21–30 of 76 posts
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The near-perfection of the circular shape is what really makes it stand out. It's strange to see such regularity in natural phenomenons.
maybe it's a ~logical result of taking the limit of a fractal ?
I wonder if, in the absence of gravity (and thus no issue of buoyancy), a spherical ice ball would form in a stream of slow moving cold water...
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I am certain that someone would have noticed this happening before. Maybe it is a symptom of climate change. Instead of ice being dammed up earlier in the river, it moves further down and freezes in the currents.
This sort of speculation harms the argument for climate change more than it helps it. To convince others, it's better to build a case on scientific fact and large-scale issues than one specific interest of a likely-natural oddity.
This particular hypothesis seems to be invalidated by the fact that the phenomenon was observed before, back in 1895. See the wikipedia link in comment above.
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Not that large
I don’t know the earth is pretty big :) It is a near perfect circle, as are all the other planets & moons we observe. Maybe the rings of Saturn? Just kidding around really, but I have to imagine that pockets of circular water currents like this, are more common than we would think. We just can’t easily observe the dynamics of water flow until something like this happens, where a bunch of ice builds up and makes it ob…
Vortices in a near-2d-flow like a river will absolutely be circular, vortices need to be coherent in some plane in order to sustain themselves.
The specific circumstances here must be that that the water is on the edge of freezing during downstream flow and there is a naturally-very-long-lived vortex in one region for it to initially form the ice-disc. Must also be followed by some very-gently-bounceing-off-the-edges, and the river never getting too thin for it to get stuck.
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The earth is pretty lumpy, what with mountains and oceans, and the earth is where I learned the term "oblate spheroid".
Less lumpy than a billiard ball. The mountains and trenches only seem significant because the whole thing is so big. Totally not a perfect sphere though, yeah.
Well, no: https://ourplnt.com/earth-smooth-billiard-ball/
The myth is springs from the fact that if you had a smooth earth with a radius of center to Mariana Trench, and another smooth earth with a radius of center to Mt. Everest, you could shrink both of them by the same factor and fall within allowed billiard ball specifications. That says nothing about smoothness, only about the allowed size of ball.
If you actually shrunk the earth we're living on, the ball would still be rejected as quite too rough.
I wonder if, in the absence of gravity (and thus no issue of buoyancy), a spherical ice ball would form in a stream of slow moving cold water...
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What would drive a stream in the absence of gravity?
I assume that can be artificial. Just use a pump.