The Science Channel told me that Glass is a liquid the other day.
Now obviously, anyone who has ever seen glass knows that for all intents and purposes it is solid. So this can only be a technical minutiae kind of claim.
But the world wide web leads me to believe that the Science Channel has led me astray. At best, the question of whether or not glass is technically a liquid is unsettled science dripping with nuance*. At worst it’s a persistent urban legend.
(*Pun not intended but appreciated.)
Here’s the crux of the matter: With water/ice, the liquid/solid thing is straightforward. When water cools down enough it crystallizes and forms ice.
Glass, on the other hand, doesn’t crystallize. So depending on how you characterize “liquid” and “solid” you may get into a semantic battle about in which state to classify our friend the window pane.
If you’re not interested in the gritty details of science, glass is a solid. If you are, you can check out this highly technical article, or this less technical article and decide for yourself.
This article centers around a guy whose life work has been to study “squishy” materials that defy classification like Peanut Butter, toothpaste, shaving cream, and glass.
On a semi-related note, I had a real life moment that paralleled the Microsoft Bing commercials. In the middle of my Google search results for “Glass is a Liquid” (38,200,000 results) was a link to Amazon for the Philip Glass album Songs from Liquid Days. There were, however, no ads on the results page.
For the record, Bing gave me several Liquid Glass automotive polish links, a few links related to my actual search topic, and 2 ads. One was for “Buy Liquid Glass at eBay you may be eligible for 8% off with PayPal” and the other was for “Glass Liquid” from Target.com.
So, based on this one very limited experience, don’t buy the “decision engine” hype.

Subscribe / RSS
I didn't read your links yet to see if they cover this, but have you heard about the glass windows in old houses? The glass (which I personally consider an EXTREMELY viscous liquid) 'flows,' so the glass is thicker at the bottom then the top.
So here's what I go by. If it has definite volume but not shape, it's liquid, definite shape and volume, it's solid, and neither is a gas. To me glass is a solid. But you know, that's me, the average citizen.
I'd agree that is the normal classification. However, we are talking about a 4th class of semi-solids. What is silly putty? What about that ooglap stuff The Wife® is always talking about? What about shaving cream? Or whipped cream? Or snow?