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?
“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.”
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 ...
Should be ready at quarter past infinity.
Bump for Monday reading.
I loved those “slow glass” sci-fi stories.
Glass fascinates me. Molten glass especially.
I occasionally play with glass in the kiln & furnace. :)
|
|
|||
Gods |
Thanks Jet Jaguar and neverdem. Middle Ages, Corning Museum of Glass, other reasons for the ping.Glass Does Not Flow. Except in Space?To all -- please ping me to other topics which are appropriate for the GGG list. |
||
|
· Mirabilis · Texas AM Anthropology News · Yahoo Anthro & Archaeo · · History or Science & Nature Podcasts · Excerpt, or Link only? · cgk's list of ping lists · |
|||
The Light of Other Days? Classic!
“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.
evolutionists = environmentalists?
Maybe the glass was thicker at the bottom by design, rather than slow flow, or by chance.
http://www.scifi.com/scifiction/classics/classics_archive/shaw/shaw1.html
Gotta love the internet :)
.....they know everything......
See, that’s where you display your gross ignorance. The admission of not knowing is the path to enlightenment. The insistance on certainty derived from blind faith is not a trait of scientists.
Panes of glass in 17th centry New England houses are thicker at the bottom than at the top.
I took some 3’x4’ glass window pains out of a building that we remodeled that were about 60 years old and miked them and every one of them was thicker at the bottom than at the top.
It definatly is liquid silica.
Or maybe the glaziers, while assembling their windows, took their uneven slabs and oriented them thick-end-down, for strength and/or aesthetics.
“Or maybe the glaziers, while assembling their windows, took their uneven slabs and oriented them thick-end-down, for strength and/or aesthetics.”
If that isn’t sarcasm you’re stupid and need to be locked away!
No, the flow rate has been measured
Some people think glass is a slow-moving liquid?
Thanks for that. I’ll bookmark it.
LOL!
bump
“See, that’s where you display your gross ignorance.”
Look! It’s a childishly arrogant poster calling another poster “gross[ly] ignotant”. What are you going to hit me with next... “nanny, nanny boo boo”?
“The insistance on certainty derived from blind faith is not a trait of scientists.”
Tell that to the Global Warming crowd. The Evolutionists are just the same - dogmatically locked onto an idea and willing to punish all who fail to bow the knee.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.