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Old 03-04-2014, 10:33 AM   #5
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Default Re: Cool Science Stuff

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Originally Posted by Vis View Post
Pinwheel 'living' crystals and the origin of life

Simply making nanoparticles spin coaxes them to arrange themselves into what University of Michigan researchers call 'living rotating crystals' that could serve as a nanopump. They may also, incidentally, shed light on the origin of life itself.

The researchers refer to the crystals as 'living' because they, in a sense, take on a life of their own from very simple rules.

Sharon Glotzer, the Stuart W. Churchill Collegiate Professor of Chemical Engineering, and her team found that when they spun individual nanoparticles in a simulation—some clockwise and some counterclockwise—the particles self-assembled into an intricate architecture.

The team discovered the behavior while investigating methods to make particles self-assemble—one of the major challenges in nanotechnology—without complicated procedures. When the pieces are a thousand times smaller than a grain of sand, normal techniques for building structures are no longer effective.

For this reason, researchers like Glotzer are exploring ways to make order develop naturally from disorder, much like what may have occurred at the very beginnings of life.

"If we can understand that, not only can we begin to imagine new ways to make materials and devices, but also we may begin to understand how the first living structures emerged from a soup of chemicals," said Glotzer, who is also a professor of materials science and engineering, macromolecular science and engineering, physics, and applied physics.

"One way biology approaches the challenge of assembly is by constantly feeding building blocks with energy. So, that's what we did with nanoparticles."

Recently, researchers in the field have found that if particles are given energy for some basic motion, such as moving in one direction, they can begin to influence one another, forming groups. Glotzer's team looked at what would happen if the particles all were made to rotate.

"They organize themselves," said Daphne Klotsa, a research fellow in Glotzer's lab. "They developed collective dynamics that we couldn't have foreseen."

The team's computer simulation can be imagined as two sets of pinwheels on an air hockey table. The air pushing up from the table drives some of the pinwheels clockwise, and others counterclockwise. When the pinwheels are tightly packed enough that their blades catch on one another, the team found that they begin to divide themselves into clockwise and counter-clockwise spinners—a self-organizing behavior known among researchers as phase separation.

"The important finding here is that we get phase separation without real attraction," Klotsa said.

She calls the self-sorting counterintuitive because no direct forces push the same—spin pinwheels together or push opposite-spinners apart.

The separation occurs because of the way the pinwheel blades collide. While a pair of pinwheels may be spinning in the same direction, where their blades might meet, they're actually moving in opposite directions. This means that the blades will push into one another and stick together, causing the pair of pinwheels to rotate as one, at least briefly.

In contrast, the blades of opposite spinners are moving in the same direction where they meet, so they don't stick together. Since same-spinning pinwheels spend more time linked up, they gradually accumulate into groups.

When the pinwheels divide into clockwise and counterclockwise tribes, the boundary between the groups becomes a thoroughfare for particles in the mix that aren't spinning. The blades at the boundary push these nonspinning particles along the border, making them less likely to dive back into the denser collections of pinwheels. The team said this phenomenon could potentially be harnessed as a sort of nanopump to transport objects in a device.

While the computer simulations were in two dimensions, as though on a flat surface, the team anticipates that rotating particles could also grow into 'living,' three-dimensional crystals. The particles would be free to turn their spin axes in any direction, so they could eventually form a 3D liquid crystal with aligned axes.

The results appeared online in this week's issue of Physical Review Letters and will be presented at a March 6 meeting of the American Physical Society. This work was funded by the U.S. Department of Energy.

http://phys.org/news/2014-02-pinwhee...tals-life.html
Interesting article.

It may attempt to explain some things about evolution and appears to lean on the "Quantum Entanglement" theory as its basis, but it (as well as many other evolutionary theories) still has a ways to go to explain specific and relevant evolutionary processes.

One of the things that has always been missing from scientific explanations about evolution is the connection between "need" and development.

For example, in many dissertations on evolutionary development of monkeys, it is said that they began as small mammals who took to the trees for safety from larger predators. These animals ate the leaves, soft stems and insects in those trees.

But living in trees required use of all of their arms and legs to keep them from falling and they are said to have thus developed tails to allow them to securely anchor their bodies leaving their hands free to gather food.

But the thing that never seems to get explained is HOW this came to be.
Developing a tail was surely an advantage but what caused the tail to emerge?
Even if a prehistoric mammal could have thought that such an appendage would be useful, I doubt it simply willed it into existence. So much of evolutionary science explains "after-the-fact" conditions such as "having a tail allowed them to exist in the trees...., etc., but very few touch on what occurred prior to such development and what specifically triggered that development.

Then there's the issue of time.
Surely a tail did not develop overnight and probably took hundreds of thousands or possibly millions of years to develop, so what did these animals do in the meantime?

Perhaps theories such as the one you posted will begin to shed some light on such development and I suspect that if this theory proves useful, the notion of "willing" something into existence may not be so far-fetched.
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