Anarchemitis said:A little known fact is that the above "fact" is actually so much bollocks" the myth arose when people examined church stained glass and found the bottom was thicker. This lead them to conclude it was "flowing" very slowly under the influence of gravity. But actually the reason is simply that glass making back in medieval times didn't produce flat panes like now; so engineers constructing the windows would put the think end of the cut-to-size glass piece at the bottom to lower the risk of it being top heavy and just falling out.Rabid Toilet said:Glass has properties of both solids and liquids, and is thus essentially undefined.