Scale of uncertainty principle

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Discussion Overview

The discussion centers on the applicability of the uncertainty principle across different scales, particularly questioning its relevance beyond atomic scales. Participants explore interpretations and implications of the principle in both quantum and macroscopic contexts.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions the scale at which the uncertainty principle can be considered, specifically asking about its relevance in non-atomic scales.
  • Another participant suggests that the interpretation of the uncertainty principle can vary, noting its precise mathematical form but cautioning that its extrapolation to macroscopic domains may not be appropriate.
  • A participant references the mathematical expression of the uncertainty principle, indicating that the small value of Planck's constant results in minimal macroscopic effects, which they believe average out.
  • Schrödinger's cat is mentioned, implying a connection to the discussions around interpretations of quantum mechanics and the implications of the uncertainty principle.
  • One participant humorously expresses frustration with the formatting tools for equations while reiterating the uncertainty principle's expression, linking it to the absurdity of certain interpretations like the Copenhagen Interpretation.
  • Another participant reflects on the improbability of large-scale quantum effects, such as the entire solar system appearing elsewhere, suggesting that while theoretically possible, it is practically impossible.

Areas of Agreement / Disagreement

Participants express differing views on the applicability and interpretation of the uncertainty principle across scales, indicating that multiple competing perspectives remain without a consensus.

Contextual Notes

Some limitations noted include the dependence on interpretations of the uncertainty principle and the unresolved nature of its implications in macroscopic contexts.

rahuljayanthb
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in what scale can we consider the uncertainty principle?can it be considered in the non atomic scale?
 
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I would say: that will depend on what is the meaning (or interpretation) that you are going to put it. Uncertainty principle in its mathematical form has a very precise probabilistic meaning. It is valid for mixed states as well as for pure states. But in physics its interpretation goes far beyond the simple inequality. Some of this extrapolation may not be appropriate in the macroscopic domain, it may lose its meaning.
 
\Delta x\, \Delta p \ge \frac{\hbar}{2}

huh... I thought there was a way to insert equations here, but I'm too dull to find it.

Anyway, according to wiki (http://en.wikipedia.org/wiki/Uncertainty_principle)
The principle states that a minimum exists for the product of the uncertainties in these properties that is equal to or greater than one half of the reduced Planck constant (ħ = h/2π).

And Planck's constant is pretty danged tiny, so macroscopic effects are very minimal. I like to think of them as being averaged out in a wash of counter-uncertainties.
 
Schrodingers cat
 
Just had to try it...

[tex] \Delta x\, \Delta p \ge \frac{\hbar}{2}[/tex]

Hah. Thanks! I thought there was a little clicky-button on the editor for it, but lost patience with waiting for the tool-tits to popup and explain things to me.


To continue beating the dead Schrödinger cat thing: That old chestnut was invented to show how absurd the Copenhagen Interpretation could be (IIRC). While there are places where quantum weirdness can affect classical results the general case is one of "averaging out". The usual thrust of these scale questions is: Could the entire solar-system suddenly appear on the other side of the galaxy? And the answer is: Yes, but it's so improbable as to be impossible.
 

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