I’ve been finding this interesting structure in my freezer for quite some time. I finally managed to have a camera handy to document it. Yeah, I still use ice trays. Get over it! The photos were taken with the tray in-situ so no melting has occurred.
I filled this tray several hours ago and sat it in the freezer on top of an already-frozen tray. Whether that has any relevance, I don’ t know.
It appears that something is causing water to squirt up or otherwise be projected up above the surface of the cube where it freezes. The shape of the thing makes me think that there was some amount of flow over time – like an icicle upside down. What I can’t figure out is what is the driving force? Why at an angle? Why only one cube?
In other instances the ice prick appears as a needle-thin object. Always at an angle but oriented in random directions. Is this some interesting physics at work or is the ice tray just horny?