This shows you the differences between two versions of the page.
Both sides previous revision Previous revision Next revision | Previous revision | ||
advanced_notions:uncertainty_principle [2018/05/18 07:30] 77.10.73.75 [Why is it interesting?] |
advanced_notions:uncertainty_principle [2018/07/26 17:56] (current) 77.177.199.249 [FAQ] |
||
---|---|---|---|
Line 33: | Line 33: | ||
<cite>https://www.scientificamerican.com/article/common-interpretation-of-heisenbergs-uncertainty-principle-is-proven-false/</cite> | <cite>https://www.scientificamerican.com/article/common-interpretation-of-heisenbergs-uncertainty-principle-is-proven-false/</cite> | ||
</blockquote> | </blockquote> | ||
+ | |||
+ | <blockquote>Bohr, for his part, explained uncertainty by pointing out that answering certain questions necessitates not answering others. To measure position, we need a stationary measuring object, like a fixed photographic plate. This plate defines a fixed frame of reference. To measure velocity, by contrast, we need an apparatus that allows for some recoil, and hence moveable parts. This experiment requires a movable frame. Testing one therefore means not testing the other. <cite>https://opinionator.blogs.nytimes.com/2013/07/21/nothing-to-see-here-demoting-the-uncertainty-principle/</cite></blockquote> | ||
---- | ---- | ||
Line 67: | Line 69: | ||
\begin{equation} \sigma_A \sigma_B \geq \big | \frac{1}{2i} \langle [A,B] \rangle \big|^2 . \end{equation} | \begin{equation} \sigma_A \sigma_B \geq \big | \frac{1}{2i} \langle [A,B] \rangle \big|^2 . \end{equation} | ||
+ | See also | ||
+ | |||
+ | * [[https://arxiv.org/abs/quant-ph/0608138|The certainty principle (review)]] by D. A. Arbatsky | ||
---- | ---- | ||
Line 120: | Line 125: | ||
<tabbox FAQ> | <tabbox FAQ> | ||
+ | |||
--> Is there a time-energy uncertainty relation?# | --> Is there a time-energy uncertainty relation?# | ||
Line 166: | Line 172: | ||
<-- | <-- | ||
- | --->What's the origin of the uncertainty? # | + | -->What's the origin of the uncertainty?# |
<blockquote>Quantum mechanics uses the generators of the corresponding symmetry as measurement operators. For instance, this has the consequence that a measurement of momentum is equivalent to the action of the translation generator. (Recall that invariance under translations leads us to conservation of momentum.) The translation generator moves our system a little bit and therefore the location is changed.<cite>Physics from Symmetry by J. Schwichtenberg</cite></blockquote> | <blockquote>Quantum mechanics uses the generators of the corresponding symmetry as measurement operators. For instance, this has the consequence that a measurement of momentum is equivalent to the action of the translation generator. (Recall that invariance under translations leads us to conservation of momentum.) The translation generator moves our system a little bit and therefore the location is changed.<cite>Physics from Symmetry by J. Schwichtenberg</cite></blockquote> | ||
<-- | <-- | ||
- | |||