Timeline for A novice question on Quantum Mechanics
Current License: CC BY-SA 3.0
18 events
| when toggle format | what | by | license | comment | |
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| Aug 8, 2013 at 2:19 | comment | added | Andreas Blass | @ToddTrimble I agree with you about the lack of mathematical clarity, but I feel that this lack of clarity makes the physics difficult. More precisely: There are large parts of physics that I can understand, at least qualitatively, in an intutive way without going into a lot of mathematical details. But quantum mechanics is not such a part. It has enough counterintuitive aspects that the only way I can understand it is via the mathematics. So, to the extent that the mathematics is unclear, I find quantum mechanics difficult to understand. | |
| Aug 8, 2013 at 0:54 | comment | added | Todd Trimble | I don't think it's the physics that is so difficult as it is the lack of mathematical clarity with which some of the physical ideas are expressed. | |
| Dec 25, 2012 at 8:24 | answer | added | Vectornaut | timeline score: 4 | |
| Dec 25, 2012 at 3:05 | comment | added | Chris Gerig | @Litt: I originally voted to close as soon as the question was posted, because I saw it as a small misunderstanding of basic linear algebra and QM, which seemed outside of the scope of this forum. But I was not aware that other people did not view this as a trivial matter, and have gone well beyond giving an easy response (i.e. these were more informative than I would expect). Unfortunately, MO does not have a way for someone to unclose their own close-vote (this should be fixed!). | |
| Dec 24, 2012 at 23:12 | comment | added | Daniel Litt | I urge the people voting to close this question not to do so--it seems like a very reasonable question on a difficult subject for someone not familiar with physics (and there are many research mathematicians not familiar with physics). | |
| Dec 24, 2012 at 22:32 | answer | added | Bad English | timeline score: 1 | |
| Dec 24, 2012 at 21:36 | comment | added | Joël | @Michael: you're perfectly right. Superposition is not a well-defined operation on quantum states. In other words, superposition does not make sense physically. | |
| Dec 24, 2012 at 20:57 | answer | added | Igor Khavkine | timeline score: 5 | |
| Dec 24, 2012 at 15:28 | comment | added | Andreas Blass | To emphasize (perhaps excessively) a point from Robert Israel's answer: Despite the common phrase "superposition of states", one does not really superpose states; one superposes vectors that represent states. One can think of states as equivalence classes of vectors (vectors being equivalent iff they differ by a scalar factor), but superposition operations (with specified coefficients) are not well-defined on the equivalence classes. | |
| Dec 24, 2012 at 15:20 | comment | added | Michael Bächtold | After reading the answers is it correct to say that there is no well defined operation which takes two states and outputs the superposition of them? | |
| Dec 24, 2012 at 11:13 | answer | added | Konrad Waldorf | timeline score: 16 | |
| Dec 24, 2012 at 10:44 | answer | added | Chris Gerig | timeline score: 3 | |
| Dec 24, 2012 at 9:21 | answer | added | Federico Poloni | timeline score: 4 | |
| Dec 24, 2012 at 7:12 | answer | added | Leonard | timeline score: 8 | |
| Dec 24, 2012 at 6:31 | comment | added | Sam Hopkins | Note that defining quantum states as equivalence classes of unit vectors that differ only by a global phase will also lead to problems with composite states and tensor products (where the phase difference between two tensor factors now suddenly matters.) | |
| Dec 24, 2012 at 6:04 | answer | added | Robert Israel | timeline score: 5 | |
| Dec 24, 2012 at 5:54 | comment | added | Steve Huntsman | en.wikipedia.org/wiki/Bloch_sphere | |
| Dec 24, 2012 at 5:08 | history | asked | Ryan | CC BY-SA 3.0 |