July 31, 2008--The Elephant Not In The Room

I was a model builder as a boy. We didn’t have much money to underwrite my hobby so basic materials included cardboard that the laundry inserted in my father’s dress shirts to keep them neat and wrinkle-free; wooden matches; ice cream pop sticks; and, for special purposes, the cellophane that I stealthily purloined from packs of my dad’s Camel cigarettes. The latter, because of its transparency could, in car and boat models, be transformed into windshield glass.

The cellophane was my favorite, not because of the purposes to which I put it but because it seemed to my young and very undeveloped mind a miracle of science and manufacturing—in effect, it appeared to be a form of transparent paper. All other paper was white and brown and decidedly opaque.

If I couldn’t figure all that out I could hardly have been expected to be capable of thinking about the molecular differences between, say, writing paper and cellophane and how somehow that might be related to their different physical properties. That I earned much later. And though I did think to compare the cellophane to glass—though soft and hard both transparent substances, I could get no further than merely noting these superficial similarities (1).

But a few years later when I spent after-school time running errands for the neighborhood glazer, Mr. Perly, I thought more about the nature of glass--another mysterious substance when you think about it. The best I could come up with was to compare it with frozen water in that H2O can be transparent in both its liquid (water) and solid (ice) states.

So you have no idea how pleased I was with myself the other day when in the Science section of the New York Times, their lead story, “Anything But Clear,” concludes that though glass in various forms has been around for thousands of years, scientists still do not have anything resembling a full understanding of what it is.

Not only do they not know, but many who are involved in trying to solve the what-is-glass puzzle are hardly working cooperatively much less with the objective respect for each other that we expect of scientists searching for the Truth. In fact, one glass theorist is so convinced that he has solved the mystery, when confronted with other’s skepticism, says that he ”disagrees violently with them,” with such an emphasis on the “violently” part that others with different views claim that he is in the business of “selling us a used car.” (See article linked below.)

Using the most powerful instruments (electron microscopes) and advanced computer simulations there is at least some agreement that in its molecular structure glass is more like a nearly solidified liquid than a solid. Like a liquid, the arrangement of glass’ molecules, unlike a solid, does not conform to an “organized stacking.” Rather, though as hard as a solid, glass’ liquid-like inner structure is made up of molecules that are jumbled randomly. In a familiar liquid, this random jumbling also includes seemingly-random, perceivable movement. Thus, in a pot or from a tap or in a stream, water is seen to slosh around or flow. When it becomes ice, like other solids, again examined closely with the right instrument, one would see ice’s organized, crystalline molecular stacking.

But not with glass. It appears to have a liquid structure but, unlike water, has a flow rate so pathetically slow that it seems to us to be a solid. Get it?

To give you an indication why Nobel prizes await whomever can make sense of this confusion and these paradoxes, one researcher hot on the trail reveals that things are even more complex and perplexing—there is more than glass to figure out, there are glasses. Plural. According to Peter Harrowell, a professor of chemistry at the University of Sydney, glasses are defined not by a common characteristic they possess but rather by one that they lack—order. As he puts it, “If I showed you a room without an elephant in it, the question, ‘Why is there not an elephant in the room?’ is not a well-posed question.”

That’s glass for you.

But for me, though I do understand why Nobels await whomever solves this one--because of the answer’s implications for other fields: medicine for example (if they could figure glass out they might also be able to structure many critical medications so that they would dissolve quickly and not thus have to be administered by injection); still for that little-boy-model-builder in me, what I await is not the solution to the liquid-solid conundrum but rather why glass and my old cellophane are so magically crystal clear and transparent.

Sorry, I know, I know—they’re not crystals. But glass at least is a liquid. I get it. I really do.

(1) For the curious, cellophane was invented in 1908 by Jacques E. Brandenberger, a Swiss textiles engineer. After witnessing a wine spill on a restaurant tablecloth, Brandenberger initially had the idea to develop a clear coating for cloth to make it waterproof. He experimented, and came up with a way to apply liquid cellulose viscose to cloth, but found the resultant combination of cloth and viscose film too stiff to be of use. However, the clear film easily separated from the backing cloth, and he abandoned his original idea as the possibilities of the new material became apparent. Cellophane's low permeability to air, grease and bacteria made it useful for food packaging—and of course to keep Camel cigarettes fresh.