Talk:Quantum mechanics/Archive 2

message: The majority of this discussion occurred in 2004, please do not edit this archive. - RoyBoy 800 00:40, 20 Jun 2005 (UTC)

message: I just turned in a lab report on the Ramsauer-Townsend effect and finished up the article on it I started a week ago. the effect is discussed in quite a few quantum mechanics textbooks and is an example one phenomenon you need quantum mechanics to explain (specifically, the wavelike nature of the electron). i worked on it as part of a course, an introduction to quantum mechanics for junior-year physics undergraduates. is there another page i should edit to add a link to it?
--Blick 08:06, Feb 26, 2005 (UTC)
:There are hundreds of phenomena that you need quantum mechanics to understand. I don't think making such a list is particularly useful. If you are interested in a topic, just work on it and link to quantum mechanics; there is no need for a return link. -- CYD
Perhaps some mention of the problem that inspired Planck to invent Quantum Mechanics is in order. IIRC, physicists were trying to figure out what electromagnetic waves were in an oven that had a certain amount of heat in it. They knew that an integer multiple of the wavelength of the light in the oven would have to equal one of the dimensions of the oven, but every time they tried to figure it out, they ended up concluding that the oven had infinite energy in it. Planck was able to find the answer by assume that the energy in an electromagnetic wave was quantised such that E ∝ f. This went directly counter to the classical mechanics assumtion that E ∝ Amplitude.
:not quite, in classical mechanics it's proportional to both the square of the amplitude and the square of the frequency 63.205.40.243 05:12, 8 Jan 2004 (UTC)
thread_title:  Where should I add a link to an example of quantum phenomena? 

message: I saw that this was discussed before, but nevertheless I was not happy to see that "quantum physics" and "quantum theory" are listed as simply synonyms of quantum mechanics, when often they are used to make a distinction. I added a couple of sentences to this effect to the introduction,
telling that someotime they are meant to mean something slightly different...please check and modify, but, please, dont let them again as simply alternative names.--AstroNomer 09:28, Jun 2, 2004 (UTC)
Are you saying that quantum physics is a superset and quantum theory is a subset? Bensaccount 16:59, 13 Jun 2004 (UTC)
thread_title:  quantum physics, quantum theory 

message: My last edits reflects my view that this is the best way to present a scientific theory:
* start with the limitations of previous theories (here: electromagnetism): no quantization and no wave-particle duality
* describe the theory, and how it overcomes the limitations of the previous theory (this is the bit that I saw missing, and corrected)
* describe predictions of the new theory (here: entanglement)
* describe limitations of the new theory
Pcarbonn 12:12, 11 Jul 2004 (UTC)
replies: text: I have now restructured the article along those lines.  See Wikipedia:WikiProject Science to further discuss this. Probably needs some more work though.  Pcarbonn 19:46, 16 Jul 2004 (UTC)

text: Sorry, this was accidental.  I had to move quite a few things around, so this may have happened.  I would suggest your insert it again in the "Quantum effect" sub-section.  (you know this subject better than me) Pcarbonn 19:04, 18 Jul 2004 (UTC)
thread_title:  proposed structure for the article 

message: I have a question about these two sentences:
"This phenomenon is called entanglement and its difference from ordinary correlation is described by Bell's inequality. Experimental violation of Bell's inequality are, despite the presence of loopholes, currently accepted as one of the major verifications of the quantum theory."
If the difference of the quantum phenomenon (entanglement) and the normal correlation is described by the Bell's inequality, then its verification would be the verification of the quantum theory, wouldn't it? Or better the "ordinary correlation described by Bell's inequality" should be written.
Pál 23:51, 14 Jul 2004 (UTC)
thread_title:  quantum entanglement, Bell's inequality 

message: I think the subsection "Quantum mechanical effects" has a false suggestion. Say thinking of the momentum-spatial coordinate uncertainty principle it suggests, that of of them is particle like variable, and the other is wave like. There are two basic representations, the Schrodinger (spatial coordinate) and the Heisenberg (momentum) representation of QM, and both have the wave-particle duality. The relativistic theory prefers the momentum representation, but it does not mean, that either the wave or the particle behaviour is lost. The propagation is wave like and the creation and annihilation is particle like. User:Hidaspal 20:30, 15 Jul 2004 (UTC)
replies: text: Fine.  In the section 'Quantum mechanical effects', I would really like to have an explanation on how those effects are explained by the theory, e.g. by referring how the wave function behaves when those effects are observed.  Otherwise, the section just explains what wave-particle duality is, but we can find that in the corresponding article. I'm sure many people would find this interesting.  Unfortunately, I don't know enough myself to explain it correctly.  Could you help ? Pcarbonn 19:26, 16 Jul 2004 (UTC)
thread_title: Wave-particle duality vs uncertainty principle

message: I just tried to follow the guidelines at Wikipedia:Captions to revise the caption on this page - please check it for correctness and make improvements as needed.  (The caption that was there didn't mean much of anything to me, and I studied orbitals in chemistry class a decade ago, so I thought it worthwhile to translate to make the picture more meaningful to the masses.) -- ke4roh 18:39, Jul 30, 2004 (UTC)
:I have a problem with the word orbit which implies the electron is a satellite of the nucleus, moving in an orbit - if that were so, this charge would be accelerating, hence radiating energy, which is not observed; in a sense, the electron is everywhere the probability density shows it to be, simultaneously, but it takes an observation to place it. I am replacing the word orbit with orbital Ancheta Wis 07:58, 31 Jul 2004 (UTC)
thread_title:  Caption 

message: Has the double-slit experiment been superseded by another explanation which actually does not appear here? I fancied it was one of the clearest introductions to the subject, but as of 1 Aug 2004 the word "slit" does not appear in the article... ?? Pfortuny 09:43, 1 Aug 2004 (UTC)
thread_title:  Funny that there is no slit here 

message: Having just read the article, I think the words operator and wavefunction both deserve some unraveling.  These concepts may be intuitive to a physicist, but they are not intuitive to the general public.  I don't mean that their explanations need to be mathematically rigorous, but they should describe what these terms mean.
Also, I would love to have the image of hydrogen probability density functions described further.  When I was in high school, I saw pictures of these in my physics and chemistry textbooks, and now they make a lot more sense to me.  The wavefunctions associated with these pdf's form an orthogonal set, and that is a thing of beauty.
The History section looks and reads like it was tacked on.  The history of quantum mechanics is an amazing topic, one that probably deserves its own article.  The connection between these early experiments and their role in developing quantum mechanics is de-emphasized in this article.  Some important experiments to add: 
* Discovery of the electron
* Franck-Hertz experiment
* Young's double-slit experiment, and as applied to electrons (agree with above comment)
Another thing I don't like is the statement about quantum mechanics being incompatible with general relativity in the Interactions... section.  While this is true, could someone please explain why it is true?  This is a claim that is made in lots of popular accounts of physics, but it is hardly ever backed up.  What are the fundamental assumptions of quantum mechanics that are violated by general relativity?  This has never been explained well to me. --Hfs 01:23, 2 Aug 2004 (UTC)
replies: text: Notice that the Young diffraction experiment has been tested with up to buckyballs, which are quite large... Pfortuny 21:19, 7 Aug 2004 (UTC)
thread_title:  Unraveling some jargon and Historical development 

message: This text was recently added by an anonymous user. There are several things that are suspect. The style is not quite encyclopedic and googling for names mentioned in it returns very few google hits. (None for "Nikola Kalitzin", 8 hits for "Josiph Rangelov").I removed it for the time being, comments from experts in this area are welcome. Andris 20:45, Sep 21, 2004 (UTC)
What is the physical cause for quantum behaviour of micro particles? Why we use a wave equation of Schrodinger for description of quantum behaviour of micro particles instead to use a corpuscular equation of Hamilton-Jacoby, descripteng the classical behaviour of macro particles? What is a diference between these two equations? What is a difference between classical trajectory and quantum wave function?
 
It 1952 year Nikola Kalitzin supplements the electromagnetic interaction between the electron electric charge and the electric field of the zero-point electromagnetical fields to classical motion equation of same electron, taking in consideration the Lorentz' friction force of its charge. In this wаy Kalitzin first have obtained why coordinate and impulse of such electron don't comutate. In 1954 year A.A. Sokolov supplements the oscillation force to the electromagnetic interaction whitout to ezplain the cause for this and have obtained more correctly commutation equation.In 1980 year Josiph Rangelov explains what means Kalitzin's takinkg in consideration of the electromagnetic interaction between the electric charge of an  electron and the electric field of the zero-poind electromagnetic fields of the fluctuating vacuum and Sokolov's oscillation force. In this way Rangelov explains that the quantum motion of the quantized electron is a sum of two motions : in first the classical motion and in second the stohasstic motion as a result of the electromagnetic interaction of its electric charge and the electric field of the vacuum fluctuations. In results of this the narrow path of the classical corposcule turns in wide highway of the quantum micro particle and classical determinism turns in quantum probability. Therefore if we add the kinetical energy of the micro particle stohastic motion to classical Hamiltonian-Jacoby motion than we would obtain the quantum Schrodinger equation. Therefore quantized micro particles parameters of motion have dispersion instead definite values.
In second Rangelov explain that the electric charge of the reletivistic electron participates in some inner motion, called by Shcrodinger as Zitterbewegung. This inner motion creates the own electromagnetic filds, the own magnetic dipole moment and its inner mechanical angular moment, called spin.
:Interesting that all the google hits for Josiph Rangelov seem to be posts from him to a blog or forum. Could this be a case of self-promotion? -- Tim Starling 02:48, Sep 22, 2004 (UTC)
The text in question definitely isn't standard quantum mechanics. --Matt McIrvin 01:19, 25 Sep 2004 (UTC)
thread_title: Suspect text

message: :The phrase "quantum physics" was first used in Johnston's Planck's Universe in Light of Modern Physics.
Do we have a reference for this claim? I can find only three pages in Google that make this claim, and they are all different versions of this Wikipedia article!--Susurrus 05:02, 17 Dec 2004 (UTC)
thread_title:  Phrase "quantum physics" 

message: I just created the quantum darwinism article. Could someone more knowledgable than I please mention it in quantum mechanics and any other relevant articles. Much thanks. --RoyBoy 22:20, 27 Dec 2004 (UTC)
thread_title:  Quantum darwinism