I was cleaning some old stuff out of my stereotypically bachelor-neglected refrigerator. Several months ago I put a pitcher of water in the back, but then never used it. Now that the weather is getting warmer, I thought some really cold water would be nice, so pulled it out in order to fill it with fresher stock. I was shocked by what I found inside. This photo is taken looking straight down into the pitcher. You can click it to see it greatly magnified.
Nothing else in the fridge shows signs of freezing, so I hadn't had reason to think the coldness setting was too low, but about 95% of what was left in the pitcher was ice--maybe 6 inches at the bottom. I went to dump it in the sink, but when I did, only a little bit of water came out--the big chunk of ice wouldn't budge. When I looked down on it, I was startled to see many horizontal holes in the otherwise solid ice. You can see them in the photo below. Each one stretches from roughly the center of the ice block to the edge. I have to stress that at no time has this pitcher been in any position in the refrigerator other than bolt upright. That's what makes all of those horizontal bubble/tubes so mysterious to me.
That little dark crescent on the left is a small gap between the ice and the plastic of the pitcher, which had water in it until I poured it off.
Just as surprising, to me, was looking inside the lid:
The ice here isn't a solid block, as in the pitcher, but clearly an aggregation of crystals. This is a little easier for me to explain, at least in broad terms: During cooling/warming cycles in the refrigerator, some water is vaporizing, then refreezing when it rises and hits the lid, forming sort of a hodge-podge of icy mini-stalagtites.
But I remain completely baffled at the horizontal air passages in the solid ice inside the pitcher. Actually, calling them "horizontal" is a bit misleading. You can't tell this from the photo, but looking at the pitcher from the side I can see that they angle up from the edge to the center at about 30 degrees, slightly curvilinear, with the angle steeper toward the center of the block. I've never seen anything like this before. I don't think there's any way I could get this to show up adequately in a photograph, unfortunately. I can only see that much by holding it up to a light.
So I'm putting out a call to the amateur and/or professional physicists among my readers. Can you explain what happened to the water in the pitcher to cause a couple dozen air tracts to form from edge to center, in parallel, curving lines? (Of course, calling them "air tracts" isn't quite accurate, either. They were filled with water, I assume, until I poured the water out and discovered the little buggers.)
Addendum
As the block melted a bit, I was able to slide it out of the pitcher and take a couple more shots of it that should make the orientation of the bubbles clearer. The first pic below is from the side that was at the bottom of the first picture posted above. The second pic below is from the side that was on the left of the first picture posted above, which below you can see is slanted.
And, BTW, the first wiseacre that tells me that I have way too much time on my hands is banned for life from the site!
ice floats in water bc it expands and is less dense. water in the jug would freeze from the top down... makes no sense
ReplyDeleteif parts of the bottom froze before the top, that would explain the upward curvature. the ice at the bottom of the jug would begin to rise.
but that would mean areas of your fridge are colder lower down than higher up. i'd assume the parts closest to the freezer would be the coldest.
give me half a day to think this over (it'll prob come to me at the while i'm at a biggish pot at the table tonight)
J
Those used to be air bubbles on the side of the pitcher. As the ice forms down (along the sides), the bubbles release, and travel at a horizontel like angle clearing a way through the ice that has formed.
ReplyDeleteYou can recreate this quite easily.