. Read the damned link people. Here in ancient and backwards Europialand we do actually have glass that is several centuries old, and no it does not change its shape in any way over the years. Get over it, move on, find something interesting to discuss. PS - even the American Society for Testing and Materials disagrees with you: ASTM (1996) "D4359-90: Standard Test Method for Determining Whether a Material Is a Liquid or a Solid." [excerpts] In: ASTM "Annual Book of ASTM Standards", Section 6, Vol 6.01, pp. 500-501. American Society for Testing and Materials, West Conshohocken, PA. ISBN 0803122705 [set] 0803123094 [section] 0803123108 [Volume]. 3. Summary of Test Method. The material under test is held at 100deg.F (38deg.C) in a tightly closed can. The lid is removed and the can inverted. The flow of the material from the can is observed to determine whether it is a solid or a liquid. 5. Apparatus. 5.1. Can, quart (1L), friction top with lid, diameter approximately 4'1/4 in (108 mm) height 4'3/4 in (120 mm) 5.2. Oven, maintained at temperature of 100deg.F (38deg.C) 5.3. Tripod or ring stand 5.4. Watchglass, tared 5.5. Stopwatch 5.6. Ruler. 9. Interpretation of results. 9.1. A material that flows a total of 2 in (50 mm) or less within 3 min is considered a solid. Otherwise it is considered a liquid.
swansont Posted November 14, 2003 Posted November 14, 2003 Sayonara³ said in post #23 :Oh for the love of god. ... Read the damned link people. Seconded.
Guest lunaeus Posted November 14, 2003 Posted November 14, 2003 So to kick a dead horse... Glass would be an amorphously liquid material. Being it is in a state of a readiness to flow. So not quite a fluid or flux material.
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