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Tying Knots With Light

Posted by Soulskill on from the knot-easy dept.

thedreadedwiccan points out a summary of a recently released physics paper about tying knots with light. A pair of researchers showed that a relatively new solution to Maxwell's equations allows light to be twisted into stable loops. They are designing experiments to test the theory now, and it could have a big impact on fusion technology. The paper's abstract is available at Nature, though a subscription is required to see the rest. Quoting: "In special situations, however, the loops might be stable, such as if light travels through plasma instead of through free space. One of the problems that has plagued experimental nuclear fusion reactors is that the plasma at the heart of them moves faster and faster and tends to escape. That motion can be controlled with magnetic fields, but current methods to generate those fields still don't do the job. If Irvine and Bouwmeester's discovery could be used to generate fields that would send the plasma in closed, non-expanding loops and help contain it, 'that would be extremely spectacular,' Bouwmeester says."

3 of 125 comments (clear)

  1. The Real Question is.... by cychem1 · · Score: 3, Interesting

    The real question is was a silver hammer necessary?

  2. Ok, questions by Marrow · · Score: 3, Interesting

    1. How do you bend light without passing it through matter or using a grav field that will crush the experiment?

    2. If they can bend light, why are we using electron beams for crt's?

    3. If you could build loops of light can they be modulated to store information and read it back again?

  3. Re:The summary misses the key point by sedm1143 · · Score: 3, Interesting

    Yes, but plasma consists of charged particles which can be trapped by electro-magnetic fields. Light (in the wave picture at least) is simply an electro-magnetic field, so if you can tie light in loops theoretically you can also trap the plasma too. Now I agree that applications are a long way off - this is a theoretical paper so presumably no one has (intentionally) done it yet. If this proves interesting someone would have to build/modify an existing experiment to create and detect the phenomenon, and then there's a long way from there to a practical device, assuming it actually proves technically feasible.