[HN Gopher] The Mystery of Spin ___________________________________________________________________ The Mystery of Spin Author : cratermoon Score : 11 points Date : 2022-11-26 19:36 UTC (1 days ago) (HTM) web link (www.math.columbia.edu) (TXT) w3m dump (www.math.columbia.edu) | BMc2020 wrote: | _There's no mystery here about what the spin angular momentum is: | all one has done is used the proper definition of the angular | momentum as infinitesimal generator of rotations and taken into | account the fact that in this case rotations also act on the | vector values, not just on space. One can easily generalize this | to tensor-valued wave-functions by using the matrices for | rotations on them, getting higher integral values of the spin._ | | Well, Duh. | the__alchemist wrote: | I'd prefer to see less use of "all one has done", "just", | "easily", and "trivial". | wnoise wrote: | I know you're being sarcastic, but this is actually just table- | stakes for any sort of research in fundamental physics. This is | quite analogous to linear momentum being the generator of | translation, yet having mysterious components in E&M that | aren't a particle moving, but charge interacting with the | somewhat inscrutable "vector potential". | [deleted] | quickthrower2 wrote: | If I understand the point of the article it is: | | a. Not worth understanding the mysteries. | | b. Electrons have spin classically, so no need to talk about | Quantum Field Theory | | And then posts some equations about spin. | | I presume (a) is because we would get into "God" territory and | (b) is to make the discussion simpler. | tinym wrote: | No, the mysteries that "are deep, hard to understand, and not | worth the effort" are why Scientific American is publishing | this junk article. My lay theory is that SA hasn't been worth | reading in decades and basically nobody can write well about | quantum mechanics for a casual audience.. | mhh__ wrote: | Tomonagas book "the story of spin" is a banger. Really gentle at | times but very detailed and insightful at other times ___________________________________________________________________ (page generated 2022-11-27 23:00 UTC)