That’s right, I’m talking about glass. Apparently glass is both a solid and a liquid, but it doesn’t flow over time. You want to open a scientific can of worms? Produce your own theory on exactly what glass is, why it’s hard, and how it’s still a liquid. Here’s a recent article from the New York Times Online Edition.
The Nature of Glass Remains Anything but Clear
Published: July 29, 2008
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.”
To read more, click on the story’s title. Same goes for the next couple, which are all NYTimes Online articles. The neatest is the one about the glass lab. You can see photos of that by clicking on the following image:
Glass Pretzel made at a demonstration in New York.
But wait…
Glass Does Not Flow. Except in Space?
By Kenneth Chang
[This is a guest posting by Kenneth Chang, a Times science reporter.]
In this week’s Science Times section, I write that glass is not just a slow-moving liquid and that the belief that old windows have sagged over time is bunk, even though scientists still struggle to explain why glass is so solid.
Then there’s Buzz Aldrin’s flashlight.
In 1999, Christie’s East in Manhattan auctioned off an assortment of space memorabilia, including a flashlight that Buzz Aldrin used during a Gemini 12 spacewalk in 1966. The auction catalog mentions:
The flashlight lens became deformed while in the vacuum of space.
And then, there are fun tricks with glass (this is the article for that pretzel) and stained glass window repair:
Designers Teach Glass (and Themselves) New Tricks
Published: May 28, 2008
Summer hadn’t quite arrived in the city over the Memorial Day weekend, but in the garden of the Cooper-Hewitt, National Design Museum, on upper Fifth Avenue, it was several hundred degrees in the shade. Onstage in the Corning Museum GlassLab, four sweat-beaded men in black T-shirts rotated elongated rods — tipped with molten glass hot enough to ignite anything it touched, whether metal, wood or flesh — with the nonchalance of baton twirlers.
A Gigantic Job for Window Fixers
Published: April 15, 2008
After a thousand years artisans are still using muscle, sweat and painstaking craftsmanship to preserve exquisitely painted pieces of colored glass that adorn majestic places of worship.
So, why all this about glass? Because it fascinates me, too. There are colours that could be done in stained glass centuries ago that can’t be recreated. There’s a church in Paris that has a certain blue they can’t reproduce. It was such that the Nazis removed the windows from the church while there was fighting in the city so they weren’t damaged. Pretty cool, huh?
Cheers,
Red Wolf
