Difference between revisions of "Talk:2882: Net Rotations"

Explain xkcd: It's 'cause you're dumb.
Jump to: navigation, search
(actual torsion problem)
Line 21: Line 21:
  
 
This comic makes sense in 2D because the space of rotations has fundamental group ℤ, but in 3D wouldn't you have at most ℤ/2ℤ corrections to make, since SU(2) double-covers SO(3)? cf. https://en.wikipedia.org/wiki/Plate_trick [[User:Ncf|Ncf]] ([[User talk:Ncf|talk]]) 09:27, 18 January 2024 (UTC)
 
This comic makes sense in 2D because the space of rotations has fundamental group ℤ, but in 3D wouldn't you have at most ℤ/2ℤ corrections to make, since SU(2) double-covers SO(3)? cf. https://en.wikipedia.org/wiki/Plate_trick [[User:Ncf|Ncf]] ([[User talk:Ncf|talk]]) 09:27, 18 January 2024 (UTC)
 +
 +
Is it worth mentioning the real medical conditions of torsion, e. . a torsion fracture (https://en.wikipedia.org/wiki/Torsion_fracture)? [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 12:43, 18 January 2024 (UTC)

Revision as of 12:43, 18 January 2024

Wait, so I'm not the only one who thinks about this? 172.71.167.177 23:28, 17 January 2024 (UTC)

Second! Still, I'm surprised that there are no edits yet. 172.70.210.160 23:58, 17 January 2024 (UTC)

This sounds like the premise of the 1966 sci-fi story The Revolving Boy by Gertrude Friedberg. I recall reading it sometime in the 1960s or ’70s. I wonder whether Randall has read the book too — https://solarbridge.wordpress.com/2011/05/19/the-revolving-boy-gertrude-friedberg/ I'm drawing a blank. 162.158.158.68 01:05, 18 January 2024 (UTC)

I feel like the "worldline torsion" line needs to be explained moreso than the OCD thing, since "worldline" is a word people might not know and it's the crux of the joke. 162.158.62.50 02:47, 18 January 2024 (UTC)

A worldline is a relativistic concept, the track of a particle (or anything, by extension) through 4D spacetime. Randall is imagining it as a physical object (not a mathematical abstraction) and thus whenever the actual object rotates, its worldline is twisted. Presumably these physical worldlines would build up torsional potential energy as they twisted, and could eventually be damaged if too many twists/year were present.Nitpicking (talk) 02:57, 18 January 2024 (UTC)
Yeah - something like that needs to go in the explanation.172.70.85.47 09:44, 18 January 2024 (UTC)

I would love to know what my net rotations is. Not enough to actually keep track, mind you. 172.70.178.126 02:53, 18 January 2024 (UTC)

I had a season pass to an amusement park a few years ago, and the time I spent on the Scrambler would probably make mine quite difficult to calculate, even if I knew how many times I rode it. 172.69.247.57 04:41, 18 January 2024 (UTC)
Probably depends a lot on whether you suffer from Zoolander's Syndrome. 172.70.91.62 09:48, 18 January 2024 (UTC)

isn't this a refernce to spacetime torsion and the einstien-cartan theory? https://en.wikipedia.org/wiki/Einstein%E2%80%93Cartan_theory

When I used to do plasma donations (they draw blood, centrifuge it, extract the plasma/platelet fraction and return the red and white cells) I would, when telling someone about it, jokingly say that the only side effect was, then I would jump and spin. RIIW - Ponder it (talk) 08:17, 18 January 2024 (UTC)

This comic makes sense in 2D because the space of rotations has fundamental group ℤ, but in 3D wouldn't you have at most ℤ/2ℤ corrections to make, since SU(2) double-covers SO(3)? cf. https://en.wikipedia.org/wiki/Plate_trick Ncf (talk) 09:27, 18 January 2024 (UTC)

Is it worth mentioning the real medical conditions of torsion, e. . a torsion fracture (https://en.wikipedia.org/wiki/Torsion_fracture)? Nitpicking (talk) 12:43, 18 January 2024 (UTC)