I was thinking about the pictures of the Kibble Palace Conservatory that I posted on the blog last time and its amazing sense of “plasticity” when Mehmet sent me a link to a very interesting and relevant NYT article titled: The Nature of Glass Remains Anything but Clear By KENNETH CHANG.
Chang starts out with this unusual factoid: “Peer into its molecules, and glass is indiscernible from a liquid.” He then goes on to ask: “So how can it be hard? And how does it get that way?”
Evidently, scientists are still puzzling about this—although there seems to be as much contention about whether the problem has actually been solved as to what the solution is.
The often quoted “fact” that “panes of stained glass in old European churches are thicker at the bottom because glass is actually a slow-moving liquid that flows downward over centuries” is incorrect according to the author. He states “medieval stained glass makers were simply unable to make perfectly flat panes, and the windows were just as unevenly thick when new.”
“The tale contains a grain of truth about glass resembling a liquid, however. The arrangement of atoms and molecules in glass is indistinguishable from that of a liquid.”
“For scientists, glass is not just the glass of windows and jars, made of silica, sodium carbonate and calcium oxide. Rather, a glass is any solid in which the molecules are jumbled randomly. Many plastics like polycarbonate are glasses, as are many ceramics.”
The article proves to be an interesting peek into the ongoing scientific research of this “obscure” but important area of natural phenomenon. Take a look, it’s quite fascinating.
Alan