Chalk this up under "Blogs You Ought to be Following". The Tumblr Fuck Yeah Fluid Dynamics is a great place to find succinct, clear explanations of the forces that make things flow. In particular, they're fantastic at posting explanations behind things you see in YouTube videos, both viral and obscure.
The video above — in which a nice Siberian guy tosses boiling water off his balcony and creates a cloud of snow — has been making the rounds recently. Here's how Fuck Yeah Fluid Dynamics explains it:
Several effects are going on here. The first thing to understand is how heat is transferred between objects or fluids of differing temperatures. The rate at which heat is transferred depends on the temperature difference between the air and the water; the larger that temperature difference is the faster heat is transferred. However, as that temperature difference decreases, so does the rate of heat transfer. So even though hot water will initially lose heat very quickly to its surroundings, water that is initially cold will still reach equilibrium with the cold air faster. Therefore, all things being equal, hot water does not freeze faster than cold water, as one might suspect from the video.
The key to the hot water’s fast-freeze here is not just the large temperature difference, though. It’s the fact that the water is being tossed ...
This popular video is a great example of why cartoon-level humanization of animals doesn't really work. Yes, it looks like this clam just stuck its tongue out and licked up a bunch of salt. But clams don't have tongues. Let alone giant tongues that would take up most of the clam's body.
In reality, that's a foot.
Have you ever looked at a mollusk like a clam and wondered whether and how it moves? That foot would be how. Clams use it for digging, because they live most of their lives buried in sand and mud. It can also be used for limited movement—usually, to get back into the water and then get reburied in the sand and mud.
Business Insider interviewed a couple of marine biologists who agree that the whole "salt-licking" thing is really just a side effect of this clam sticking out it's gooey foot.
Brian Bayne, a marine researcher from the University of Sydney agreed that this clam is definitely not feeding.
"These clams live buried in mud and they get there by digging-in with a large, mobile foot (which looks convincingly like a tongue), he said. "This clam, stranded on someone's floor, is trying to dig itself back home."
To take away the sting of scientific accuracy, after the cut you will find another YouTube video in which a (happy?) clam successfully uses its foot to return to the ocean. It's pretty cool.