Talk:Complementarity (physics)

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[edit] Duality

The section on Englert-Greenberger duality is due to User:Drezet; thought I'd mention that here, since the edit history does not make clear that this was copied here from Afshar experiment. Thanks Drezet! linas 01:56, 7 February 2006 (UTC)

I have hived it off into its own page since complementarity is Bohr's creation and the later Englert-Greenberger duality is a much more focussed application of this. --Michael C. Price talk 14:53, 13 July 2006 (UTC)

[edit] "simultaneously"?

Is the word "simultaneously" correct, in view of the Ashaf experiment? In that experiment an attempt is made to measure such properties of a single photon one after the other, which thus would not test a simultaneous measurement claim - but I wonder if that word belongs here. An exact citation of Bohr would be most beneficial. Harald88 10:40, 29 April 2006 (UTC)

The Heisenberg uncertainty relationship applies to the simulatneous measurement of position and momentum (or more generally of any two conjugate variables). Most physicists interpret complementarity as being enshrined in the HUP, but a more exact quote would be helpful. --Michael C. Price talk 18:43, 28 October 2006 (UTC)

[edit] Quote from Bohr's assistant?

"There is no quantum world. There is only an abstract physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature."
I recall this quote being from Bohr's assistant rather than from Bohr himself. Not that it really matters I suppose. --Carl A Looper 00:38, 22 December 2006 (UTC)
The assistant is quoting Bohr.--Michael C. Price talk 08:08, 22 December 2006 (UTC)

[edit] Is this principle now under debate?

Having just read this: Physicists Modify Double-Slit Experiment to Confirm Einstein's Belief I'm wondering whether the principle of complementarity should be noted as being under debate? Not being an expert I'm open to correction and enlightenment. --210.175.46.205 04:05, 13 March 2007 (UTC)

The "article" you cited is actually a press release by the researcher's university publicity office. In fact, Foundations of Physics, regardless of who's on its editorial board, is well known for publishing loads of crackpot articles (in addition to some reasonable, thought-provoking ones). If every theory that was challenged in this journal had to be flagged as being under debate, then that would include pretty much everything in physics, ever (every aspect of special relativity, general relativity, quantum mechanics, astronomy, etc.). As of now, this is very, very far from being under debate. Steve 20:06, 31 July 2007 (UTC)

[edit] Impossibility of superpositions ?!

I provide obviously wrong statement from the article:

"This means that there is a limitation on the precision with which an electron can possess (i.e., manifest) position, since an infinitely precise position would dictate that its manifested momentum would be infinitely imprecise, or undefined (i.e., non-manifest or not possessed), which is not possible."

This is completely wrong. What Heisenberg inequality show is that -- if the position is localized in space, then the momentum is superposed! Inversely, if the momentum is well defined, the particle is superposed at many locations in space. So the "uncertainty" is NOT criterion for impossibility, but shows that there is some minimal requirement for quantum superpositions! If one of two non-commuting observables is well measured, then its complementary observable will be superposed. Danko Georgiev MD (talk) 09:18, 20 February 2008 (UTC)