Slashdot Mirror


Amherst Researchers Create Magnetic Monopoles

An anonymous reader writes "Nearly 85 years after pioneering theoretical physicist Paul Dirac predicted the possibility of their existence, an international collaboration led by Amherst College Physics Professor David S. Hall '91 and Aalto University (Finland) Academy Research Fellow Mikko Möttönen has created, identified and photographed synthetic magnetic monopoles in Hall's laboratory on the Amherst campus. The groundbreaking accomplishment paves the way for the detection of the particles in nature, which would be a revolutionary development comparable to the discovery of the electron." That's quite a step beyond detecting monopoles; the Nature abstract is online, but the full paper is paywalled.

15 of 156 comments (clear)

  1. Plus, they're worth 25 RU by nightfire-unique · · Score: 5, Funny

    .. and can certainly help in the fight against the Ur-Quan!

    --
    A government is a body of people notably ungoverned - AC
  2. Monopole Magnets by Anonymous Coward · · Score: 5, Funny

    "The secrets of magnetism"

    Requires Superstring Theory, Silksteel Alloys

    Leads to Nanominiaturization, Unified Field Theory
    Enables: Terraform Mag Tube

    1. Re:Monopole Magnets by Mordok-DestroyerOfWo · · Score: 4, Funny

      And yet our tanks can still be beaten by archers.

      --
      "Never let your sense of morals prevent you from doing what is right" - Salvor Hardin
  3. Are we sure. . . by smooth+wombat · · Score: 4, Funny

    someone wasn't playing a trick on them and was turning the electric can opener on and off in the other room?

    --
    We will bankrupt ourselves in the vain search for absolute security. -- Dwight D. Eisenhower
  4. Re:Verry cool IF TRUE by tomhath · · Score: 5, Funny
    FTFA:

    Hall's team adopted an innovative approach to investigating Dirac's theory, creating and identifying synthetic magnetic monopoles in an artificial magnetic field generated by a Bose-Einstein condensate, an extremely cold atomic gas tens of billionths of a degree warmer than absolute zero.

    "Verry cool" is an understatement.

  5. This is cool, but by Anonymous Coward · · Score: 5, Insightful

    they haven't really found a magnetic monopole. They've created a long skinny solenoid with ends that are far enough apart that they look like independent monopoles.

    Great physics, terrible summary.

  6. Re:Contradicts current theory? by tibit · · Score: 4, Insightful

    That's some misunderstanding of what a scientific theory is, right there. A theory must have predictive power - it must be useful for something, that is. Electromagnetic theory, so far, is extremely successful precisely because it works where we need it to work. The monopole demonstration doesn't change it one iota - neither your computer nor your electric plant have stopped working overnight.

    It doesn't matter in practice that it doesn't work everywhere, and there's no need to rewrite anything and there's no contradiction. We know that the classical theory of electromagnetism, well, applies to classical scale phenomena, under certain conditions. No scientist in their sane mind would insist that this effect contradicts the classical theory. It's simply outside of the classical theory's scope, just as relativistic effects are outside of the realm of classical mechanics.

    The real problem is with extremely widespread, naive understanding of what a scientific theory is and that there are limits to applicability of any scientific theory of nature. The phrase "law of nature" is perhaps the biggest romanticism-imbued snafu there ever was in popularization of science.

    --
    A successful API design takes a mixture of software design and pedagogy.
  7. Pseudoparticles by Sockatume · · Score: 5, Interesting

    These are pseudoparticles. They're like magnetic monopoles in almost all ways, but they arise from the collective motion of other particles rather than actually existing in and of themselves (think about having an electron hole, versus having an actual positron). The breakthrough is that they've made the first pseudoparticle in a quantum mechanical regime that allows it to behave consistently with the real particle.

    --
    No kidding!!! What do you say at this point?
    1. Re:Pseudoparticles by jeffb+(2.718) · · Score: 4, Insightful

      I like the "electron hole" analogy. Electron holes aren't as spectacular as positrons; they don't annihilate electrons and generate gamma-ray photons. They can, however, "annihilate" an electron in a semiconductor to produce a visible photon -- and that's how we get LEDs.

      This "monopole" won't let us build super-motors or disintegrate protons at will. But I wonder if, recreated in a more robust medium, it could have its own interesting uses?

  8. Re:Contradicts current theory? by Kongming · · Score: 4, Funny

    Also, would this allow for the development of an over unity, energy from nothing generation machine.

    The answer to that question is always, always no. Except when it's still no, in which case it is no. No.

    In conclusion, no.

    --
    (no sig)
  9. "but the full paper is paywalled" by Anonymous Coward · · Score: 5, Insightful
    Unless you are really up on your Maxwell's equations and condensed matter physics, you wouldn't get much out of the actual paper. When I hear all the bitching and moaning about paywalled papers and how "the people" need to see the paper, I can't help but think that 99.999% of "the people" couldn't get past the intro paragraph because of all the field-specific details. That's why there are places like Scientific American and numerous science-writer blogs to translate this for the layman. If you can understand the following, then you most likely have access to the actual article, and if you don't know what this all means, then you are far better off going for the layman's summary:

    The spinor order parameter corresponding to the Dirac monopole14,17 is generated by an adiabatic spin rotation in response to a time-varying magnetic field, B(r, t). Similar spin rotations have been used to create multiply quantized vortices18 and skyrmion spin textures19. The order parameter Y(r, t)5y(r, t)f(r, t) is the product of a scalar order parameter, y, and a spinor, f~ðfz1,f0,f{1T¼^ jfi, where fm5Æmjfæ represents the mth spinor component along z. The condensate is initially spin-polarized along the z axis, that is, f5(1, 0, 0)T. Following the method introduced in ref. 14, a magnetic field Bðr,t~bqðxx^zy^y{2z^zzBzðt^z is applied, where bq.0 is the strength of a quadrupole field gradient and Bz(t) is a uniform bias field. The magnetic field zero is initially located on the z axis at z~Bzð0=(2bq)?Z, where Z is the axial Thomas–Fermi radius of the condensate. The spin rotation occurs as Bz is reduced, drawing the magnetic field zero into the region occupied by the superfluid.

  10. Re:Contradicts current theory? by meta-monkey · · Score: 5, Funny

    So you're saying there's a chance...?

    --
    We don't have a state-run media we have a media-run state.
  11. Re:Contradicts current theory? by breech1 · · Score: 4, Informative

    No it doesn't contradict previous theory. The existence of a magnetic monopole would require adding some extra terms in Maxwell's equations: one for magnetic "charge" (the monopole) and one for magnetic "current" (moving monopole) analogous to electric charge and current. (Adjusting Maxwell's equations this way is a popular exercise in advanced undergrad / grad level E&M courses). If your system happened to have a magnetic monopole in it, then you would need to use the equations with the extra terms. You would see some extra effects due to the monopoles, but they would be accounted for. The extra terms would give a nice symmetry to Maxwell's equations, helping to demonstrate that the electric and magnetic field are manifestations of the same phenomena (which isn't clear until you get to special relativity).

  12. These are NOT Dirac Monopoles by Geoffrey.landis · · Score: 5, Informative

    But how many slashdot stories about fusion reactors, methanol fuel cells, or flying cars has actually been more than investor fleecing vaporware?

    These are not actually Dirac monopoles. These are magnetic quasiparticles that behave in a way that simulates Dirac monopoles.

    The Ars Technicha article has the best explanation:
    http://arstechnica.com/science...
    Emphasis mine:
    "Since we can't seem to find one, though, some researchers decided to emulate monopole behavior using an analogous quantum system. They used a Bose-Einstein condensate: a collection of very cold atoms that behaves like a single quantum system."

    --
    http://www.geoffreylandis.com
  13. Re:Ha the science publishers will be all over this by iggymanz · · Score: 4, Informative

    no, that equation still holds with no known exceptions.

    summary is wrong, no monopoles were produced, just a formation that in some ways resembles one but is not a magnetic source or sink.

    really, the sensationalist nonsense of half of slashdot's headings needs to stop