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Bizarre Properties of Glass Allow Creation of "Metallic Glass"
VindictivePantz writes to mention that scientists have discovered some bizarre properties of glass and are already applying that knowledge to create what is being called "metallic glass." "The breakthrough involved solving the decades-old problem of just what glass is. It has been known that that despite its solid appearance, glass and gels are actually in a 'jammed' state of matter — somewhere between liquid and solid — that moves very slowly. Like cars in a traffic jam, atoms in a glass are in something like suspended animation, unable to reach their destination because the route is blocked by their neighbors. So even though glass is a hard substance, it never quite becomes a proper solid, according to chemists and materials scientists."
One of the interesting aspects of this article is how it highlights the usual thermodynamic balance between entropy and free energy. States of matter in the equilibrium phase attempt to simultaneously maximize entropy, a measure of the statistical likelihood of a given state, and minimize the amount of energy "stored" in the given arrangement of molecules.
The most favorable condition is often a compromise between maximum entropy and minimum energy as highly ordered states, such as tetrahedral or other crystalline arrangements, often act to reduce the amount of stored energy due to minimized interatomic and/or intermolecular interactions and related factors. Pure crystals of substances will often form because the energetic "advantage" of the highly ordered crystalline state is often great enough to overcome entropic barriers.
The model that the researchers propose is interesting because the crystalline state itself introduces a degree of energetic disadvantage due to what is described as "cramming" of the individual crystalline unit cells. I wonder what models they used to form their hypothesis that the glass would eventually form a perfectly crystalline state.
This reporter does not know what they are talking about. The comet failed due to stress risers at the corners of the windows, not because of grain boundaries. Let the materials scientists do the writing. Don't let journalists do science writing. Morons.
Not to mention how the last half is written so poorly that it ventures into incomprehensibility-land.
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Silicon is a metalloid, which has some properties of a metal (or some degree of those properties), and some properties that nonmetals have instead. That's why it can be made into a semiconductor.
That isn't news. This is the big story of 20th Century technology. Exploiting the glass properties of this metalloid is the real news.
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Additionally, I am wondering why the summary compares glass to gel. Gel is a colloidal solution.
Bingo. If glass flowed at any rate the glass vases found in Egyptian tombs would have been puddles. I can't believe this stuff still gets repeated.
"Technology.....the knack of so arranging the world that we don't have to experience it." Max Firsch
There are lenses in very old telescopes that still function perfectly. If glass flowed at room temperature they would become distorted.
You're probably thinking of synthetic sapphire (which is aluminum oxide).
Clearly.
It's not uncommon for amateur telescopes to have mirrors accurate to within 1/10th of a wavelength. If glass flowed, it wouldn't take it very long to go out of figure.
"Royall is part of a group of scientists who think that if you wait long enough, perhaps billions of years, all glass will eventually crystallize into a true solid."
tell me a decent geologist cant locate some billion year old glass from a meteor impact, a volcanic eruption or something.
if you can find a sample you should be able to test this.
Because glaziers were not stupid and put the thick bits that could handle more load at the bottom.
Also pancakes. A soft solid, yes, but solid nonetheless.
Pancakes a solid? They're a foam, surely. Which IIRC puts them in with the colloids.