is a glass liquid or solid?????

Question

glass is a liquid
it is so viscous that you think it's a solid
but when many years pass, you'll see that the lower part of the glass is much thicker than the upper part because it will take manyyears to flow........
thanks..........

Answer 1

Let me put this question to bed forever.

This is, as they say, an old wives tale. Glass is a non-crystalline solid in that its atomic structure is aperiodic (without order) however - IT IS A SOLID. Glass consists of mostly covalent coordinated tetrahedron with a yield strength of 5GPa. The resounding amount of research done most notably by Zanotto and Gupta estimate the viscosity of glass at room temperature to be on the order of 10^42 P meaning the time for any dimensional variations would be about 10^23 years! No one makes the claim that metals flow and yet the atoms of any metal are not rigidly bonded as with a glass. Way back when, flat glass was made by spinning from a central location. Simple centrifical force resulted in the outer edge of the glass being thicker.

We glass scientists don't help the cause by refering to some glasses as super-cooled liquids and glass transition temperatures but I assusre you that not only does glass not flow at room temperature, but its theoretical strength is higher than any other solid known to man.

I have a Ph.D. in glass science and I can assure you this is a "resolved question" but one we often find ourselves answering.

Answer 2

Glasses are amorphous solids. There is a fundamental structural divide between amorphous solids (including glasses) and crystalline solids. Structurally, glasses are similar to liquids, but that doesn't mean they are liquid. It is possible that the "glass is a liquid" urban legend originated with a misreading of a German treatise on glass thermodynamics.

Answer 3

Glass is a very cold liquid in some senses: it's composition is not crystaline but amorphic. However, the story about it flowing is hokum.

Old glass was produced by - well - old methods. Rather than being rolled as it is today, it was pressed or drawn, the latter being a common process; it resulted in ripples and air bubbles in the finished product. Perhaps that's why this idea started.

Answer 4

You're the victim of a common myth. Glass will flow at room temperatures, but only imperceptibly.

What you're seeing in those old-time windowpanes is window glass that was made with an old process. They'd take a huge bubble of glass, pull it out to form a cylinder, cut the cylinder so the walls laid flat, and cut the panes of glass out of that. The result was glass that was transparent, but pretty wavy.

Builders would install these glass panes so that the waviness was horizontal and thus less noticeable as you walked past while looking out the window. This is why the glass seems to be thicker on the bottom. But it was always like that.

Anyone who wanted flat, non-wavy glass back then had to purchase 'plate glass,' which was ground and polished flat at the factory. They'd use it for store windows and, sometimes, windows in fancy houses. Nowadays, we have a process known as 'float glass' that gives us glass that's flat as plate glass, and it's also quite inexpensive.

Glass at room temperature is a solid, but it's a non-crystalline solid, so some old-time chemists used to classify it as a liquid, or solidified liquid. That's just confusing: it's a solid. In fact, non-crystalline substances that resemble glass are themselves called 'glasses.' I believe that taffy, the candy, is one of these.

Answer 5

could it be that they may have made the glass that way? Everything can be a liquid or a solid or a gas,
it just depends on what temperature it is @.. ofcourse glass is a liquid.. thats just not the temperature i normally drink out of one @. if it was in a VERY slow moving liquid state @ room temperature, wouldnt even a small increase in the glasses temperature speed up the process.. or wouldnt the sides dip in or flex or wouldnt the walls eventually sag one way or another... if its a liquid.. it moves too dang slow for me to care.

Answer 6

Depends on whether you are a polymer chemist or just a plain old joe. Actually, glass is a liquid since it flows in response to the force of gravity, but its viscosity (the parameter that relates the flow of a liquid to the force applied to it) is very high. It may not be a "Newtonian" liquid, for which the flow rate is proportional to the force times a constant viscosity factor.

Answer 7

In terms of physics, the glass could be considered as liquid.but generally,since it is hard and is not mailable,we consider it as solid.you are right ,it takes years to flow. Would you wait until,it completes its operation so that you could pour your drink,you wont,since you yourself consider it as solid though
it ,is yet liquid. This is like putting an answer as a question,along with a question,attached with the answer for it.

Answer 8

You seem to have answered your own question, but I don't agree. I would classify glass as solid. Perhaps it depends on the glass. I have bottles from the late 1700s which seem little changed with centuries - though perhaps microscopic measurements would prove you to be correct.

Answer 9

Sir readalot is right... you seemed to have answered your own question. Thanks for the 2 points though
:o)

Oh...glass is REALLY liquid when you heat it up to 1000 degrees!!! ... it tends to go flat like a pond, then when it cools, it cracks all over like a maze - very cool fun. So I would say that it's a liquid when it's really white hot.... and runny.

Answer 10

I must say you are a lot smarter than what people thought about you.Keep it up.By the way,what name would you give to molten glass?Hope not a Gas.