Work hit me with a couple late nights in a row, so for a while I thought today’s comic wasn’t going to happen. I decided to split what could be a fairly long comic into more manageable parts. Hope you don’t mind. I’ll post the full thing when the series is done.
Today we begin a journey into the wild world of material sciences, and tackle an age-old mystery in the process. The other week, science news was abuzz over a paper than purportedly slammed the lid shut on the notion that glass flows slowly over the years. The original myth was supported by window glass in really old houses or cathedrals being thicker on the bottom than at the top—as if gravity had slowly been pulling it down. In reality, this is much more likely due to glassmaking techniques at the time.
Before factories were churning out perfectly flat sheets of glass, it had to be made the same way as you would make anything else, by blowing it. Blowers would spin the glass out into a flat disc (or roundel), from which rectangular sheets were cut out. I was a coldworker in a glass studio for 3 years, and during that time, I saw a lot of roundels. For a variety of reasons (both practical and otherwise), they take on a slight UFO shape, being thicker in thThee center than on the edges. With proper technique, you can spin a pretty flat disc, but it will always be slightly thicker in the center. I’ve included an illustration below.
For stability reasons, the sheet would then be installed thicker side down. Case closed, right?
Well… not really. In the next parts we’ll look at what the scientists found when studying a really ancient glass, and how the answer is not as solid as you may think. By that I mean the explanation is pretty amorphous. Know what I’m saying? Newton would be perplexed by the conclusion. Ok, stopping now.
BAM. Strip Search!