Slashdot Mirror


"Overwhelming" Evidence For Magnetic Monopoles

Thorfinn.au sends along big physics news: magnetic monopoles have been detected at low temperatures in "Dirac strings" within a single crystal of Dysprosium Titanate. Two papers are being published today in the journal Science and two more on arXiv.org, as yet unpublished, provide further evidence. "Theoretical work had shown that monopoles probably exist, and they have been measured indirectly. But the Science papers are the first direct experiments to record the monopole's effects on the spin-ice material. The papers use neutrons to detect atoms in the crystal aligned into long daisy chains. These daisy chains tie each north and south monopole together. Known as 'Dirac strings,' the chains, as well as the existence of monopoles, were predicted in the 1930s by the British theoretical physicist Paul Dirac. Heat measurements in one paper also support the monopole argument. The two, as yet unpublished, papers on arXiv add to the evidence. The first provides additional observations, and the second uses a new technique to determine the magnetic charge of each monopole to be 4.6x10-13 joules per tesla metre. All together, the evidence for magnetic monopoles 'is now overwhelming,' says Steve Bramwell, a materials scientist at University College London and author on one of the Science papers and one of the arXiv papers."

9 of 256 comments (clear)

  1. "I maintain nonetheless..." by Arancaytar · · Score: 3, Insightful

    "...that yin-yang dualism can be overcome. With sufficient enlightenment we can give substance to any distinction: mind without body, north without south, pleasure without pain. Remember, enlightenment is a function of willpower, not of physical strength."

    -- Chairman Sheng-ji Yang, Essays on Mind and Matter

    So, can haz magtube now plz?

  2. Re:a magnetic monopole is like a one-sided coin: by anarchyboy · · Score: 5, Insightful

    Yea like that electric charge nonsense, you can't have a particle with a single electric charge! that'd be crazy whatever it is will allways have another side with the oposite charge!

  3. Re:a magnetic monopole is like a one-sided coin: by CensorshipDonkey · · Score: 4, Insightful

    there's no such thing as a monopole. whatever it is, will have another side. and on that other side, there's the magnetic field lines, going on their merry way. a magnet is just atoms lined up in a certain way. are you telling me you can have one-sided atoms?

    I think the stupidity is yours. Magnets are not just atoms lined up, atoms themselves have magnetic poles. In fact, the components of atoms (such as electrons) have magnetic poles as well.

    It's perfectly conceivable to think of a point source of just North or South where the field lines radiate outwards in all directions. They would arc toward the nearest magnetic pole of opposite polarity. The diagrams are simple to draw and have been accepted by just giants in the field as Dirac for eighty years. The only question is: do they actually occur?

  4. Re:lo, you have defeated me by anarchyboy · · Score: 5, Insightful

    I know what magnetism is, I also know what a magnetic monopole is, hell I even know what a dirac string is and what a spin glass is. Honestly your argument about coins made no sense at all.

    I was attempting to point out that electric charge also has field lines but that they do not have two sides like a coin, the entire point of the discovery of a magnetic monopole is that it doesn't have two sides in the way that all the other magnetic dipoles we are used to have.

  5. Re:lo, you have defeated me by Abcd1234 · · Score: 4, Insightful

    I'm sorry, but you're going to have to provide your credentials if you want me to accept that you know more about magnetism than four separate physics research teams, two with articles in Science and two more with draft articles on arXiv.org, all of which show evidence of the existence of magnetic monopoles.

    Christ, not to mention Paul fucking Dirac.

    circletimessquare, you have one again exceeded yourself at demonstrating your truly incredible arrogance and stupidity.

  6. Re:lo, you have defeated me by ojustgiveitup · · Score: 3, Insightful

    Sorry son, it is you who have been defeated by your own ignorance and closed-mindedness. You threw out one (dumb, totally invalid and irrelevant) analogy, somebody came back with a very proper analogy to something actually *related* to magnetism, and you shrugged it off as him not understanding magnetism. In fact, your narrow understanding of magnetism with your little coin analogy has been a convenient way to understand the concept for many years...until today. That's the point. Scientists have been researching monopoles for a long time, quite simply because the coin analogy never quite added up - there was no good reason why they *always* came as dipoles, besides that monopoles had never been observed. Now they have been, everything you know about magnets will probably be wrong once more data is gathered, and you will either have to take the scientists' word for it, or you will have continue using inaccurate mental models to make sense out of it for yourself.

  7. Brace yourselves for the onslaught by 140Mandak262Jamuna · · Score: 3, Insightful

    The whole crowd of people selling devices that use Zero Point Energy and magnetic suspension perpetual motion machines and people who write hundred page manuscripts in purple ink arguing why the Second Law of Thermodynamics must be repealed are going to come out of the wood work now.

    --
    sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
  8. I'm a bit confused by this by Bootsy+Collins · · Score: 3, Insightful

    Dirac's argument (and all the field-theoretic) arguments in favor of the existence of magnetic monopoles have had to do with an elementary particle exhibiting those characteristics. Sometimes this is phrased in the terms of a 0-dimensional topological defect, something that would be produced by certain kinds of symmetry breaking; and indeed one of the arguments in favor of cosmological inflation theories was the fact that we don't see fundamental-particle monopoles, and would expect to. Finding one of these guys would be amazing news.

    What these experiements seem to have done, however, is detected the effect of what condensed matter physicists like to refer to as a quasi-particle, akin to the phonon, which is a different thing entirely.

    Or am I missing something?

  9. Re:Practical Impact? by jeffb+(2.718) · · Score: 3, Insightful

    If they were real, physical, isolable monopoles, they might turn out to have some minor applications in energy production. (Yeah, I linked the same article upthread; it's interesting enough to repeat.) The claim is that they would make protons (and neutrons) decay promptly. Of course, if these folks were seeing that kind of monopole, they would have noticed side effects, starting with a sudden inability to keep their samples below 1 K.