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HalfMooner
Dingaling
Philippines
15831 Posts |
 Posted - 06/01/2006 : 16:59:48
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In this LiveScience article, an ancient Chinese pigment has a new application in understanding quantum mechanics:quote:
Lost Dimension Yields Accidental Discovery
By Bjorn Carey
LiveScience Staff Writer
posted: 01 June 2006
04:24 pm ET
Using strong magnets and a pigment developed by ancient Chinese warriors, scientists turned a three-dimensional system into one with just two dimensions.
The transformation was accidental, but it provides physical evidence for several theories and might help scientists build faster computers.
Our three-dimensional world gives us three options for movement; up-down, front-back, and left-right. Sound waves make use of all three dimensions, expanding like a bubble from their point of origin. Guitar strings, likewise, vibrate in three dimensions when plucked.
Using all three dimensions is not required, however. Ripples on a pond's surface only take advantage of two dimensions. They roll forward and spread side-to-side, but they don't actually propagate up-and-down beyond the pond's surface.
Old is new
"Han purple" is a pigment used more than 2,000 years ago to color Xi'an terra cotta warriors of the Qian Dynasty. Scientists know the pigment as BaCuSi2O6—a highly symmetric crystal structure consisting of layers of spinning atoms.
In high magnetic fields and temperatures between minus 454 and minus 457 degrees Fahrenheit, magnetic waves in Han purple crystals exist in three dimensions. But when the researchers chilled the pigment closer to minus 459.67 degrees Fahrenheit—which scientists consider to be absolute zero—the magnetic waves merged into one large, undulating pulse that was restricted from the up-down dimension by the crystal's copper layers.
"It becomes a reduced dimensional space," study co-author Neil Harrison of Los Alamos National Laboratory told LiveScience. "Imagine a world where you lost the third dimension. Then, of course, everything would be flat. It's kind of like that."
Critical point
The point at which the change of state occurs is called the Quantum Critical Point. Scientists have long used this theory to explain how some two-dimensional based systems, such as high-temperature superconductors, function but had no proof of it until now.
"It's a proof of principle," Harrison said.
. . .
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“Biology is just physics that has begun to smell bad.” —HalfMooner
Here's a link to Moonscape News, and one to its Archive. |
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Cuneiformist
The Imperfectionist
USA
4955 Posts |
Posted - 06/01/2006 : 17:09:11 [Permalink]
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| Great stuff, 'mooner. And thanks for introducing us to the site. It seems to have lots of interesting stuff! |
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Dr. Mabuse
Septic Fiend
Sweden
9688 Posts |
Posted - 06/01/2006 : 18:38:34 [Permalink]
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| Just nit-picking the article... But if ripples on a pond is two-dimentional, then the guitar string is one-dimentinal, not 3D. |
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Cuneiformist
The Imperfectionist
USA
4955 Posts |
Posted - 06/01/2006 : 19:17:24 [Permalink]
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quote:
Originally posted by Dr. Mabuse
Just nit-picking the article... But if ripples on a pond is two-dimentional, then the guitar string is one-dimentinal, not 3D.
I think the point was that when plucked, a string sends vibrations in all directions, or in 3D. And technically, isn't a guitar string in 3 dimensions? I mean, it does have length, width, and height, even if some are very small in relation to others, no? |
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Dave W.
Info Junkie
USA
26022 Posts |
Posted - 06/01/2006 : 19:27:12 [Permalink]
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| Ripples on a pond are 3-dimensional in exactly the same way that a vibrating guitar string is 3D. But, the ripples only propagate in two dimensions, and the guitar string's vibrations only propagate in a single dimension (though the sound waves it creates propagate in three dimensions). The author obviously mistook the sound of a plucked string for the string itself. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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HalfMooner
Dingaling
Philippines
15831 Posts |
Posted - 06/02/2006 : 03:50:45 [Permalink]
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quote:
Originally posted by Cuneiformist
Great stuff, 'mooner. And thanks for introducing us to the site. It seems to have lots of interesting stuff!
Thanks, Cune. I find LiveScience pretty interesting. It's up-to-date, and is written on my layman's level. It also has a fairly regular contibution from Massimo Polidoro of the Skeptical Inquirer.
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“Biology is just physics that has begun to smell bad.” —HalfMooner
Here's a link to Moonscape News, and one to its Archive. |
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