After I place a filled ice tray into the freezer, and it has begun to freeze, ice stalagmites begin to appear on some of the cubes. There is only one stalagmite per cube (if that) and they are all on about a 15 degree slant, although not necessarily in the same direction as the other stalagmites in the same tray.
These things are about 3/4 to 1 inch tall. What the heck is happening in there to cause these things to form? I have noticed that they are formed before the cubes are fully frozen. In case it is of any relevance, the tray is plastic.
My vote is that the ice cubes are freezing inwards from the outside of the tray. Since water expands as it transitions into a solid (aka: ice), the stuff has to go somwhere, namely out the unfrozen area in the middle at the top.
While the refrigerator may not be level, (I doubt it is)and the freezing process may cause the water to expand (I don’t doubt it does), but none of that – to me, anyway – explains why these ONE INCH LONG spikes are forming out of the tops of the cubes. Do they do this in anyone else’s 'fridge? I have been making ice cubes for roughly 30 years, and this is my first encounter with this phenomenon. I’m sure I’ve had tilted refrigerators in those years, and that water’s properties haven’t changed all that much, either. No, something else is happening here. Any other ideas, anyone?
No, they aren’t stacked, but I did notice an error in my original question. I should’ve said that the spikes are on about a 75 degree angle, not a 15 degree one. (That’s what happens when you’ve been using altered keypads on someone else’s PC!)
I think cornflakes is correct, but a bit misleading because it sounds like the water simply oozes out in the middle. When the water is partially frozen, what you have is liquid water completely sealed inside ice and being squashed hard by the expanding ice. Because of the pressure, the water remains liquid even at slightly below freezing - i.e. supercooled. Eventually the pressure becomes so high that the water breaks through the ice where the ice is thinnest - i.e. the middle of the top surface. The supercooled water squirts out and, suddenly relieved of the pressure, freezes midair before it splashes down.
Oh-h-h-h, I see. My apologies to cornflakes! I guess it’s possible that they are doing this, even though it seems incredible that the squirted-up water would freeze so quickly in air that is only about zero degrees Fahrenheit. Sure wish I could see that happen!
smartin, you may be from Milwaukee, but please, don’t say things like “only about zero degrees Fahrenheit.” Texans can’t comprehend statements like that. In any case, no apology is necessary but thanks all the same.
My plastic trays used to make ‘peaked’ cubes too, but the peaks weren’t quite as pronounced as yours (unfortunately for science/trivia, I did a few repairs to the fridge a while back which probably changed the freezer temperature.) It may be that what scr4 described is happening in your freezer, but in mine, the unfrozen water oozed out a hole or crack in the middle, freezing as soon as it came out. What finally froze in the middle put the final peak on the cube.
scr4, I would think that if this was an abiabatic process (the pressure keeps the water inside the cube from freezing), then the cube would freeze completely once the stalagmite it formed and the pressure is relieved. On the other hand, if you’re right, then the cubes should skim over, and a while later the peak should suddenly push out instead of slowly forming. That said, does anyone have a camcorder with IR imaging that we can put into smartin’s freezer to test this theory?
The usual way for stalagmites to form is via water dripping on that spot. If that’s the case, there might be some evidence directly above the stalagmite, such as a wet spot on the freezer ceiling or a mini-stalactite. Have you ruled out this possibility, smartin?
If it were water dripping, it would be a vertical stalagmite, these are at an angle. Also, stalagmites from dripping are usually cones, and these are more of a rod.
In a previous house, I had the same thing happen several times. And longer than just an inch, sometimes two or three inches. It always seemed to be the same angle which I figured was related to the crystal structure of ice. But other than that, I haven’t any idea why it did it.
I don’t recall the explanation for these “ice stalagmites”, but it’s not due to water dripping from above. The same thing can occur in nature, on ponds and other bodies of water where there’s nothing above the surface. I think that the reply above that blamed this on ice expansion is correct, although why it assumes that tilted form I don’t recall. This is another of those weord physics phenomena that is treated in Jearl D. Walker’s “Flying Circus of Physics”, and that book lists references on the subject. I don’t have it here, so I can’t give you the citations, but I’ll check it out later today.
I get these in my ice cube tray, and it DOES look weird!
I have Jearl Walker’s book, and as near as I can tell, he doesn’t treat this question specifically, although 3.104 may come close: Ice columns growing in ground. It’s “answer” refers to 3.106, Winter buckling of roads.
While I like the “supercooled water squirting out, then freezing” theory better, I have another candidate explanation.
The ice cubes as they are freezing are kept at 32 degrees F, warmer than the rest of the freezer. Air currents are caused by the higher temperature of the ice, which draws air across horizontally across the ice surface toward a point in the middle, causing a small amount of sublimation from the surface. At the middle of the cube, the air currents come together, and deposit the water molecules there. The tilting is caused by pre-existing air currents flowing in the direction of the tilt.
You should be able to peak into the freezer, and with several observations, tell if the peaks grow gradually (consistant with this theory), or appear suddenly, fully formed (consistant with the squirting theory).
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I have to say that to me, this sounds like nonsense. Firstly, when I’ve seen (admittedly much smaller) versions of this, the little projection is always conical. Why would this be the case if the water had spurted out? Why not so with greater mass of ice nearer the end of the stalagmite? Why not some where the water had squirted out at an angle other than perpendicular to the surface of the ice-cube? Secondly, water, even supercooled water, takes some time for the crystallisation process to spread through the mass of water. Why would this always be more rapid than the action of gravity on the mini-fountain?
Additionally, I don’t recall ever having seen these type of formations on frozen lakes or canals, or even on the surface of water frozen in buckets or the like. Why not?
Unfortuanately, I still don’t have an answer. My WAG, it’s the deposition of water from the heavily saturated atmosphere at one site due to some form of nucleation.
RM Mentock: Are you referring to standing waves? These can become complicated when irregular vessels are involved.
Wow, what a group! I am really impressed with this bunch. I’ve asked people about this before and all I got were blank looks and muffled grunts. I appreciate your interest, because I was beginning to think that I was a lone lunatic. Now I know that I may be crazy but THERE ARE MORE OUT THERE LIKE ME!
I was delighted to see that website you found, because it spares me the trouble of posting images(which was a great idea, and I regret that I didn’t do it at the onset). The ice peaks in those pictures are exactly like the ones I get, with the exception of the two which are more wedge-shaped. Mine are all spike-shaped.
[By the way, I’m NOT from Wisconsin; I’m FROM Tennessee, but I lived in Houston for 7 hot, humid, miserable years, during which I complained constantly about the heat. That complaining landed me up here, and I must admit that I love this weather. At least the humidity is generally <96%.]
I may try that idea about altering the air flow, if I can figure out how to do it. This is a cheap refrigerator (apartment style), and I’ve had 2 apartments in the same complex, both of which made these odd ice cubes. It IS a frost-free model, and it DOES make noises, and it even “shudders” sometimes.
I DO use them as handles! They’re quite handy, actually. You just loosen them with a slight twist to the tray (keeping it right-side-up), then lift out only the ones you need, replacing the tray so that the next person – who may not be so industrious – has to dump the rest out and refill the tray.
Does anyone know if Mr. Wizard ever visits this site?
