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minduploading.org News: Perfect Lenses?

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  • Randal Koene
    Dr. Pendry postulates the properties of lenses made with materials that have a negative refractory index and subsequently may permit the construction of
    Message 1 of 1 , Nov 11, 2000
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      Dr. Pendry postulates the properties of lenses made with materials that have a negative refractory index and subsequently may permit the construction of perfect lenses at any wavelength of light. If this works, it could be of hugh value to whole brain emulation. Imagine extreme precision at long wavelengths! This could reduce the damage to a sample, possibly even aid in the development of non-invasive high-resolution scanning devices.

      "Lens design: A sharper focus"

      "THEORETICAL physicists have a knack of asking ``why not''
      Antimatter was discovered because a theoretician called
      Paul Dirac saw that one of his equations had two solutions: one
      with a plus sign that predicted normal negatively charged
      electrons, the other with a minus sign that predicted a
      curious positively charged beast."

      "In similar vein, John Pendry of Imperial College, London has been
      asking what happens if a material's refractive index, which
      measures how much it bends a ray of light or other form of
      electromagnetic radiation, is negative instead of positive --
      an idea that folk familiar with practical optics might dismiss as
      absurd."

      "Dr Pendry's calculations for a material with a negative
      refractive index, rather like Dirac's for the electron, have two
      solutions -- and the second allows near-field waves to grow
      instead of decaying. In the right circumstances this effect can
      exactly balance out the decay, ensuring that all the information
      is restored in a perfect image of the source. The wavelength of
      visible light is a fraction of a millionth of a metre, which
      sets a resolution limit for conventional optical microscopes.
      But with negative-refractive-index lenses, this limit could be
      removed."

      "Earlier this year, Sheldon Schultz at the University of California,
      San Diego, showed that a specially designed material made of wires
      and rings had a negative refractive index in the microwave region.
      Meanwhile Dr Pendry and his colleagues at Hammersmith Hospital in
      London, along with GEC Marconi, an electronics company, have
      designed a negative-refractive-index lens for radio waves on the
      same principles."

      "The technique remains unproven, but early efforts by Dr
      Pendry and his colleagues seem promising. And Dr Pendry already
      has ideas about how to build lenses that would do the same job
      in the optical region. For generations of scientists, the
      diffraction limit was seen as a fundamental barrier to progress
      in optics, so news of perfect lenses will come as a shock
      to some. But then, so did antimatter."


      Complete Story: http://www.economist.com/science/displayStory.cfm?Story_ID=417791
      _______________________________________________________________________
      RANDAL A. KOENE
      Neural Modeling Lab, Department of Psychology - McGill University
      randalk@..., www.psych.mcgill.ca/perpg/stds/rk/
      minduploading.org, Lab:(514)-398-4319, Home:(514)-767-6406
      _______________________________________________________________________
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