Skip to comments.The Nature of Glass Remains Anything but Clear
Posted on 08/03/2008 6:56:52 PM PDT by neverdem
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?
Theyre 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.
Philip W. Anderson, a Nobel Prize-winning physicist at Princeton, wrote in 1995: The deepest and most interesting unsolved problem in solid state theory is probably the theory of the nature of glass and the glass transition.
He added, This could be the next breakthrough in the coming decade.
Thirteen years later, scientists still disagree, with some vehemence, about the nature of glass.
Peter G. Wolynes, a professor of chemistry at the University of California, San Diego, thinks he essentially solved the glass problem two decades ago based on ideas of what glass would look like if cooled infinitely slowly. I think we have a very good constructive theory of that these days, Dr. Wolynes said. Many people tell me this is very contentious. I disagree violently with them.
Others, like Juan P. Garrahan, professor of physics at the University of Nottingham in England, and David Chandler, professor of chemistry at the University of California, Berkeley,...
(Excerpt) Read more at nytimes.com ...
of interest? Ping.
Click for pic.
But glass? Well, they're not really sure about that one. No consensus yet.
When does one detect a drop in temperature, at the end of infinity?
NYT: “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.”
Hmmm. The NY Times writer (or typist) does not cite it but the article is eerily similar to this:
...which is copyrighted, dated 1996, and starts out: “It is sometimes said that glass in very old churches is thicker at the bottom than at the top because glass is a liquid, and so over several centuries it has flowed towards the bottom. This is not true.”
The New York Times: Outrageous liberal bias, insipid PC drivel, plus the occasional excellent science article.
“But glass? Well, they’re not really sure about that one. No consensus yet.”
They ought to put some evolutionists on it - they know everything.
So you are saying that Baez invented a time machine, traveled to 2008 and plagiarized the New York Times? Whoa nellie!
I thought that glass had more short range order than liquid.
I remember that one; read it in the early ‘70’s.
David Chandler, mentioned in the article, is scary-smart.
Rumor has it that when he was at Penn, a gag greeting card was circulated with a drawing of a smug-looking dragon on the front, with the obligatory puff of smoke.
The caption on the inside read, "Ha! Ha! I'm David Chandler, and you're not."
(Sound of grey_whiskers purring)
Super cooled liquid. Studied it in college in the 70’s. Old lead glass windows are thicker on the bottom because glass flows, just VERY slowly.