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Uncertainty should be called as unpredictability

  1. Nov 7, 2011 #1
    it should be called as unpredictability rather than uncertainty principle because the event is certain but we cannot predict it.
     
    Last edited by a moderator: Nov 7, 2011
  2. jcsd
  3. Nov 7, 2011 #2
    Re: uncertainty

    You've got my vote.
     
  4. Nov 7, 2011 #3
    Re: uncertainty


    this is related to the philosophy of quantum mechanics , because according to quantum theory if we can't predict the event exactly with the help of any theory or equation the event then will be uncertain.

    The uncertainty there is related to the nature of the universe not to the tools we use to measure commutative quantities.

    Mathematics in quantum mechanics is the first step , then physics comes later, so when mathematics can't predict an event exactly , this event will be not certain.
     
    Last edited: Nov 7, 2011
  5. Nov 7, 2011 #4

    DrChinese

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    Re: uncertainty

    Is there any evidence to support your statement? Because I know of none.
     
  6. Nov 7, 2011 #5
    Re: uncertainty

    This is not correct according to QM. You can only speak of things that you can measure. Since you cannot know what the event is until you measure it, and you cannot be certain of the outcome of the measurement until you perform it, there is no certain event.
     
  7. Nov 7, 2011 #6
    Re: uncertainty


    Yes

    the new suggested name for uncertainty might be suitable for if we used classical mechanics (Newtonian physics ) , because events would have been inevitable and could be predicted completely (supposing we have the equations and mathematics which can solve them)
     
    Last edited: Nov 7, 2011
  8. Nov 7, 2011 #7
    every one will give example of tossing a coin.but the coin shows head or tail according to physical law of force given for tossing. if you have a good machine, we can give desired force and get head or tail that is what ever we want. it is not uncertain event, if we measure exact force. similarly, sub atomic particles. so, i think we have to change the philosophy of physics.
     
  9. Nov 8, 2011 #8
    These days its often referred to as "Indeterminacy" instead of uncertainty.

    It is a principle, not a law, and merely states that the system is undefined until measured. Since there is no agreed upon metaphysical foundation it is undefined until measured.

    Now if you really want to get into semantics and splitting hairs you could also claim Indeterminacy is supernatural because it can defy local physical laws.
     
  10. Nov 8, 2011 #9

    turbo

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    Still, unpredictability is not a good word. We don't have the means to observe "expected" behaviors as they happen. We have the means to extrapolate from the behaviors of lots of particles (statistically), but that's pretty much the end of the classical regime, IMHO. Uncertainty is not a bad word to describe what happens to classical physics when we start looking at individual particles, or even lots of particles. Their collective behavior is predictable, but their individual behavior is not.
     
  11. Nov 8, 2011 #10
    In the Stern-Gerlach experiment, the silver atoms are all in the same superposition state. According to you, they should all deflect in the same direction, but they don't. Half of them deflect in one direction and half in the opposite direction.
     
  12. Nov 8, 2011 #11
    I like "inconsistency principle" better, because identically prepared systems don't give consistent measurements :)
     
  13. Nov 8, 2011 #12
    Re: uncertainty

    I shall support jayaramas' statement ("it should be called as unpredictability rather than uncertainty principle because the event is certain but we cannot predict it.") while modifying it:

    The event is possible, but cannot be predicted.
     
    Last edited: Nov 8, 2011
  14. Nov 8, 2011 #13
    What exactly do you mean by inconsistent? If you mean it in the logic sense I don't really get your point.

    Indeterminate is kind of wrong because we can determine what are the possible measurements.Uncertainty is just right because that's what the uncertainty principle is all about ,uncertainties.The more certain are about a the less certain we are about b.This does not mean that b is indeterminate since we do actually have some info on b.
     
  15. Nov 8, 2011 #14
    The word "uncertainty" leads to a lot of confusion. Say an electron is moving along, minding it's own business, and we decide to measure position and momentum. The way I (and many many others) interpreted it for the longest time was:

    (measured position - true position)*(measured momentum - true momentum) > h_bar/2

    Obviously this is nonsense, but semantically, the word "uncertainty" suggests this relation. Maybe not to you personally, but for a lot of people, it does. So it would make sense to change the word such that it confuses the least number of people while still being technically correct according to its definition.
     
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