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Uncertainty principle

  1. Mar 18, 2007 #1
    1. The problem statement, all variables and given/known data
    According to Heisenberg Uncertainty principle,
    Del(X)xdel(P) >= h/2(pi)
    But there is also another expression given in my book which is,
    Del(X)xdel(P) >= h/4(pi)
    I asked my lecturer why is it so? She said that, the second expression is obtained from Fourier analysis. But she also said that in calculations, you can use the first one. Which should I use in competitive exams?

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Mar 18, 2007 #2
    The second one is the form given in all modern text books and the one you will be expected to use in your exams.
  4. Mar 18, 2007 #3
    In 1D I believe the lower bound on the product of these uncertainties is your second expression.
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