 | Bob Crager of Lewis Street Glass is a 26 year veteran in the glass business. Lewis Street Glass is a leading Wichita Glass company, serving the entire Wichita/Sedgwick County area since 1919. They do anything and everything having to do with glass, both residential and commercial. They also do Auto glass. They are located at 743 South Market, facing Kellogg on the South, and you can reach them by phone at (316) 263-8259. You can email Bob Crager at bcrager@lewisstreetglass.com |
Glass
2008-09-01 15:06:00
Is the glass in my windows moving?
Answer: Recently, a number of scientists have made a breakthrough discovery regarding the bizarre properties of glass, stating that glass, yes, the glass we look at everyday and night of our lives, behaves at times like both a solid and a liquid. Amazing stuff! This finding could lead to aircraft being designed and built that look like Wonder Woman’s plane. Such planes could have wings of glass, or something called metallic glass, rather than being totally invisible. I don’t think I’d get on a plane if I couldn’t see the wings pretty clearly.
This breakthrough involved solving the decades-old problem of just exactly what glass is, or is not. It has been known for some time 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. It’s even been stated that even if we lived to a hundred years, the glass in our windows could have moved somewhat during that period of time, but we wouldn’t know it, because we can’t see it. It’s too slow! Just like cars in a gridlocked traffic jam, the atoms in a piece of glass are in something similar to suspended animation, where they’re unable to reach their destination, because the route they’re attempting is blocked by their neighbor atoms. So even though glass has the appearance of a hard substance, it never quite becomes a proper solid, according to the definition used by chemists and materials scientists. The scientific work so far has concentrated on trying to understand the traffic jam, but now a group of these scientists have shown that glass fails to be a solid due to the special atomic structures that form in glass when it cools. Some materials actually crystallize as they cool, arranging their atoms into a highly regular pattern called a lattice, but although glass “wants” to be a crystal, as it cools, the atoms become jammed in a nearly random arrangement, preventing it from forming a regular lattice.
In the 1950s, Sir Charles Frank in the Physics Department at The University of Bristol in the UK, suggested that the arrangement of the “jam” should form what is known as an icosahedron, but at that juncture in time, scientifically he was unable to prove it. An icosahedron is like a 3-D pentagon, and just as you could not tile a floor with pentagons, you cannot fill 3-D space with icosahedrons. That is, you can’t make a lattice out of pentagons. Now, when it comes to glass, there is a competition between crystal formation and pentagons that prevents the construction of a crystal. If you were to cool a liquid down and it makes a lot of pentagons, and the pentagons survived, the crystal cannot form. It turns out that Frank was right, and his team proved this experimentally. You can’t watch what happens to atoms as they cool because they are too small, so the group of scientists used special particles called colloids that mimic atoms, but are large enough to be visible using state-of-the-art microscopy. The team cooled some down and watched what happened. What they found was that the gel these particles formed also “wants” to be a crystal, but it fails to become one due to the formation of icosahedra-like structures. Happening just exactly as Frank had predicted. It is the formation of these structures that underlie jammed materials and explains why a glass is a glass and not a liquid — or a solid. Knowing the structure formed by atoms as a glass cools represents a major breakthrough in the understanding of meta-stable materials and will allow further development of new strong yet light materials called metallic glasses, already used to make some golf clubs. This stuff is generally shiny black in color, not transparent, due to having a lot of free electrons (think of mercury in an old thermometer). Metals normally crystallize when they cool, however stress builds up along the boundaries between crystals, which can lead to metal failure. For example, the world’s first jetliner, the British built De Havilland Comet, fell out of the sky strictly due to metal failure. When metals are made to cool with the same internal structure as a glass and without crystal grain boundaries, they are less likely to fail. Metallic glasses could be suitable for a whole range of products, beyond golf clubs, that need to be flexible such as aircraft wings and engine parts, he said.
You just never know what science will turn up next! There is a group of scientists who think that if you wait long enough, perhaps billions of years, (ok, I’ll wait) all glass will eventually crystallize into a true solid. In other words, glass is now known to be not in an equilibrium state, as when you look at windows in your home or business, although it appears that way to us during our limited lifetimes. That’s slow movement, no matter how you measure it. We’re all happy we don’t have to know all of this scientific stuff to be able to take care of replacing the windows and doors in your home or business, but it’s pretty interesting stuff just the same! Some information was researched on the worldwide web…More next month…
