Everyday mysteries.
Things out in the world that made me go "huh... that's weird". (Especially things that violate my understanding of how the world works!)
If you post to the #HuhThatsWeird hashtag, I might boost it! ❤️
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No ice spikes so far this year. Not much rain and snow, so I guess not too surprising...
...but also, 4 of the 6 posts I checked have ruptured! I don't have ready access to inspect the others, but I wonder if most of them are like this now.
(Note to self: Outer diameter of posts is about 48 mm, if I want to try replicating this at home.)
The posts in this chain link fence are 4 foot long steel tubes, with walls about 1/8 inch thick. Pretty sturdy.
...except they filled with water, which froze to ice, and that ice has about 10% more volume than the water, and ice apparently don't care overly much about how the steel feels about the matter.
I feel like this might have some bearing on why I've been seeing the weird ice spikes growing out of these posts. Lotta pressure.
So are these kin to the ice spikes seen in ice cube trays? They're so big! And they're not freestanding, but are instead all stuck to the inner face of the posts.
How would they grow? It looks like they were pushed up out of the post and then maybe went through some freeze/thaw cycles that created those stairsteps, and the ridges on that 4th pic in the first post.
I really wish I could set up a camera to capture some growing.
Maybe I could set out a hollow post to grow my own?
Every upcicle is against one wall of a hollow metal post about a meter tall. I see water in there, but maybe 15–20 cm down. (Maybe that's ice too?)
The ice inside the post generally has a lenticular cross section with one arc flat against the metal, although one had a triangular shape.
They protrude up to 8–10 cm, often with one or more stair-steps away from the center, sometimes with an extremely fragile, narrow neck. The upper parts may be round (unlike the part in the post) or flat.
I found these weird "upcicles" growing out of chain link fence posts near Lechmere in #CambridgeMA! I've seen them a few times, and they're *super funky*.
How the heck do these form? Are they in fact a large version of the ice spikes that sometimes form on ice cubes?
See thread for more details.
Unfiltered gallery: https://gallery.brainonfire.net/v2/list?tt=Location=Bike%20path%20along%20western%20Morgan%20Ave,%20Cambridge,%20MA&tt=Content=ice&tt=Content=mystery&mode=raw
I was playing around with a diffraction grating (a child's toy, "rainbow glasses") and decided to look at some LEDs to see if I could tell how smooth or bumpy their spectral output was—I'd heard that cheaper white LEDs tend to have a sharp peak in the blue and a large, wide peak around green/red.
And that's what I saw: A dim region between blue and green. But it's also *narrower* there, which I didn't expect! Maybe there's some diffusion of the light transversely?
3. Diffraction:
...I'm really hand-waving on this one, but I wonder if diffraction across the fingerprint ridges could cause the weird zigzag shadow I sometimes observe.
Maybe I could try replicating with various smooth vs. ridged objects.
2. Overlapping shadows:
When my fingers are almost touching and there's a visible gap, the halo of blurred silhouette around each one overlap with each other. This could cause the appearance of a lenticular shadow between them. I'm not sure why it would cause smaller, shorter lenticular shadows above and below that one, though.
