Talk:Quantum mechanics/Archive 6

message: 24.91.73.141 plopped http://www.nytimes.com/2005/12/27/science/27eins.html in external links. I suppose the travel of enlightenment seekers is apt to be in the other direction: from the there to here. How can something actually be two contradictory things may be the question. Honest-liar, clod-swoosh, correct-incorrect. Here's a quote from that article: "This fall two Nobel laureates, Anthony Leggett of the University of Illinois and Norman Ramsay of Harvard argued in front of several hundred scientists at a conference in Berkeley about whether, in effect, physicists were justified in trying to change quantum theory, the most successful theory in the history of science. Dr. Leggett said yes; Dr. Ramsay said no." Wouldn't it exact if both were right? The Times links the article to some quotes, for instance: " 'I don't like it, and I'm sorry I ever had anything to do with it.' -- Erwin Schrödinger about the probability interpretation of quantum mechanics". If you can bring yourselves to call the eigenwhosis "discrete value" it might help the jargon averse. Is not precision proven to be unobtainable in a reality sure to be uncertain? Unless it both is and isn't, of course. 207.172.134.175 07:05, 28 December 2005 (UTC)
replies: text: See cat state. --Ancheta Wis 11:13, 28 December 2005 (UTC)
replies: text: Yes, quantum mechanics wouldn't state that a person was honest and a liar or an object was clod or swoosh at the same time. It would rather state that there's a superposition of the person being honest and of him being a liar or that there's a superposition of the object being clod and being swoosh -- or, for that matter, a superposition of the cat being alive and being dead. Quantum mechanics routinely deals with superpositions of situations, and it is forced to do so by results as seen in the double-slit experiment. Many-worlds theory takes this idea at face value. Ancheta gave the mathematical notation for superpositions. --DenisDiderot 13:18, 28 December 2005 (UTC)
replies: text: F. Lindner, M. G. Schätzel, H. Walther, A. Baltuska, E. Goulielmakis, F. Krausz, D. B. Milosevic, D. Bauer, W. Becker, G. G. Paulus in Attosecond double-slit experiment Physical Review Letters 95, 040401 (2005) conclude "The observation of interference and its absence at the same time for the same electron (emphasis added) is a beautiful demonstration of the principles of quantum mechanics," and (oh, by the way) attosecond interferometry will have practical applications. The website of Gerhard Paulus explains the experiment. "Superposition" is certainly more firmly established than Jung's Pleroma; note there, "time as relative concept; all historical processes complemented by 'simultaneous' existence in the Bardo or pleroma". Reality is pretty weird. 207.172.134.175 22:38, 28 December 2005 (UTC)
replies: text: Roger Penrose's omnium appears to be the Bardo or Pleroma, as well. By the way, Penrose, a mathematician who happens to be vitally interested in physics, as evidenced by his new book Road to Reality (I recommend it; it has a very nice discussion of the mathematical concept called a connection as well as a graphic representation for tensor notation; -- his wife illustrated the book) has found a viewpoint that more firmly supports GR than QM. So you might discover that this thread is currently leading to Penrose and GR, as far as I can tell, rather than to QM. --Ancheta Wis 18:02, 29 December 2005 (UTC)

text: But hold on, this image  which resembles the vortex distribution of a bose-einstein condensate shows there is some application of Penrose's ideas to QM. It closely resembles the symmetries in a BEC bose-einstein condensate picture that Eric Cornell recently displayed at a public lecture of his - his picture was blue with each superfluid vortex a dark spot corresponding to a polyhedron in the Penrose tiling, except that the spots followed a hexagonal distribution rather than the pentagonal distribution you see. --Ancheta Wis 20:44, 29 December 2005 (UTC)
replies: text: Amazon said they'll ship The Road to Reality to me next year. Congrats on your sysopship - don't let them overwork you. GR & QM facets of the same thing? If so, the connection is opaque to the duality mired (i.e. all of us). Happy New Year! Anon user 207.172.134.175 generally also me, Metarhyme 17:52, 30 December 2005 (UTC)

text: Thank you! Like the old Texas Rangers, who made their star-shaped badges from 5-peso silver coins, I formed an 8-pointed badge out of an Aztec calendar. And a happy J2000+6 to you! --Ancheta Wis 19:46, 30 December 2005 (UTC)
thread_title:  25 Dec 05 is over 

message: *By the way show given as :
:-\frac{\hbar^{2}}{2m}[(\frac{d^2}{dx^2}+\frac{d^2}{dy^2}+\frac{d^2}{dz^2}+\frac{d^2}{dt^2})\Psi(x,y,z,t)]+V\Psi(x,y,z,t)=E\Psi(x,y,z,t)
Schrödinger equation's coefficient of the extreamly left can be〝operated〞to 2 parts.
One is for Uncertainty Principle exactly well.\Longrightarrow \frac{\hbar}{2} which is good for the limited value of the product by \Delta P and \Delta X.
The other is for \frac{\hbar}{m},recently without any sense in physics well.
--HydrogenSu 09:58, 30 January 2006 (UTC)
replies: text: The left side is just Kinetic + Potential energy. The left half of the left side is Kinetic energy, the V half of the is Potential energy, for a single particle. If you use the heuristic that 'Observables (Kinetic + Potential energies) are Operators', you get the right side of the Schrödinger equation. --Ancheta Wis 10:55, 30 January 2006 (UTC)
replies: text: Can we take apart by seprated operation on \hbar \over 2m without any reasons of "Observables or not"? (Just in Math to seperate them away?)Thank you,this is my question after reading your reply.--HydrogenSu 18:10, 30 January 2006 (UTC)

text: The Schroedinger equation is non-relativistic.  There are relativistic quantum mechanic equations such as the Klein-Gordon Equation.  The left side could be seen as the hamiltonian operator on the function and the left side is the scalar energy times the function.  This equation therefore is saying that the energy is the eigenvalue.  What you also may be confused is that it can also be shown with a time derivative in place of E.  This is also correct where the operator corresponding to E is a first order time derivative, this is also seen in classical mechanics but the algebraic structure is different between them.  Time and space are not the same, although they appear to be.  Time in non-relativistic quantum mechanics is nothing but a parameter, like the affine parameter in general relativity.  It has no significance other than being a parameter.  The position however is an operator.  it is not evident here and in this format since using wave functions is very clumsy in terms of quantum mechanics.  the second derivative with respect to space is the momentum operator.  its hard to judge what is a parameter and an operator by mearly looking at an equation.  i hope that made some sense --Blckavnger 20:55, 17 November 2006 (UTC)
thread_title:  OPERATION to Schrödinger equation 

message: I started the article a while back and placed a link here; I'm sure it was removed for a good reason... but couldn't it be linked to somewhere in this article? And or going in the Quantum topic template? - RoyBoy 800 08:15, 30 January 2006 (UTC)
thread_title:  [[Quantum darwinism]] 

message: There is so much discussion here that my edit comments may not be considered sufficient explanation for my changes.
"Quantum mechanics uses complex number"  The probabilities are not part of the mathematical formulation.  The formulation is in terms of complex wave functions, and so forth.
"These are related to classical physics and ordinary language largely with the use of probability."  This is essential to interpretation of classical physics and ordinary language in terms of quantum mechanics.  Encyclopedia readers will be looking at it from the other direction, but this wording can be read from the classical point of view also.
"Newton's laws of motion"  Gravity has little to do with atoms.
"obeys" qm "arises from" all observations of nature.
"the classical position" in qm, things have wave functions.  "position", in the sense of an exact position of a particle is a uniquely classical concept.  (Position doesn't seem to have a good link so maybe I will remove the link.)
"instead of describing"  This change may not be necessary, but is based on the same argument as above.
"Therefore, quantum mechanics, translated to Newton's equally deterministic description, leads to a probabilistic description of nature."  I expect a lot of argument about "equally deterministic", but the time dependent Schrödinger equation is first order in time, which makes it explicitly deterministic.  The probabilities do not arise until the classical approximation is first used.  The (new) probabilities belong only to the relation between qm on one hand and classical physics and ordinary language on the other.
Perhaps "Newton's equally deterministic description" may be inadequate here, because it is not really his view, it is the view of everyone before Schrödinger and Heisenberg.
David R. Ingham 08:59, 12 February 2006 (UTC)
replies: text: Thank you for the careful writing. As Feynman would have said, good! --Ancheta Wis 12:32, 12 February 2006 (UTC)
thread_title:  My changes:  http://en.wikipedia.org/w/index.php?title=Quantum_mechanics&diff=39241812&oldid=39099331 

message: How about:
Once upon a time there was a particle of yellow light.  We call her Goldielocks, though light particles can't really have names.  She wandered until she came to an atom that had three bare electrons.  One electron was stuck too hard in the atom.  One was too loose.  The third was just right, so he and Goldielocks became a photoelectron.  ?  David R. Ingham 06:20, 20 February 2006 (UTC)
thread_title:  Children's book 

message: * JA: Re:
Quantum mechanics; 03:48 ... David R. Ingham (Talk) (→Description of the theory - I think this is a further improvement, but I don't think we are done. This is a good paragraph technically, but is it simple enough for the introducton?)
* JA: I dunno, it would depend on the charge of the introducton.  Jon Awbrey 04:00, 9 March 2006 (UTC)
thread_title:  Introducton 

message: I couldn't find anything on the quantum mechanics pages on the relation between quantum mechanics and free will. I think it's an interesting philosophical discussion, but unfortunately I know next to nothing about it. Anyone who does?
:You might try Max Jammer's book, which is listed in . See also the :Category:Quantum mechanics for the current articles on the topic. Warning: the topic is currently considered one of the imponderables. We do not seem to know enough yet. That is one reason you may not have found too much. Have you investigated the free will article, as a start? --Ancheta Wis 19:05, 7 May 2006 (UTC)
thread_title:  Quantum mechanics and free will discussion - missing