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Reduction in Heisenberg uncertainty

  1. Jul 8, 2006 #1
    I am writing this on the curiosity of the results of a theoretical experiment. Imagine a photon moving thorugh space. It is moving freely through three dimentions and time. Using the Lorentz contraction we can only know approximately where it will be in 3 dimentions for a given time and speed. Now imagine taking 2 panes of glass that are infinitely smooth, and sandwiching the photon between them. The panes are the exact width of the photon apart, so now the photon can only move in two dimentions and time. Let's take it one step further and bring two more sides in so the photon can now only move in one dimention and time. Imagine it's in a tube the
    exact circumference of the photon itself. How would this photon move in one dimention? Could it's exact location for a given time and speed now be predicted? :surprised
  2. jcsd
  3. Jul 8, 2006 #2


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    There is a boatload of problems here in which you have to suspend other physics to sustain what you want to do:

    1. What is the "size" of a photon? It's wavelength? Do you realize what would happen if you make light pass through a slit comparable to its wavelength?

    2. Why would "infinitely smooth" glass matter? Just so it is 100% reflective? Not possible unless you want to change the mass of electrons to zero (which would change our universe completely).

  4. Jul 10, 2006 #3


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    People have tried to make thought experiments like this before, by somehow constraining double slit experiments and thinsg of that nature. Wormholes, infinitely long strings, domain walls, planck scale physics constraints (ad nauseum)

    Something always goes wrong though, much like the old perpetual motion things. Often unitarity is violated somewhere microscopically, or the classical recipes violate some energy condition etc etc.
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