Hi I'm wondering what the explanation for this odd icicle that formed on my ice-tray recently?

 

(2 photo's are attached).

 

Thanks,

 

Grant

Ice expands when it freezes, and does so from the top down, because it's less dense than the liquid water. Which means that during the freezing process, an ice cube will be frozen on the outside but liquid in the middle, and the liquid wants to expand as it freezes. So once in a while, you'll have the conditions where it expands in a narrow spike rather than more isotropically.

 

You might notice that while the liquid water gives you a flat surface, ice will be uneven, and occasionally very bumpy. The ice tray makes it "buckle" somewhat when it tries to expand, but can't because of the ice tray walls. That can give you a weak spot where the spike is forced out. There are probably other conditions that can cause this as well.

OMG!!! You killed a tiny unicorn in your freezer! You monster! :eek:

 

 

 

 

 

<sorry, I figured swansont has already provided a good answer>

Aah, much obliged.

 

I wonder how rare it is?

Could the icicle have fallen into the tray of water at some point in the "ice cycle"? Perhaps having formed previously attached to something else.

 

Then reformed in the way it looks in the photos?

Could the icicle have fallen into the tray of water at some point in the "ice cycle"? Perhaps having formed previously attached to something else.

 

Then reformed in the way it looks in the photos?

 

I doubt it. Swansont's explanation is consistent with the fact that the spike seems to be protruding from the edge of the well, where (just like tectonic plates) the ice-layer on top could squeeze out some liquid water through the crack.

I wonder how rare it is?

This happens with my trays about once a month. I have 4 trays stacked 2x2, and the top 2 trays are prone to this. I always figured it was due to uneven expansion in the freezing process. What I couldn't figure out was why the spikes are always straight. You'd think they would curve downwards as they form due to gravity, but they're always that way, at a less than 90 degree angle but arrow straight.

 

So while we're on the subject of ice cube tray phenomena, can someone tell me why the bottom 2 trays of my 2x2 stack don't pop the ice out as cleanly as the top 2 trays do? I don't always use the same trays in the same order, but invariably, when I go to pop the ice out, the top 2 trays pop out whole cubes while the bottom 2 trays the ice cubes are more fractured and prone to sticking to the plastic.

 

I always figured it had something to do with the bottom 2 trays not having the same amount of air for the freezing process, being blocked by the trays on top of them. Any ideas on this?

ya, but thats a mean spike, that thing is longer than the ice cube itself. i dont see why it would be that long and skinny. though swansonts reason was legit, and makes it possible, i think that would be quite rare due to the length and width of it. could be wrong though.

So while we're on the subject of ice cube tray phenomena, can someone tell me why the bottom 2 trays of my 2x2 stack don't pop the ice out as cleanly as the top 2 trays do? I don't always use the same trays in the same order, but invariably, when I go to pop the ice out, the top 2 trays pop out whole cubes while the bottom 2 trays the ice cubes are more fractured and prone to sticking to the plastic.

 

I would guess that the top trays freeze faster, because they are uncovered, and this may affect how the iced adheres to the tray.

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This happens with my trays about once a month. I have 4 trays stacked 2x2, and the top 2 trays are prone to this. I always figured it was due to uneven expansion in the freezing process. What I couldn't figure out was why the spikes are always straight. You'd think they would curve downwards as they form due to gravity, but they're always that way, at a less than 90 degree angle but arrow straight.

 

The protruding part is already frozen, as is the top of the cube, so they aren't prone to bend. It's not the same as an icicle that forms from water being added to the end.

Certainly if you notice the tip of the spike, the shape seems to be consistent with Swansont's explanation.

 

There was nothing really above it, apart possibly from the above shelving.

Could one freeze some ice rotating slowly in a cylindrical dish or with a neo magnet underneeth stationary water such that the top of bulge of water freezes first and artifically creates this or another intresting effect?