Well, that’s the way it works. Many are cold, but few are frozen.
Ah, thanks for the excellent cites, Terminus I had no idea this phenomenon could occur in a container of liquid water, and I’ve never seen this personally. All of my Google searches only mentioned water droplets. I have heard of superheating occuring in a microwave oven (which happens for similar reasons, that is, the lack of nucleation sites).
On an early episode of Scientific American Frontiers, MIT prof Woody Flowers, the host at the time, demonstrated it in a test tube.
I had this happen to me once with a water cooler. The cooler was almost empty, and as I watched ice formed in the cup of water I had just poured.
I’d like to try it at home. What conditions are necessary for this to occur?
I’ve witnessed this on a couple occations. Once, pouring water out of a thick walled pitcher from a very cold fridge. The moment that it landed in the cup it turned into slush. I had a roomate place two bottles of beer in the same fridge that shattered before my eyes when I opened the door (he didn’t know I’d turned the temp to freezing a few days before)
I had a professor at Cal Poly, SLO that talked about a bio experiment that he did as a grad student that went a little wrong. He was doing an experiment that involved essentially observing the behavior of fish as very cold temps, putting them in a tank and slowly dropping the temp over time and observing. As it got lower, the fish basically stopped moving until he was beginning to wonder if he’d killed it. The fish abruptly flipped it’s tail, and the movement of the tail caused the water in the tank to turn to ice in a split second. don’t know how large the tank was, but I never had any reason to doubt him on this.
Back to the OP…
Could it be that one bottle happened to have a higher pressure than the others? (or lower, I forget…PV=nRT or something)
Higher pressure. That’s why you can cool down pop and beer to below 0C without them freezing. Once you pop the top they freese instantly. Yes, I have seen this happen.
Maybe the botteles in the middel happened to be bottled on a day that had higher atmospheric pressure. Open one up and see if it freezes.
We do this at the shop to amuse ourselves, sometimes. We use bottled water and leave it in the fridge for at least a couple of hours. Of course you’re going to have to fool around a little bit depending on how cold the freezer section on your fridge is.
Be verrry gentle, though. It takes nothing at all to set off the freezing. I like to see if I can set off the reaction by smacking the bottom with my fingernail, as opposed to creating nucleation sites with foam on the top of the water. Have fun…