Captured in portrait mode by Dan Brown while hiking with his father near the head of Loch Fyne (home of the finest Loch Monster) in the Scottish Highlands, this is a video of a naturally occurring spinning ice disc. Per Wikipedia while I make a bowl of cereal with hot chocolate:
Ice discs form on the outer bends in a river where the accelerating water creates a force called ‘rotational shear’, which breaks off a chunk of ice and twists it around. As the disc rotates, it grinds against surrounding ice — smoothing into a circle.
The ice circle lowers the temperature of the water around it, which causes the water to become denser than the slightly warmer water around it. The dense water then sinks and creates its own circular motion, causing the ice circle to rotate
Mother Nature, she’s a trip, isn’t she? Just when I think I’ve seen it all, she throws a naturally formed spinning ice disc at me. And hard too, like Captain America throws his shield. *doubled over in the snow* My nuts.