Glass- a solid or liquid?

Recently, the question was posed in another thread as to whether glass was a liquid or solid. With all honesty, my first answer to the question was, "Well of course it's a liquid. Haven't you seen really old glass window panes? They get thicker at the bottom over time." But wishing to give the other posters the courtesy of reading the articles they cited before blasting them with my great knowledge, I began to develop a strange sensation in mind. It was doubt. Quickly, I began my own independent search for an answer to this question.

My first stop lead me here. A stop off at the University of California- Riverside math department. My curiosity was not satisfactorily answered because the Conclusin of the article stated:

There is no clear answer to the question "Is glass solid or liquid?". In terms of molecular dynamics and thermodynamics it is possible to justify various different views that it is a highly viscous liquid, an amorphous solid, or simply that glass is another state of matter which is neither liquid nor solid. The difference is semantic. In terms of its material properties we can do little better. There is no clear definition of the distinction between solids and highly viscous liquids. All such phases or states of matter are idealisations of real material properties. Nevertheless, from a more common sense point of view, glass should be considered a solid since it is rigid according to every day experience. The use of the term "supercooled liquid" to describe glass still persists, but is considered by many to be an unfortunate misnomer that should be avoided. In any case, claims that glass panes in old windows have deformed due to glass flow have never been substantiated. Examples of Roman glassware and calculations based on measurements of glass visco-properties indicate that these claims cannot be true. The observed features are more easily explained as a result of the imperfect methods used to make glass window panes before the float glass process was invented.

As you can see highlighted above, this was much too ambiguous a staement to swallow and keep down if I wanted a definative answer.

Leaving academia for a bit I went to a glass manufacturer as a source. Ah, a source that takes a side! I especially enjoyed the use of the term "horsepucky." It made me feel like a kid again!

With finally finding a source that didn't mind making up it's mind and my curiousity reaching levels it knew only in childhood, I sought out more sources to evaluate.

Next I found a site stating with absolute certainty that glass was indeed a liquid. It listed all the old arguements I had heard in the past, but I had to wonder, who put up this page and what are their reasons for it? Backtracking the site to it's main page, I came to a rather biased decision to disregard this source entirely. I know, I know they say don't judge a book by its cover, but when the author's picture on the index page shows her with orangish-pink hair wearing platform shoes, and dressed like a reject from the "punk" era, I really cannot take the information seriously (at least without direct communication with the person in question).

Another vote for glass as an amorphous solid, led me to the University of Nebraska at Lincoln. Which gave the explaination that the glass as liquid folks were misquoting German Physicist Gustav Tamman.

And another site for amorphoussolid, which describes how the old arguments of glass windows with striations are often used as evidence of glass as a liquid are(cont)

(cont. from above) incorrect.

I would greatly appreciate all comments and any additional evidence that can be added to this question. If you happen to be an orangish-pink haired woman wearing platform shoes named Zyra, then you're comments are welcome, too.

To my knowledge, glass is nothing more than a liquid with sand in it... Although this is not something that I have studied extensively,but that has always been my impression. Of course the liquid becomes a "solid" through chemical processes and such. However, at base level, glass is nothing more than a liquid.

[edit on 16-12-2006 by SpeakerofTruth]

Well, my name is not Zyra, and though my haircolor once used to be called "carrot" it's a long time ago, so I hope you can trust me nevertheless. By the way what's wrong with pink-haired females wearing platform shoes?

Well back to topic. I was on that thread in the heated shattering of glass last night, and let me say I didn't gain further in wisdom. But doubt was seeded in my mind ...like it now is in yours I get the feeling of.

First the state of any matter is relative. Take ice, it's a true crystaline solid - as long as you keep it cold enough - but wil eventually turn into a liquid, unless you happen to be in the Arctic. When you put in the kettle for tea and you forget it, it becomes gas. Should gravity for some reason go berserk and its force thousandfold it will turn into plasma.

Same goes with any gas, pressurize it and you have a liquid and if you cool it enough it gets solid. And glass is somewhere between at the normal temperature by which we operate. Come to think about it, I've never heard about "glass gas" though.

But what I learned - and quite frankly shocked me a bit last night - was that it's without form, shapeless, deformed, as the definition for 'amorphous' goes. That it is combined with 'solid' makes it a semantic contradiction!! I guess it's an attempt to make everybody happy... or maybe it some political correctness observed in the world of physics. But imagine a shapeless solid! Not easy.

Therefore I stick to my childhood learning which says - or rather my old teacher of physics said - it's a liquid, very slow and very thick. He was a really nice guy. His most used phrase was:
"The experiment must be declared not succesful".

As a liquid I think glass is rather succesful. As a solid it is pretty fragile though. Still you can reinforce it to a degree it becomes bullet proof. But I think it involves combining it with non-amorphous materials. You can't have a bullet proof liquid... of can you??!

Originally posted by khunmoon
As a liquid I think glass is rather succesful. As a solid it is pretty fragile though. Still you can reinforce it to a degree it becomes bullet proof. But I think it involves combining it with non-amorphous materials. You can't have a bullet proof liquid... of can you??!

According to new advancements in bulletproof technology, it is possible. It's called Liquid Armor, and it can not only withstand the impact of an assault rifle, but also that of a knife.

Back in the day, it was called a super-cooled liquid.

Speaking in terms of it's proporities, Technically glass is a super-cooled liquid. While it seems solid to the touch, it's atoms are free moving like those of a liquid.

So what you have is: A fragile Liquid that can contain outer liquids and has the world's Highest Surface Tension! What a strange substance indeed!

Tim

Thank you all for your interest in joining this thread and sharing with us all. Honestly, I wasn't expecting anymore than 2 people at maximum to post anything. Impreza, you beat me to the recent development of "Liquid Armor" as I have either read about somewhere here or seen it on the History Channel's "Modern Marvels." I can't remember which exactly. Back to amorphous solids! This has to be the most ambiguous-sounding term in all of thermodynamics. I did a search and came up with the following results: The everpopular and highly dubious Wikipedia, University of Tennessee Memphis (on their physical pharmacy page), Purdue University's Chemistry Glossary (and apparently home the one line answer), and McGraw-Hill Encyclopedia of Science & Technology Online( a preview of the answer, but I think it's mostly there). Basically it comes down to terms of viscosity, or the resistance of a material to change form. I don't know exactly where the line is drawn on how viscosity needs to be to declared a solid, but from my understanding glass is above the standard. I'll try to find out for sure what the specifics are, but might not get it posted tonight.

[edit on 12/17/2006 by PapaHomer]

Originally posted by Ghost01
So what you have is: A fragile Liquid that can contain outer liquids and has the world's Highest Surface Tension! What a strange substance indeed!

Tim

Actually in Materials Science, Glass is considered an Amorphous Solid. Add a bit more heat and it becomes a Highly Viscous Liquid like Pitch.

[edit on 17-12-2006 by sardion2000]

From what I've been taught by professors in chemistry and materials...glass is an extremely vicious liquid. This can be seen on old churches - windows kind of look melted, almost.

Originally posted by T_Jesus
From what I've been taught by professors in chemistry and materials...glass is an extremely vicious liquid. This can be seen on old churches - windows kind of look melted, almost.

That's really interesting. My chem professor classifies it as a Amorphous Solid due to the high surface tension.

[edit on 17-12-2006 by sardion2000]

Originally posted by PapaHomer

...wishing to give the other posters the courtesy of reading the articles they cited before blasting them with my great knowledge, I began to develop a strange sensation in mind. It was doubt. ...

Thank you. Needed that.

My comment - When it comes to nanoparticles - and nano-organisms - glass is a liquid medium. The little suckers just swim right through it.

For what it's worth.




ed to add wd

[edit on 17-12-2006 by soficrow]

and nano-organisms - glass is a liquid medium. The little suckers just swim right through it.

You mean proteans?

Originally posted by sardion2000
Actually in Materials Science, Glass is considered an Amorphous Solid.
[edit on 17-12-2006 by sardion2000]

OK! that works for me. An Amorphous Solid it is!

Tim

Originally posted by sardion2000

and nano-organisms - glass is a liquid medium. The little suckers just swim right through it.

You mean proteans?

But actually, no I didn't.

Glass can't contain nano-scale organisms - they're small enough to move through the spaces. As I recall, the glass needs a diamond coat to keep them in.



added phrase for clarity

[edit on 17-12-2006 by soficrow]

Glass- a solid or liquid?

It's liquid.

What is a solid? What is a liquid? Do such states Exist? Yes and No.

Yes they Exist in the reality of the illusion of the finite by perceiving states of Being as they currently appear in the illusion of temporary time.

No, they do Not Exist in the Eternal reality where all is considered energy and has Not only the potential to Be both solid and liquid at some time, yet will Be and is solid and liquid at some time in its Eternal Existence; Everything is energy.

Thus Everything is Everything, concluding that Everything Exists both solidly and liquidly. Energy is Eternally and Outfinitely interconnected, Everything is energy and at some time will take the form of another "state" of Existence. No new energy can be created or destroyed, it is a constant transformation of states of the temporary; Everything Eternally Exists as Everything: The consciousness of the Unified Field.

Energy has No beginning and No ending and it has Existed as Every form imaginable. All is Energy. Existence is Eternal; energy is Eternal

[edit on 17-12-2006 by LastOutfiniteVoiceEternal]

Originally posted by soficrow
[My comment - When it comes to nanoparticles - and nano-organisms - glass is a liquid medium. The little suckers just swim right through it.
[edit on 17-12-2006 by soficrow]

Hi crow, thanks for joining the discussion. Which nano-organisms are you referring to? Do you have a link you can provide? Just curious because I would like to further my reading.

BTW, so far I have not found any source so far that lists how hi the viscosity of a substance needs to be for it to be considered a solid. Anyone out there still have a thermodynamics textbook or materials science (looking at sardion2000) book that might have the info?

LastOutfiniteVoiceEternal, I don't believe the poster was looking for a philosophical answer.

Sardion - most of the time it depends on who you ask, but technically it is a liquid.

Originally posted by PapaHomer

Originally posted by soficrow
When it comes to nanoparticles - and nano-organisms - glass is a liquid medium. The little suckers just swim right through it.

Hi crow, thanks for joining the discussion. Which nano-organisms are you referring to? Do you have a link you can provide?

Hey - thanks. Glad to be here.

Did a quick search for an overview, good keywords btw: nano-organisms, Nanorobotics, Molecular Motors, Nanomachines, Nanodevices, Nanomotors, Bionanotechnology - also nano-bio-bots

PDF with pics: PROTEIN BASED NANOROBOTIC ELEMENTS AND MACHINES

The biological elements will be used to fabricate robotic systems. A vision of a nano-organism: carbon nanotubes form the main body; peptide limbs can be used for locomotion and object manipulation, a biomolecular motor located at the head can propel the device in various environments.

***

Nanorobotics

Nano-robots are controllable machines at the nano (10 -9) meter or molecular scale that are composed of nano-scale components. With the modern scientific capabilities, it has become possible to attempt the creation of nanorobotic devices and interface them with the macro world for control. There are countless such machines that exist in nature and there is an opportunity to build more of them by mimicking nature. Even if the field of nanorobotics is fundamentally different than that of macro robots due to the differences in scale and material, there are many similarities in design and
control techniques that eventually could be projected and applied. A roadmap towards the progression of this field is proposed and some design concept and philosophies are illustrated. Two types of control mechanisms are given with examples and further hybrid mechanisms are proposed. There are many applications for nanorobotic systems and its biggest impact would be
in the area of medicine.

MORE:

Sorry - can't get the scholar link to work. ...Just search this:
Nanorobotics OR "Molecular Motors" OR Nanomachines OR Nanodevices OR Nanomotors OR Bionanotechnology OR nano-bio-bots

Google Pop


Also see:

Prey, by Michael Crichton
Excellent description of nano-organisms, ethics review, in fictional context.


tried to fix link


[edit on 18-12-2006 by soficrow]