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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."
Beam me up, Scotty!
Is this the aluminium glass that Scotty spoke of?
Meh
It's not "Metallic Glass", it's Transparent Aluminum ...
Guns don't kill people; Physics kills people! - John Lithgow as Dick Solomon on Third Rock From The Sun
So am I according to an ex-girlfriend. Thanks, I'll be here all week. Try the veal. Tip your waitstaff.
Well, there's spam egg sausage and spam, that's not got much spam in it.
My first thought is transparent aluminum from Star Trek IV. Only to discover we're closer than I'd think...
This is crap. There have been windows of old buildings "sagging" upwards. The old technology of making windowpanes resulted in glass of uneven thickness, and it makes sense to install it the thick side down. Sometimes the installers did not care enough.
The term glass refers to the structure/lattice. Not to the substance we commonly refer to as glass.
Either way, be prepared to see them as band names any minute now. Or perhaps the band name is "Metallic Glass", thier first album is "Transparent Aluminum"
Glass does not "flow". Perhaps you've read such articles, and they are assuredly all bullshit.
Materials scientists call glass an amorphous solid.
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.
It's widely known and widely taught, but it's not so. Glass does not flow at any measurable rate at room temperature. Glass at room temperature is an amorphous solid, not a liquid.
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.
http://en.wikipedia.org/wiki/Glass#Behavior_of_antique_glass
Except, as noted above, that's not true at all. You learned it in high school because you had a bad science teacher, and shame on "livescience.com" for perpetuating such nonsense. Glass is an amorphous solid, not a 'slow liquid.' It shares one or two characteristics with supercooled liquids, but it is different in several important ways.
First of all, we've known about metallic glasses for years. There's a melt-spinner in the basement of my matsci building that we use to make metallic glasses. Their properties have been fairly well-studied.
Second of all, I don't really like the experiment that these people conducted. They simulated atoms during solidification, but they used microspheres within ANOTHER medium. With glasses, during there is no matrix material within which other molecules are moving. I find their model and extrapolation to be questionable. We are still trying to thermodynamically understand the glass transition and the solid amorphous state compared to the solid crystalline state.
In my very best Canadian/pseudo-Scottish accent, "Hello computer..."
http://www.google.com/patents?id=Kq4yAAAAEBAJ&dq=4256039 Filing date: Jan 2, 1979
Its also been used in large transformers for years. The "technology advance" here worth noting is in being able to produce it while casting/moulding objects that are not thin and flat. It had been done as sheets for years, but casting a part that is something like 7 times the strength of titanium is much more useful. Unfortunately, the problem to solve is its brittleness. Things that shatter are much less useful.
I am a materials engineer at the University of British Columbia in Canada. I recently did a technical presentation on 'Bulk Metallic Alloys' which seems to be the category of materials this 'glass' falls into. BMG's are very exiting materials, their main advantage over traditional alloys is their ability to store energy in elastic deformation. Esentially, they are the worlds best spring material. However; Be careful with your application in using these materials, they may have properties of strong alloys, but they have failure characteristics simmilar to ceramics. Usually they can fail with little to no warning, and catastrophically at that. Crack formation cannot be tolerated. I would not be comfortable with using this material for plane wings. Possibly the landing gear. This material has its niche in underplating for bodyarmor. Send the bullets back. For more information, a good website is http://www.liquidmetal.com/
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.
--
make install -not war
Additionally, I am wondering why the summary compares glass to gel. Gel is a colloidal solution.
Transparent Aluminum isn't fiction and never was.
Al(2)O(3) is sapphire. Personally I wear a watch made of Titanium and Sapphire.
Aside from repeating the old myth that glass can actually sag over hundreds of years, the article says very little. Perhaps a bad summary.
The jist of linked the story is:
A group of scientists in Bristol, Canberra and Tokyo used a material (doesn't say what) analogous to glass, not glass. This material is easier to study. Using this material they claim they were able to understand better what happens on the atomic level as it solidifies, and why it never really becomes a crystal. Nowhere in the article does it explain why this will lead to "metallic glass"
Here is an abstract for the original article. Pretty complex wording, but nothing about metallic glass.
If the answer is war, you are asking the wrong question
... residents of glass houses may now throw stones.
Have gnu, will travel.
"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.
Thank you!! I was going to write something very much like this. Having earned two degrees in science, one a M.S. which largely dealt with material physics, I can say that all materials flow, given enough time. In fact, the term 'rheology' (the study of properties and deformation of materials) comes from the Greek verb rheo, meaning "flow." There's even a Plato quote in there: "All things flow." That being said, the ability of glass to flow is NOT what makes it special. Instead, it is that glass does not posses a crystalline structure, rather, it is an amorphous material. The chemical constituents that make up glass have not combined to form an orderly and repetetive atomic structure of regular, well defined chemical composition. This (at least in part) is what lends glass its special properties. I too had a public school teacher that tried passing on that same misconception, and yes, it is a shameful thing that it continues to get passed along, even by such "reputable" sites as livescience.
From TFA:
An icosahedron has triangular faces. You were thinking of a dodecahedron, perhaps, which has pentagonal faces? The icosahedron's only relation to anything pentagonal (that I'm aware of) is that its dual polyhedron happens to be a dodecahedron.
Glass is not a liquid of any kind, "technically" or otherwise.
Glass is a solid.
Glass is not a crystalline solid.
Glass is an amorphous solid.
Yes, I am a materials engineer.
Slashdot is my Mercer Box.
try 24 years, and he said at the time that it would take decades to figure out the formula.
Oooh baybee.. (ooh baby)
Yer makin' muh cray-zee.. (you're making me crazy)
Every time I look around, it's in my face.
-Billco, Fnarg.com
Glass is Silcon based,
Transparent Aluminum is Aluminum based, it is also known as the gemstone White Sapphire and looks much like diamonds. In fact it has been used for diamond like effects, but doesn't have the brilliance of diamonds (due to different reflective indexes).
Glass MOHS: ~ 5.5
Transparent Aluminun: MOHS = 9. Much harder, better crystaline structure, denser.
And as far as the article's claims, all solids move, but glass definitely is an abnormal material.
Your Jedi mind tricks won't work on us, Physics weenie! Embrace the dark side. And yes, the Physics guys do hate us because applied physics isn't as sexy as blasting muons apart in super-colliders.
What would Richard Feynman do, if he were here right now? He'd do some math and he'd follow through!
May contain traces of nut.
Made from the freshest electrons.
There's no heavy engineering here but one of the things I've always wondered about was the reason cast iron is still used for high quality reloading presses. Steel would be stronger and lighter. And when cast iron breaks, it just snaps. Then someone who thinks deeper than me pointed out that for this application (which requires parts be held in perfect alignment), catastrophic failure is preferable. If a press were to bend, even a little, it would appear to be working fine but produce poor-quality output. A press needs to either be perfectly aligned or obviously broken.
Good presses are heavy. Among the presses I own, a legendary early Hollywood is my favorite (Trust me, the two serious reloaders in the audience are now highly impressed) and weighs over 40 pounds. I wonder if it would be possible to make one of these from a light, strong material that would never bend, only break, under excessive load?
That would be not just cool but very useful for portable applications.