An unusual phenomenon has become the main attraction of the American town.
Scientists have noted that the appearance of such an ice floe is a rare but natural process. It is described in the works of the 19th century, and experts agreed that the disks form a current and small whirlpools. “Since the water in the whirlpool flows more slowly than the main current, it is likely to freeze and turn into a disk,” said a physicist from Harvard University, John Huth.
The unusual floe quickly became a Westbrook attraction: local residents published the “Moon” in social networks, and someone even came to look at it from other cities. Also, the disc was chosen by ducks, which began to ride on the new “attraction”.
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Behold this giant spinning ice disk! ❄️ The image above might suggest someone dropped a small planet in the middle of the Presumpscot River in Westbrook, Maine, but (shocker) that’s not the case. It’s actually a big disk made of ice that’s slowly rotating in place, filled with fascinating physics. ❄️ It would be reasonable to think the river's current is propelling that rotation, but research suggests the object may be spinning on its own. Giant disks like this form not infrequently during the cold winter months, and in 2016 physicists got to the bottom of the phenomenon. The group created a miniature ice disk and floated it in a tank, where they determined that the rotational force was generated by a vortex that formed beneath the disk. Water is at its most dense at 4°C (that’s 39.2°F). As the ice of the disk cools down the fluid surrounding it, that water reaches the four-degree mark and sinks. It flows down and horizontally, creating a swirling vortex. And the larger the temperature gradient—meaning the warmer the river water is compared to the frozen disk—the faster the cooling water will sink. That means the disk spins faster, too. it’ll spin because the cooling water will sink faster. ❄️ That also means spinning disks like this wouldn’t necessarily happen in any body of water. Some lakes may already be at 39.2°F or colder when water starts freezing, which means the cooled water next to the ice wouldn’t sink at all, and thus there wouldn’t be a vortex to rotate the disk. ❄️ The same phenomenon also happens when you place an ice disk on a solid surface, such as a plate of aluminum. If the plate is warmer than the ice, it melts and creates a miniature vortex inside the pooled water beneath. ❄️ Hit the #linkinbio to watch a video of the disk spinning 👉 @popsci 📷 Tina Radel / City of Westbrook
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A 15-minute timelapse of a rotating disk of ice in the Presumpscot River in Westbrook, Maine. Ducks and gulls sit calmly on its surface as drones fly overhead and people gather to watch and take photos. • • [email protected] • • #maine #igersmaine #igersnewengland #ig_maine #ig_newengland #mainetheway #maineisgorgeous #allbeauty_addiction #mainelife #world_shotz #nikonnofilter #winter #ice #icefloe #video #videogram #instavideo #river #floe #mewx #frozen #icedisk #presumpscotriver