The Loh Down On Science
Antigravity Birds
The gravity-defying feeding habits of red-necked phalaropes.
What can rednecks teach us about complex physics?
This is Sandra Tsing Loh with the Loh Down on Science
Red-necked phalaropes, or shorebirds, have a unique way of hunting.
They paddle in tight circles to create mini whirlpools that draw in tiny invertebrates, and play "bobbing for plankton."
With a mouthful of water, the birds scissor their beaks, as if CHEWING --which is odd, because they're toothless. So WHY?
To find out, Manu Prakash from MIT built a computer-controlled beak mimicking the birds' movements. He fed the beak a bead of water, then filmed the droplet's fate with a high-speed camera.
As the droplet was compressed, it elongated--like squeezing a balloon.
When the bill opened, the back end of the bead became free first--and instead of dropping down and out, it slid UP, toward the throat.
In this way, prey-packed water droplets move like Inchworms up toward, and then down, the hatch.
The complicated physics has MANY practical applications. Like improving plumbing flow!
And how about one-way straws that don't allow backwash in your Coke? Or at least any tiny plankton, or invertebrates. Ew.














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