On glass being liquid

[Munachi]

I just recently learned this (that glass is liquid) and most say I am not quite over it yet. I was told this is pretty much common knowledge, so I feel a bit cheated and wonder if I am the stupid one here... So I guess the reason for this post is that I am trying to find out whether it was really just me that didn't know. The other question is, would then, in theory, it be possible to walk through a (closed) window without breaking it, and how many thousands or millions of years it would take.

 

[logophile]

I remember feeling quite put out by this discovery, too. It was proven to me at the time and I believed it, but it took some getting used to.

As to your other question... well, when you put it that way I suppose it would be possible if you could figure out the correct speed.

 

[Liar]

I just recently learned this (that glass is liquid) and most say I am not quite over it yet. I was told this is pretty much common knowledge, so I feel a bit cheated and wonder if I am the stupid one here... So I guess the reason for this post is that I am trying to find out whether it was really just me that didn't know. The other question is, would then, in theory, it be possible to walk through a (closed) window without breaking it, and how many thousands or millions of years it would take.

Yes, no, and maybe. Whether glass is liquid or solid is a matter of semantics, it seems. Some say it's in a third state somewhere in-between. It could be a liquid with a high viscosity (thickness, basically). But it has different molecular structure than both ordinary liquids and solid material.

Maybe you have heard about old windows being thivker at the bottom than at the top? This is often used as an argument for saying that glass is liquid. But that has other explanations, in how those panes were manufactured.

Here's a pretty good article about it if you want to get gritty with popular science.

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

 

[LadyJeanne]

I felt that way when I found out "the" Smithsonian was a bunch of museums and not one giant museum, like the Louvre.

I'm still not over it.

 

[Munachi]

I remember feeling quite put out by this discovery, too. It was proven to me at the time and I believed it, but it took some getting used to.

As to your other question... well, when you put it that way I suppose it would be possible if you could figure out the correct speed.

One thing my brother and I were thinking about, to find this out, was what would happen if you just had some glass in a place where there is no danger of someone moving it, and a heavy piece of wood or similar leaning against it. That way, there should be the "right speed", shouldn't there? because it's just gravity working. Wonder if I should put that up and have my children and their children and their children etc. etc. check it for many generations, so one day they might see whether the piece of wood has moved a little bit deeper into the glass, and maybe finally through it. If then, there is a heaven, they could report back to me once they die. (and no, I am not drunk nor on any drugs, hehe.)

 

[Liar]

One thing my brother and I were thinking about, to find this out, was what would happen if you just had some glass in a place where there is no danger of someone moving it, and a heavy piece of wood or similar leaning against it. That way, there should be the "right speed", shouldn't there? because it's just gravity working. Wonder if I should put that up and have my children and their children and their children etc. etc. check it for many generations, so one day they might see whether the piece of wood has moved a little bit deeper into the glass, and maybe finally through it. If then, there is a heaven, they could report back to me once they die. (and no, I am not drunk nor on any drugs, hehe.)

If there's a heaven, I'm sure you could just ask God about it.

"Hey, yer Lordship, there's this thing that's been bugging me all my life... "

 

[Munachi]

Yes, no, and maybe. Whether glass is liquid or solid is a matter of semantics, it seems. Some say it's in a third state somewhere in-between. It could be a liquid with a high viscosity (thickness, basically). But it has different molecular structure than both ordinary liquids and solid material.

Maybe you have heard about old windows being thivker at the bottom than at the top? This is often used as an argument for saying that glass is liquid. But that has other explanations, in how those panes were manufactured.

Here's a pretty good article about it if you want to get gritty with popular science.

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

I heard that about the windows being thicker at the bottom, yes... Interesting what the article says, I have to tell my dad about this, as this was one of the things he told me...

As for the whole thing about supercooled liquids etc., that is interesting too... Another thing I was told is, that glass never - no matter what extreme temperatures - becomes solid or a gas...

What this all makes me wonder is, why chemistry and physics classes in school never tought me this. It is all quite interesting. Or maybe we learnt it and I just didn't listen...

 

[Guest]

I heard that about the windows being thicker at the bottom, yes... Interesting what the article says, I have to tell my dad about this, as this was one of the things he told me...

As for the whole thing about supercooled liquids etc., that is interesting too... Another thing I was told is, that glass never - no matter what extreme temperatures - becomes solid or a gas...

What this all makes me wonder is, why chemistry and physics classes in school never tought me this. It is all quite interesting. Or maybe we learnt it and I just didn't listen...

My husband is a science teacher. He says the matter is discussed in his physical science classes. In his classes, anyway.

 

[Munachi]

hm, here is another link someone just gave me, saying that glass doesn't flow... here...

 

[Liar]

My husband is a science teacher. He says the matter is discussed in his physical science classes. In his classes, anyway.

And he has not been enforced to read a statement about Intelligent Floating and referr the curious youngsters to 'Of Granite And Goo' yet?

 

[Guest]

And he has not been enforced to read a statement about Intelligent Floating and referr the curious youngsters to 'Of Granite And Goo' yet?

Not yet. Give our State Board of Educational Idiots a little more time . . .

 

[R. Richard]

As for the whole thing about supercooled liquids etc., that is interesting too... Another thing I was told is, that glass never - no matter what extreme temperatures - becomes solid or a gas...

What this all makes me wonder is, why chemistry and physics classes in school never tought me this. It is all quite interesting. Or maybe we learnt it and I just didn't listen...

There are gas phases in glass formation due to volcanic eruptions. The precise stages are not very well understood, but there are gas phases.

 

[fifty5]

Related item...

Another strange state is that of 'elastic liquids'. These bounce back if they are deformed suddenly - or tear if the stress is too great, too fast.

Wet cornflour is the commonest example. Next time you are using cornflour, add the water (or stock, etc.) slowly, then, as soon as there is enough water to make the flour into a stiff 'cream', drag your stirring tool (spoon, or whatever) quickly through the mixture - you'll find that it breaks, then the fragments slowly flow together again. I haven't heard how one could demonstrate the elasticity by getting some to bounce, but in theory it should...

I have seen another elastic liquid 'bounce'. I think it was some silicone or something. The demonstrator poured it from a big bottle, then when the slowly moving stream was several inches out of the bottle, he quickly snipped off most of the stream with some shears. The top of the stream 'bounced' back into the bottle, then started to creep out again...

Fun, ain't it?

 

[Stella_Omega]

Another strange state is that of 'elastic liquids'. These bounce back if they are deformed suddenly - or tear if the stress is too great, too fast.

Wet cornflour is the commonest example. Next time you are using cornflour, add the water (or stock, etc.) slowly, then, as soon as there is enough water to make the flour into a stiff 'cream', drag your stirring tool (spoon, or whatever) quickly through the mixture - you'll find that it breaks, then the fragments slowly flow together again. I haven't heard how one could demonstrate the elasticity by getting some to bounce, but in theory it should...

I have seen another elastic liquid 'bounce'. I think it was some silicone or something. The demonstrator poured it from a big bottle, then when the slowly moving stream was several inches out of the bottle, he quickly snipped off most of the stream with some shears. The top of the stream 'bounced' back into the bottle, then started to creep out again...

Fun, ain't it?

Colloids! Whee! Egg whites, cornstarch, quicksand, gack...
Try mixing cornstarch with only a little bit of water. still you get a very stiff substance.
You'll find you can pick it up in your fingers. As long as you keep pressure on it, it will stay pretty solid- but it will turn liquid around the edges of your fingers, and slime its way out. It used to keep me and my sister happy for hours- we didn't have a TV

 

[Munachi]

My husband is a science teacher. He says the matter is discussed in his physical science classes. In his classes, anyway.

well maybe my teachers did teach us... i wasn't particularly listening most of the time. especially after the teacher once walked to me while we were all writing something, looked at my then green hair, and said in a very loud, for all to hear, whisper "Aren't your parents just shocked by the way you look?"

I had some tutor classes at some point and that teacher was a nice and fun person, and i was amazed at times how interesting some of the things we learned were in fact...

 

[Munachi]

Another strange state is that of 'elastic liquids'. These bounce back if they are deformed suddenly - or tear if the stress is too great, too fast.

Wet cornflour is the commonest example. Next time you are using cornflour, add the water (or stock, etc.) slowly, then, as soon as there is enough water to make the flour into a stiff 'cream', drag your stirring tool (spoon, or whatever) quickly through the mixture - you'll find that it breaks, then the fragments slowly flow together again. I haven't heard how one could demonstrate the elasticity by getting some to bounce, but in theory it should...

I have seen another elastic liquid 'bounce'. I think it was some silicone or something. The demonstrator poured it from a big bottle, then when the slowly moving stream was several inches out of the bottle, he quickly snipped off most of the stream with some shears. The top of the stream 'bounced' back into the bottle, then started to creep out again...

Fun, ain't it?

i am not sure i fully understand this... cornflour, is that the stuff you make polenta of?

as for the bouncing, doesn't even water do this? when a faucet is just dropping, and you see the water slowly coming out, and in the end part falls down as a drop of water, and at least it looks like a little bit that was left behind goes up a bit into the faucet again before it forms a new drop?

 

[Munachi]

There are gas phases in glass formation due to volcanic eruptions. The precise stages are not very well understood, but there are gas phases.

hm, i did once by mistake throw a plastic bag into a volcano. maybe i should have thrown a glass instead, and then have followed it to see what happens to the glass... though of course it might still have taken a while for the volcano to erupt.

 

[Wildcard Ky]

My husband is a science teacher. He says the matter is discussed in his physical science classes. In his classes, anyway.

You're in Kansas. The only true answer is Glass is exactly what God intended it to be.

 

[Stella_Omega]

i am not sure i fully understand this... cornflour, is that the stuff you make polenta of?

as for the bouncing, doesn't even water do this? when a faucet is just dropping, and you see the water slowly coming out, and in the end part falls down as a drop of water, and at least it looks like a little bit that was left behind goes up a bit into the faucet again before it forms a new drop?

You want corn STARCH, not flour. The shape of the starch granules is what makes it work. The reason water drops hold together is a different mechanism called surface tension
http://exploratorium.edu/ronh/bubbles/sticky_water.html
My dad loves all this stuff

 

[dr_mabeuse]

In chemistry, a solid is something that has definite volume and definite shape. A liquid (the rarest state of matter in the universe) has definite volume but indefinite shape, and a gas had indefinite volume and indefinite shape. By this definition, glass is a solid.

Solids are of two types: either crystalline or amorphous. We all know what a crystal is, and in a crystaline solid, all the atoms or molecules are arranged in a specific, well-ordered way. Most inorganic subtances (those that don't contain carbon) exist as crystaline solids. A snowflake is a crystalline form of water, and the showflake's six-fold symmetry is due to the shape of the water molecule which is bent like a boomerang with an H-O-H angle of 103 degrees. That angle and the attraction betwen different molecules' H's and O's (hydrogen bonding) makes water molecules cluster in 6-member rings.

Crystals have definite melting points, which means that it stays the same until you reach it's melting point whereupon it all dissolved right there. (Ice is either water of ice. It never becomes pourable ice) Sharp melting point is one of the indicators of a substance's crystalinity.

There are a whole raft of different types of amorphous solids, everything from human flesh to plastic. The critical things about amorphous solids is that their atoms or molecules are not well-ordered with precisely defined locations. They're a jumbled mess. Because they have no internal structure, most of them will start to flow as their temperature rises, like plastic or tar. They can be thought of as very, very viscous (or thick) liquids.

Glass is an amorphous soild, a random arrangement of SiO2 molecules, and as such can be thought of as an extremely viscous liquid. It has no sharp melting point, and will begin to deform and flow at elevated temperature. Whether common windowglass shows any significant flow at common earth temperatures is currently under investigation. Wouldn't surprise me either way though.

There is a substance called "water glass", which is (if I recall correctly) sodium metabisilicate. It dissloves in water and forms a very viscous, kind of glassy solution, kind of like glass dissolved in water. It's cheap and fun and they used to put it in chemistry sets. As I recall you could paint stuff with it and let the water evaporate and you'd have this very delicate glass coating on the thing. Wouldn't stick though.

Glass is fasinating stuff and they can do amazing things with it. Lucky for us it's very inert and almost insoluble in every liquid except for hydrofluoric acid, which eats it up like water eats sugar.

Okay. Wake up. Lecture's over.

 

[R. Richard]

Crystals have definite melting points, which means that it stays the same until you reach it's melting point whereupon it all dissolved right there. (Ice is either water of ice. It never becomes pourable ice) Sharp melting point is one of the indicators of a substance's crystalinity.

Dr_M:
Close but not quite. A glacier is "pourable ice." OK, it does take a long time to pour, but pour it does.

 

[English Lady]

In chemistry, a solid is something that has definite volume and definite shape. A liquid (the rarest state of matter in the universe) has definite volume but indefinite shape, and a gas had indefinite volume and indefinite shape. By this definition, glass is a solid.

Solids are of two types: either crystalline or amorphous. We all know what a crystal is, and in a crystaline solid, all the atoms or molecules are arranged in a specific, well-ordered way. Most inorganic subtances (those that don't contain carbon) exist as crystaline solids. A snowflake is a crystalline form of water, and the showflake's six-fold symmetry is due to the shape of the water molecule which is bent like a boomerang with an H-O-H angle of 103 degrees. That angle and the attraction betwen different molecules' H's and O's (hydrogen bonding) makes water molecules cluster in 6-member rings.

Crystals have definite melting points, which means that it stays the same until you reach it's melting point whereupon it all dissolved right there. (Ice is either water of ice. It never becomes pourable ice) Sharp melting point is one of the indicators of a substance's crystalinity.

There are a whole raft of different types of amorphous solids, everything from human flesh to plastic. The critical things about amorphous solids is that their atoms or molecules are not well-ordered with precisely defined locations. They're a jumbled mess. Because they have no internal structure, most of them will start to flow as their temperature rises, like plastic or tar. They can be thought of as very, very viscous (or thick) liquids.

Glass is an amorphous soild, a random arrangement of SiO2 molecules, and as such can be thought of as an extremely viscous liquid. It has no sharp melting point, and will begin to deform and flow at elevated temperature. Whether common windowglass shows any significant flow at common earth temperatures is currently under investigation. Wouldn't surprise me either way though.

There is a substance called "water glass", which is (if I recall correctly) sodium metabisilicate. It dissloves in water and forms a very viscous, kind of glassy solution, kind of like glass dissolved in water. It's cheap and fun and they used to put it in chemistry sets. As I recall you could paint stuff with it and let the water evaporate and you'd have this very delicate glass coating on the thing. Wouldn't stick though.

Glass is fasinating stuff and they can do amazing things with it. Lucky for us it's very inert and almost insoluble in every liquid except for hydrofluoric acid, which eats it up like water eats sugar.

Okay. Wake up. Lecture's over.

*grinning* That got me all horny. I love intelligent men...I think I even understood a few of those words there too. (science was not a strong spot of mine, but somehow once I acheived 100% in a test!!!!!) Keep going

 

[zeb1094]

Dr_M:
Close but not quite. A glacier is "pourable ice." OK, it does take a long time to pour, but pour it does.

Well not quite, glaciers flow they don't 'pour'. The continental plates would then be pouring also, which they don't, they flow. Where two continental plates meet head on they flow up or one flows under the other.

A glacier does the same thing, they flow toward the least resitence when they reach the end of the flow it breaks off forming icebergs. A glacier doesn't pour out of a valley, it flows.

 

[NoJo]

"Is glass liquid?" is not really a scientific question. But, as people have posted here, it is a surprising and delightful substance (but I think water is even more suprising and delightful physically).

Words are liquid too. Matter doesn't care what you call it, and there are often no clear distinctions between states of matter.

Beware of applying a legalistic mind to science. In law, precise definitions are vital, and words are the tools of the trade. That's not how scientists look at the world, and if you try to be like that, you miss the complexity and subtleties of nature.

That's why scientists don't arbitrate in issues such as "when (precisely) does life begin in the womb?" -- they give evidence, but lawyers decide.

 

[Stella_Omega]

NIce point, Joe!

Glaciers don't "pour" at all- they move towards the colder side, when they move, and the mechanism is fairly simple on a flat plain, at least; The ice melts on the warmer side, moving that edge back. Rainwater, or atmospheric moisture, freezes on the colder side- moving that edge forward.

Sometimes, of course, gravity pulls a whole, huge, ice mass down a slope. Some of these masses are truly enormous, the size of a country. Then the melting back is overpowered by the reverse momentum of the slide, but the glacier is, in a way, moving backwards...