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"The simplest example of the truly complex"
July 29, 2008 3:57 PM   Subscribe

Anything but clear. 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, yes, but long known to be wrong. Scientists still disagree about the nature of glass, and researchers continue to try to understand its dual personality .

Is Glass Liquid or Solid?

Glass: Liquid or Solid - Science vs. an Urban Legend

Statistical Calculation and Development of Glass Properties

A Brief History of Glass

More Glass History Links
posted by amyms (15 comments total) 7 users marked this as a favorite

 
Very interesting! The story about cathedral glass being thicker at the bottom because of centuries of settling reminds me somehow of that medieval "spontaneous generation" theory. I always liked the image of mice growing out of a combination of old rags and grain -- it made me laugh.
posted by chihiro at 4:32 PM on July 29, 2008


A geology lecturer told me this (that it wasn't a liquid) a few years back, and every single person I've mentioned it to reacted like it was some kind of personal attack. I think there's something about this myth that people really love, and don't like to see broken.

Of course, I think the truth (and the fact that the truth is still debated) is far more fascinating. Thanks for the post!
posted by twirlypen at 4:35 PM on July 29, 2008


It's an amorphous crystalline solid! What is so goddamn difficult about this?
posted by alby at 5:00 PM on July 29, 2008 [1 favorite]


I've never understood why it had to be either one or the other...
posted by pompomtom at 5:07 PM on July 29, 2008


Nice post!
posted by languagehat at 5:17 PM on July 29, 2008


My view of the world has been shattered....
posted by Greg_Ace at 5:57 PM on July 29, 2008 [1 favorite]


Liquid metal
posted by hortense at 7:00 PM on July 29, 2008


Everything you know is wrong (part 1).
Everything you know is wrong (part 2).
I repeat: Everything you know is wrong.
posted by spock at 7:48 PM on July 29, 2008


Great post, amyms! Sad to learn that this old chestnut is a fallacy, but loving the science-y goodness of it all.

I recall reading somewhere an argument for fluidity of glass based on cracks in very old windows healing themselves over centuries (in German homes of great age, if I remember rightly)...sadly, I can't find a link to support this.
posted by retronic at 8:11 PM on July 29, 2008


MetaFilter: Many people tell me this is very contentious. I disagree violently with them.
posted by dhartung at 8:58 PM on July 29, 2008 [1 favorite]


So, was glass made in the 1800 that bad? I've seen a lot of old, uneven, and saggy looking glass windows on old houses and barns. Was that just the oldy-timey version of plexiglass?
posted by The Light Fantastic at 9:17 PM on July 29, 2008


MetaFilter: Many people tell me this is very contentious. I disagree violently with them.

heh. I bought a friend of mine a MeFi membership. She said "So basically I wait until I see something I like or I'm offended by, and then respond?"
posted by dirtynumbangelboy at 9:30 PM on July 29, 2008


I was taught the "flowing glass in old window panes" doctrine in undergrad chemistry as established fact in about 1981. It wasn't until just a few years ago that I discovered it was bogus.

I was obliquely familiar with the discovery of "quasi-crystals" and their five-fold symmetry, but I didn't know it was considered a model for ordinary glass. Interesting.

It's interesting how enormous the numerical values for viscosity can be, I had no idea they had such a range.

It's good to see posts about materials science, thanks.
posted by Tube at 11:32 PM on July 29, 2008


So, was glass made in the 1800 that bad?

Actually it was quite good. As a kid I worked at William Penn's (reconstructed) mansion on the Delaware River. It was rebuilt as a WPA project in the 1930s and painstaking efforts were made to reconstruct the manor and the outhouses using original techniques.

All of the panes of glass were different colors, because that is how they found them in the ground during excavation.

Turns out by 1980 they had figured out that the discoloration (or coloration) wasn't original, it was the result of having lain in the Pennsylvania dirt for two centuries.

One by one every pane was replaced with clear glass made on site in the 18th century methods and despite being a bit wavy and uneven - rolling was done by hand - they looked pretty good.
posted by three blind mice at 11:40 PM on July 29, 2008


I've never understood why it had to be either one or the other...

Gender Phase is a social construct!
posted by backseatpilot at 7:40 AM on July 30, 2008


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