Still More Glass Fun Facts: Is Glass Solid or Liquid?

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We have often been told that old European cathedrals glazing show glass is still moving in a semi-solid state as the stained glass panels thicker at the bottom – right? Yes and no – but not for the change in the thickness of the glass.

Way back in 2008, this NY Times Science article delved into the nature of glass -

“…The (cathedral stained glass) 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.”

“…scientists still disagree, with some vehemence, about the nature of glass.”

“Scientists are slowly accumulating more clues. A few years ago, experiments and computer simulations revealed something unexpected: as molten glass cools, the molecules do not slow down uniformly. Some areas jam rigid first while in other regions the molecules continue to skitter around in a liquid-like fashion. More strangely, the fast-moving regions look no different from the slow-moving ones.

Meanwhile, computer simulations have become sophisticated and large enough to provide additional insights, and yet more theories have been proffered to explain glasses.”

“The glass transition does not occur at a single, well-defined temperature; the slower the cooling, the lower the transition temperature. Even the definition of glass is arbitrary — basically a rate of flow so slow that it is too boring and time-consuming to watch. The final structure of the glass also depends on how slowly it has been cooled.”

The (very tech) article includes discussions what would happen withcooling at an infinitely slow rate- so not going to happen in this busy studio.

Click HERE to jump to the 2008 Kenneth Chang article in the NY Times.

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Glass Fun Facts: Gaffer/Composer

More Glass Fun Facts: Bullseye Glass

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Glass Fun Facts – Shattered Glass Predicts Weather

Why is Glass Transparent?

Glass Fun Facts: Why Is Glass Transparent?

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UK Professor Phil Moriarty discusses what makes glass appear transparent in this video by the Sixty Symbols – a collection of videos about physics and astronomy presented by experts from The University of Nottingham.

A photon checks into a hotel. The bell hop asks him ” Can I help you with your luggage?” To which the photon replies, “I don’t have any. I’m traveling light.”

I still have no idea why glass is transparent, but his accent is so good that he doesn’t need to pronounce words right. I guess his explanation didn’t have enough energy and passed right true me. He must assume I know something about being excited.

Previous Glass Fun Facts postings:

Glass Fun Facts: Gaffer/Composer

More Glass Fun Facts: Bullseye Glass

Float Glass Fun Facts

Glass Fun Facts – Shattered Glass Predicts Weather

Historical Glass Fun Facts – How the Invention of Pyrex and The Studio Glass Movement are Connected.

Glass Fun Facts – Shattered Glass Can Help Predict the Weather

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“Tut-tut, it looks like rain.
Yeah, and I’m a little black rain cloud.

Clues to future climate may be found in the way glass shatters.

Results of a study published this past week in the journal Proceedings of the National Academy of Sciences find that microscopic particles of dust can break apart in patterns that are similar to the fragment patterns of broken glass and other brittle objects.

The research, by National Center for Atmospheric Research (NCAR) scientist Jasper Kok, suggests there are several times more dust particles pumped into the atmosphere than previously believed, since shattered dust appears to produce an unexpectedly high number of large fragments.The finding has implications for understanding future climate change because dust plays a significant role in controlling the amount of solar energy in the atmosphere.

Depending on their size and other characteristics, some dust particles reflect solar energy and cool the planet, while others trap energy as heat. “As small as they are, conglomerates of dust particles in soils behave the same way on impact as a glass dropped on a kitchen floor,” Kok says. “Knowing this pattern can help us put together a clearer picture of what our future climate will look like.”

The study may also improve the accuracy of weather forecasting, especially in dust-prone regions. Dust particles affect clouds and precipitation, as well as temperature. “This research provides valuable new information on the nature and distribution of dust aerosols in the atmosphere,” says Sarah Ruth, program director in the National Science Foundation (NSF)’s Division of Atmospheric and Geospace Sciences, which funds NCAR. “The results may lead to improvements in our ability to model and predict both weather and climate.”

Physicists have long known that certain brittle objects, such as glass, rocks, or even atomic nuclei, fracture in predictable patterns. The resulting fragments follow a certain range of sizes, with a predictable distribution of small, medium, and large pieces.

Scientists refer to this type of pattern as scale invariance or self-similarity. Physicists have devised mathematical formulas for the process by which cracks propagate in predictable ways as a brittle object breaks.

Kok theorized that it would be possible to use these formulas to estimate the range of dust particle sizes. By applying the formulas for fracture patterns of brittle objects to soil measurements, Kok determined the size distribution of emitted dust particles.

To his surprise, the formulas described measurements of dust particle sizes almost exactly.

“The idea that all these objects shatter in the same way is a beautiful thing, actually,” Kok says. “It’s nature’s way of creating order in chaos.”

Shattered glass = beautiful thing. Glass artists might disagree.

Click HERE to jump to complete article in the National Science Foundation News.

Other WGS : Glass Fun Facts

Glass Fun Facts: Gaffer/Composer

More Glass Fun Facts: Bullseye Glass

Float Glass Fun Facts

Why is Glass Transparent?

Historical Glass Fun Facts – How the Invention of Pyrex and The Studio Glass Movement are Connected.