That glass isn't actually a solid but a very viscous liquid, which is still repeated in many high-school science classes. Often as evidence they point out that you can see the runs and streaks in antique windows, which have become thicker on the bottom than on the top because the glass is sloooowly running down.
This is all false, of course. The old method of making windows was to dip a rod in a tank of glass and raise it up horizontally, creating a ribbon, and the glass ran as it cooled. During installation it was customary to put the thick side on the bottom to make a stronger window.
Put another way, if a hundred or so years can leave glass with runs several millimeters thick, then the Hale Telescope on Mount Palomar would've retained its parabolic shape accurate to 1/10th of a wave for about a day.
Glass is a solid, just not a crystaline solid.
This is all false, of course. The old method of making windows was to dip a rod in a tank of glass and raise it up horizontally, creating a ribbon, and the glass ran as it cooled. During installation it was customary to put the thick side on the bottom to make a stronger window.
Put another way, if a hundred or so years can leave glass with runs several millimeters thick, then the Hale Telescope on Mount Palomar would've retained its parabolic shape accurate to 1/10th of a wave for about a day.
Glass is a solid, just not a crystaline solid.
