Science lesson: Shattering Pyrex

Yesterday as I was putting away some dishes, two Pyrex measuring cups that I had nested together on a shelf above my head came crashing down and bounced off of my water glass on the counter onto the floor. I put the measuring cups back up on the shelf, stuck the baby in her highchair, and set about cleaning up the shattered water glass. Later in the day, when my friend Adam and I were getting ready to make margaritas, I pulled down the measuring cups and found that they were wedged together. It sometimes happens, since they aren't really meant to be like that, but unlike all previous times, just giving them a little twist didn't do the trick. I assumed the impact from the earlier fall is what made the difference.

Adam and I considered the possiblities as we took turns twisting and prying at the cups. Hot water? Cold water? Which would make the glass expand and which would make it contract? And besides, if they both expanded or contracted, what good would it do? Where was an engineer when the humanities and sociology majors needed one? (Oh, right. He was at work, celebrating his 30th birthday with a singing telegram in the form of a gorilla in a tutu.) We decided that ice would make the glass contract, both of us having some memory of water being an anomaly because it expands as it freezes. But then Adam started to worry about whether the glass would break if exposed to extreme temperatures.

"No, I think Pyrex is meant to survive temperatures like that. That's why you bake with it," I said. "Besides I think it was made for like train lanterns or something initially. I read an article about it once. Maybe in the New Yorker. I mean, doesn't that sound like a New Yorker kind of article? A twenty-page exposition on the history of Pyrex?"

Adam turned to Google, typing in "nested pyrex stuck," or something along those lines. And then began reading articles about an investigation into exploding Pyrex. After a few of those he came to a message board where people had discussed exactly our problem. Drinking glasses would be easier to separate, as Pyrex by design doesn't expand or contract quite as easily with temperature changes, but it could be done. I filled the one-cup measure with ice and poured water of the top of it and then submerged the quart-sized measuring up into a sink of hot water.

Adam went back to browsing articles about Pyrex that had essentially exploded at high heat. I tried wiggling the measuring cups apart after a minute, but stepped away when I discovered they were still wedged together quite firmly. Adam read a paragraph to me, and I stopped him.

"Pyrex isn't supposed to do that. And those were probably at much higher temperatures that just the water from my tap." And then there was the sound of shattering glass, as the outer measuring cup broke. Big pieces came off the top, shards of glass scattered around the sink and onto the floor, and the bottom part sat in the sink full of little cracks.

Incidentally, this is the second time I've managed to do in some Pyrex. At one point I managed to drop a large baking pan on the floor at just the right angle to break it into several large pieces.