Quantum krill, or how to hear a shrimp

Quantum krill, or how to hear a shrimp

The nutrition business is a story of strange bedfellows and odd juxtapositions. Waste streams that once went into the landfill then give rise to high value nutraceuticals, for example. Or politically conservative CEOs who manage supplement companies delivering products to—and making common cause with—lefty-granola consumers.

Another such juxtaposition has come to my attention, and that’s the crossover between quantum physics and the production of omega-3s in the form of krill. (A caveat: To all of the PhDs out there who are about to spit their coffee across the room, allow me a bit of poetic license here.)

Anyone who has looked into a fish finder, as I have, is familiar with the hard, sharp blips returned by gamefish. Their scales, their skeletons, their firm, relatively larger bodies form suitable objects off which to bounce sound waves.

New technology to pursue krill

Not so with the swarms of baitfish those gamefish pursue. I’ve seen those blips, too, and they appear as more of a hazy cloud. The fish are too small, and they’re too close together. Now imagine what a swarm of krill looks like on a sonar screen. Their irregularly shaped, gelatinous bodies and their dense spacing returns an echo that looks more like a smudge.

But researchers are working on ways to interpret the cacophony of echoes that makes up those smudges. To in effect hear what each little shrimp is saying: How fat I am, how fast I’m swimming and what direction I’m going. (The better to catch you, my dear, of course.)

The tool they use is called a stochastic distorted-wave Born approximation, or SDWBA. The approximation is named for Nobel laureate Max Born, a German-born physicist who was driven out by the Nazis and spent much of his academic career in England. Research on how particles scatter, and how they interact with each other as they do so, has provided most of what we know about the nuclei of atoms and thus forms one of the stones in the foundation of quantum physics. Born’s function can be used to approximate the scattering of radiation from indistinct objects, such as a foam cylinder. 

Krill aren’t uniformly cylindrical, of course. But researchers have come up with models consisting of a series of cylinders stacked next to one another wedding-cake fashion to approximate their gently curving and tapering shape. And the expected echo scattering from each little cylinder added together gives a good enough approximation of the actual echo of the wriggling crustacean. Using this, researchers can better interpret the echoes presented by the krill swarming in the Southern Ocean.

So next time you pop a krill pill, give a nod to Max Born and to the researchers who followed in his footsteps. And, lest we get too full of ourselves with the fruits of all this skull-cracking mental effort consider: Whales do all this stuff without even thinking.

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