Is Glass a Liquid or a Solid?

[Lemmingspawn]

Glass is an amorphous solid that has been around in various forms for thousands of years and has been manufactured for human use since 12,000 BCE. The status of glass as a liquid, versus a solid, has been hotly debated. The short story is that glass is a supercooled liquid, meaning that it is rigid and static but does not change molecularly between melting and solidification into a desired shape. Glass is one the most versatile substances on Earth, used in many applications and in a wide variety of forms, from plain clear glass to tempered and tinted varieties, and so forth.

Glass occurs naturally when rocks high in silicates melt at high temperatures and cool before they can form a crystalline structure. Obsidian or volcanic glass is a well known example of naturally occurring glass, although it can also be formed by a lightning strike on a beach, which contains silicate-rich sand. Early forms of glass were probably rife with impurities and subject to cracking and other instability, but examples of glass beads, jars, and eating materials first appeared in ancient Egyptian culture.

When manufactured by humans, glass is a mixture of silica, soda, and lime. Other materials are sometimes added to the mixture to “frost” or cloud the glass or to add color. The elements of glass are heated to 1800° Fahrenheit (982° Celsius). The resulting fused liquid can be poured into molds or blown into various shapes, and when cooled, glass is a strong, minimally conducting substance that will not interact with materials stored inside. As a result, glass is frequently used in scientific laboratories to minimize inadvertent chemical reactions and to insulate power lines.

Silica is found in a wide variety of natural sources, including, most commonly, sand. Sodium carbonate, or soda, is used to lower the fusion point of silica, making glass light and workable. Soda is called a flux, because it brings the melting point of the mixture down. Lime is ground from limestone and makes the mixture more viscous, as well as making the glass less susceptible to the erosive qualities of water and acids.

Glass is a strange substance, defying easy scientific categorization. It is not a solid, not a gas, and not quite a liquid either. Generally, it is classified as a rigid liquid, maintaining liquid properties while acting like a solid. Heat can return the glass to a liquid and workable form, making it easy to reuse and recycle.

Glass is a favored material for a lot of reasons. It resists chemical interactions, it is easy to recycle, it does not leach chemicals like plastics do, and it can withstand extremes of heat and cold, although not at the same time. Tempered or safety glass is used in a wide variety of applications, and virtually all consumers use many forms of glass daily.

From here:

http://www.wisegeek.com/what-is-glass.htm

 

[atacam]

I disagree with that last scentance. Did anyone see Grand designs live on Tuesday?

They had a small room made out of glass, and the guy sat inside with shorts and t shirt on. They heated the room upto 20 degrees C, and cooled the outside to -43 degrees C. The glass did eventually crack, but later it was found to have been the aluminium frame that buckled making it crack.

Just a bit of useless info, not everything you read on the net is true.lol

 

[Shawn R. L.]

Originally posted by Einion

Originally posted by Shawn R. L.
Same for balsa wood....technically it\'s a hardwood....................right.lol

Yeah, but the hardwood/softwood thing is not about hardness, they\'re just unfortunate holdovers from the original origins of the terms

Einion

Right. I believe that no matter the \'hardness\' of a wood, what determines it to be hardwood or softwood is the shape of the leaves - broad leaved, hardwood ----- needle leaved, softwood.

 

[Infidel Castro]

Hey guys, let\'s get molecular. Wooooo! I\'m tripping out maaaan!

It\'s interesting stuff what I\'ve just read here, by the way. I\'m not going to lose any sleep over it though.

 

[freakinacage]

Originally posted by reverend
Hey guys, let\'s get molecular. Wooooo! I\'m tripping out maaaan!

It\'s interesting stuff what I\'ve just read here, by the way. I\'m not going to lose any sleep over it though.

yes you will cos i will go outside your house and shout obsenties, again

 

[Infidel Castro]

The last time you did that the glass was very embarrassed. It still hasn\'t quite recovered. No matter whether glass be liquid or solid, it\'s prudish if nothing else!

 

[Einion]

Originally posted by veggiemanuk

Originally posted by eastman
When assembling window panes using glass of unequal thickness, the thickest part is placed at the bottom to make it easier to assemble.

But how do you explain a 100% correct instalation then? This is millions of windows we are talking about here. How come none have been put in the wrong way around?

There have been, apparently. I\'m just taking what I read the other day at face value, but:
\"Occasionally such glass has been found thinner side down or on either side of the window\'s edge, as would be caused by carelessness at the time of installation.\"

That\'s from the Wikipedia entry. And this part is pretty compelling also:
\"If medieval glass has flowed perceptibly, then ancient Roman and Egyptian objects should have flowed proportionately more — but this is not observed.\"

And if this is correct (I sooo need to have this verified) then it\'s conclusive I think:
\"There are many examples of centuries-old glass shelving which has not bent, even though it is under much higher stress from gravitational loads than vertical window glass.\"

Einion

 

[sg2009]

???????????????????????????????????????

im confused ???

cant it be both

sam

 

[Necroghast]

Originally posted by airhead

Originally posted by skeeve
Neither. Glass is the third state. From a casual observer point of view it is \"solid\" but on the molecular level glass doesn\'t have ordered microcrystalic structure.

Anyway, the linky is bellow

http://math.ucr.edu/home/baez/physics/General/Glass/glass.html

Ding-ding-ding.

Glass has no crystaline structure - therefore it is not a solid. Ice has a crystaline structre as does every other solid. Glass is an extreemly viscus liquid.

& Mike, most bullet-resistant is not glass, but acrylic. One of the leading manufacturers brings his product to a major shoot each year just to gather info.

not every solid will have a crystaline structure. (crystal lattice) only some ionic compounds. an example being salt, an ionic compund of one sodium and one chlorine. according to my chemistry teacher father, glass is an amorphous solid. its silcon dioxide or more rarely silicon tetraoxide.