Monday, March 9, 2009

It's Aliiive!!

Here is something very, very weird that I found on Wired Science:

In the basement of a nondescript building here at Argonne National Laboratory, nickel particles in a beaker are building themselves into magnetic snakes that may one day give clues about how life originally organized itself.

These chains of metal particles look so much like real, living animals, it is hard not to think of them as alive. (See exclusive video below.) But they are actually bits of metal that came together under the influence of a specially tuned magnetic field.

"It behaves like some live object," says physicist Alex Snezhko. "It moves. It crashes onto free-floating particles and absorbs them."

On the spectrum of scientific endeavor, this is very far upstream in the realm where people are just trying to figure how stuff works and why. There is some talk of applications, but at the heart of it, this is really just pure research. Snezhko and fellow physicist Igor Aronson — both tall, thin men who have matching Russian accents and familial rapport — have discovered something really cool, and they're trying to simply figure out what's behind it. Along the way, they could learn something fundamental about how the world works.

Looking at how their particles self-organize, the scientists see echoes of herds of sheep and schools of fish. It seems that there might be some common rules that underpin the behavior and movement of groups of things, but it's not clear what those rules are. It took a couple of years of exhaustive research to figure out how the systems emerge, some of which will be published next week in Physical Review Letters.

Perhaps, by studying this simple system, they can understand what Aronson calls "the fundamentals of self assembly, how nature can organize itself into ordered states." The idea is that if they can determine how magnetic fields and water tension can excite these particles into complex emergent behavior, they will get closer to understanding more complicated, messier systems — like the primordial soup from which life arose on Earth.

"We still don't know what physics is appropriate for biology. This is a wonderful intermediate," Iain Couzin, who heads Princeton's Collective Animal Behaviour Laboratory told in a phone interview. "There's nothing biological about the interactions between the surface swimmers, but their collective dynamics can give us insight into how we can begin to study real biological systems."

Back at Argonne, this is physics for the fun of physics. Though Snezhko tried hard to kill the snakes when they first started forming during an unrelated experiment, they soon became more interesting than the experiment they were ruining. Now he and Aronson can't stop smiling as they talk about discovering something so unexpected. The system exhibits new, dynamic behavior every time they turn it on. It's mesmerizing.

The exciting science stands in stark contrast to the drab appearance of the Argonne campus. The low-slung, plain buildings look more like a middle school — complete with linoleum floors and fluorescent lighting — than a prestigious national lab doing world-class research.

But inside his basement lab, Snezhko shows us a captivating video of what looks almost like a line drawing of a small man — one larger "head" particle trailed by a "body" of skinny chains of particles — swimming around a beaker.

As it starts heading for other chains of particles in an unpredictable and eccentric way, it's nearly impossible not to anthropomorphize the structure. It just acts too much like life. The damn thing practically has ... personality.

"It also has a very bad temper," Aronson jokes, noting that this creature, this figment of nature, appears to "hunt" the other particles. Indeed it does. As you can see in the video, the metallic monster, technically known as a "surface swimmer," acts hungry. As it snatches more particles, it swims faster and faster.

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