Liquid or Solid?

[swansont]

Glass is actually a liquid of extremely high viscosity. Heavy glass panes standing for a long time have benn noticed to increase thickness at the bottom.

 

Evidence, please.

 

And I second Sayo's rhetorical observation.

[Quixix]

No. It's an amorphous solid.

 

What is the point of having threads if nobody is going to read them before they post?

I have read some arguments in past threads about amorphous solid, supercooled liquids, even some going back to Aristotle!

There is even a quote saying that it is a solid because it will not flow under a "moderate force", without stating neither the amount of the force considered moderate, nor the temperature at which this statement may be true, which makes it completely invalid.

I do not like the use of the term solid (amorphous) in relation to a material that does not have a fixed melting point as true solids do. With increasing temperatures, a glass softens without a given melting point or latent heat of fusion. Crystals may soften, or perhaps lower their yield point, with increasing temperatures, but they reach a definite point at which they undergo a change of phase with considerable absortion of energy.

I suppose we could consider another category of material, neither glass nor solid (in the sense of crystalline), which does not soften with increasing temperatures. Could thermosetting plastics be included in this group?

[Sayonara]

Does anyone happen to know exactly how quickly this alleged creep is supposed to occur?

 

Something like "x millimeters per century" would be handy.

 

I have a cunning plan.