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Uncertainty Principle concept

  1. Feb 13, 2013 #1
    I'm trying to understand the uncertainty principle.

    ΔxΔp >= h/4∏

    from my understanding of the concept, its not possible to know the value of the position and the momentum simultaneously. yet the problems that i see floating around on the internet seem to just plug in values for mass and velocity to solve for position.

    i understand that the answer yielded would be

    Δx >= whatever

    showing that there is uncertainty in the value of change in position.

    is that all there is to it? or am i missing something here?

    edit - i'm also trying to teach myself about Schrödinger's equation but the mathematics involved seem too complex.
  2. jcsd
  3. Feb 13, 2013 #2
    here is a very simple example of how to use the uncertainty equation:
    Last edited by a moderator: Sep 25, 2014
  4. Feb 13, 2013 #3
    I don't know. The principle was mentioned in my chemistry course. I had a previous familiarization with the concept so I just googled some problems being solved.
  5. Feb 13, 2013 #4
    The link cleared it up. Thanks.
  6. Feb 13, 2013 #5
    also, just to clear you understanding - the more you know about position, the less you know about momentum. and when they say "its not possible to know the value of the position and the momentum simultaneously" they really mean "its not possible to know the exact value of the position and the momentum simultaneously" So lets say you know fairly accurately the position of your electron - the uncertainty in its momentum will be very large.
  7. Feb 14, 2013 #6


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    The HUP in its precise mathematics formulation is not about our knowledge of position x and momentum p, it's about the impossibility to attribute x and p to a quantum state with higher precision. So he HUP does not only say that we cannot know (nor measure) x and p with higher precision, but that in a general quantum state the particle cannot have auch x and p.
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