Understanding the Nature of Glass

This is from over a month ago, but there was a wonderful article for all the closet material scientists out there in the New York Times on Glass a few weeks ago.

Here is an except:

It is well known that panes of stained glass in old European churches are thicker at the bottom because glass is a slow-moving liquid that flows downward over centuries.

Well known, but wrong. 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. But how can a liquid be as strikingly hard as glass?

“They’re the thickest and gooiest of liquids and the most disordered and structureless of rigid solids,” said Peter Harrowell, a professor of chemistry at the University of Sydney in Australia, speaking of glasses, which can be formed from different raw materials. “They sit right at this really profound sort of puzzle.”

It’s a great article, and a wonderful exploration of an area of material science that most people assume they know more about than they do.

New York Times: The Nature of Glass Remains Anything But Clear

Enjoy.