Question: Is the glasses classify to fluid? somebody said that if we leave it in a place for a period of time, the upper end will be thinner and the bottom will be thicker. what is the definition of fluid. is it from the property or from the microcosmic molecular structure(arrangement)?

Lilian Hunt answered on 18 Mar 2014:

I’m afraid this is urban legend, I think from the idea that old window panes seem to be thicker at the bottom. But glass is in fact a solid. It is technically an amorphous solid as it doesn’t have a long range crystal structure if you talk about how its molecules are arranged. So structurally some people might say that glass’s molecules are arranged kind of like a liquid rather than your usual crystalline solid but ultimately it is just a different type of solid which won’t flow like a liquid.

If you’re interested in this sort of thing have a look at the world’s longest running experiment here: http://smp.uq.edu.au/content/pitch-drop-experiment