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A New Spin On Physical Phenomena

Posted by michael on from the give-it-a-whirl dept.

f00Dave writes "Researchers have discovered "a new physical phenomenon, electrostatic rotation, that, in the absence of friction, leads to spin". I'm a bit skeptical about the implied relationship between physical "spin" (as in rotation) and quantum "spin", however. Still, this is the sort of scientific advance that renews my faith in the system. Go nerds! =]"

3 of 236 comments (clear)

  1. the real article by awaspaas · · Score: 5, Informative

    Here's the journal article from Applied Physics Letters

    1. Re:the real article by zCyl · · Score: 4, Informative

      Or here if you don't like pdf's.

      The article shows much more clearly than the pop news release that the rotation has nothing to do with quantum spin, and is entirely a classical electrostatic phenomenon. I will try to translate the article briefly:

      Essentially, when you apply a charge to the first of the three metal spheres, the charges all repel each other and go to the outside of the first sphere. This exerts a repulsive force against the like charges on the other two spheres, causing an imbalance as more charges are pushed to the far side of the spheres (from the first one) than are on the close side of the spheres. Then, because the second and third spheres have an imbalanced charge distribution, they also exert forces on each other which further displace the charges.

      The displaced charges result in a potential which isn't perfectly balanced like two spheres would be, and the resulting calculation shows an interaction proportional to 1/(r^6), where r is the separation distance, which yields a rotation.

  2. APS article by imkonen · · Score: 4, Informative

    I think this is an example of an overly-zealous press release from a university employee trying to make it sound more exciting than it is. The actual article (+ errata) by the researchers can be found at
    http://ojps.aip.org/getabs/servlet/GetabsServlet?p rog=normal&id=APPLAB000080000015002800000001&idtyp e=cvips&gifs=yes
    Sorry, if you aren't browsing from an institution that subscribes to Applied Physics Letters, you probably won't be able to download the article for free. But I'll be happy to paraphrase what I understood from the article:

    This phenomenon was purely predictable from Coulomb's law and Gauss's laws of electrostatic attraction/repulsion. Many of you should have learned about these in freshman physics. The spheres were arranged in an assymetric pattern, so rotation isn't breaking any kind of symmetry. If you arranged their spherical balls in a mirror image pattern, the rotation will reverse. The authors aren't trying to say they measured some kind of new mystical force that hasn't already been understood for 100's of years but simply that there could be an engineering application that no one had thought of before.

    I'm inclined to agree with the original poster's comment that this has nothing to do with quantum mechanical spin.