<?xml version="1.0"?>
<feed xmlns="http://www.w3.org/2005/Atom" xml:lang="en">
		<id>https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&amp;feedformat=atom&amp;user=80.229.249.36</id>
		<title>explain xkcd - User contributions [en]</title>
		<link rel="self" type="application/atom+xml" href="https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&amp;feedformat=atom&amp;user=80.229.249.36"/>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php/Special:Contributions/80.229.249.36"/>
		<updated>2026-06-27T18:01:21Z</updated>
		<subtitle>User contributions</subtitle>
		<generator>MediaWiki 1.30.0</generator>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Talk:3264:_720_Ollie&amp;diff=415285</id>
		<title>Talk:3264: 720 Ollie</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Talk:3264:_720_Ollie&amp;diff=415285"/>
				<updated>2026-06-27T13:05:00Z</updated>
		
		<summary type="html">&lt;p&gt;80.229.249.36: a macroscopic spin 1/2 system&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;&amp;lt;!-- Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom. --&amp;gt;&lt;br /&gt;
Never really understood skateboards myself [[Special:Contributions/216.25.182.141|216.25.182.141]] 03:00, 27 June 2026 (UTC)&lt;br /&gt;
:That's okay.  I never really understood human-scale spin-½ fermions.  [[Special:Contributions/2603:8081:9700:1224:0:0:0:2|2603:8081:9700:1224:0:0:0:2]] 03:18, 27 June 2026 (UTC)&lt;br /&gt;
Early footage of Tony exploring rotational symmetries: The Loop (2001) https://www.youtube.com/watch?v=PLC1V22Y7iY&lt;br /&gt;
Note that he needs to go around the loop twice before he can return to his original orientation and land the trick. [[Special:Contributions/86.23.176.63|86.23.176.63]] 03:39, 27 June 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
Riding &amp;quot;regular&amp;quot; vs &amp;quot;goofy&amp;quot; just means which foot is placed at the front, it has no real effect on what you can or can't do so you could describe it as a &amp;quot;symmetry&amp;quot; similar to symmetries in physics. Discovering a way to break that symmetry would, in theory, be an important discovery to people who cared about theoretical skateboarding. [[User:Undergroundmonorail|Undergroundmonorail]] ([[User talk:Undergroundmonorail|talk]]) 04:37, 27 June 2026 (UTC)&lt;br /&gt;
:I think the parallel is to the way that total 'spins' and other things are (or perhaps notably aren't) conserved across various feynman diagrams, and your footedness is a state of the system (you can change it, mid-trick, but then the switch becomes ''part'' of thst trick) like the charge is a part of any given interaction/combination/decomposition of particles. Obviously any southpaw (south''pad''?) skater may bias towards or away from certain normal/goofy stances that a standard contrmporary may bias oppositely to, but it sounds like the comic is suggesting something even more fundemental about differences in that (e.g.) left-turns in both modes (by all types of rider) are statistically tighter than right-turns by exactly flip-matched individuals. Or something like that. (Taking this complete hypothetical further, the studies regarding this need to be done in both north and south hemispheres, to rule out it simply being a skateboard-detected consequence of the Coriolis force! While a single X Games is not enough to check this, I believe subsequent events have been held in opposing hemispheres. ;p )&lt;br /&gt;
:Of course it's analogy-stretching (both the comic and myself), but this is xkcd. Stretching of analogies (both within the range of Hooke's law and even beyond the elastic limit, whether under tension, compression, torsion, etc) is what both Randall and ourselves do. ;) [[Special:Contributions/82.132.238.177|82.132.238.177]] 11:10, 27 June 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
&amp;quot;Tony Hawk is not a subatomic particle {{citation needed}}&amp;quot; XD [[Special:Contributions/2401:4900:ADC9:33ED:3028:A249:ED24:CD91|2401:4900:ADC9:33ED:3028:A249:ED24:CD91]] 07:00, 27 June 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
Nevertheless Tony Hawk is awesome and can do anything a subatomic particle can do. Alas, the description (why a fermion differs from a boson) is not dumb enough for me to understand, tho. [[User:Dúthomhas|Dúthomhas]] ([[User talk:Dúthomhas|talk]]) 07:46, 27 June 2026 (UTC)&lt;br /&gt;
:I think we need to properly investigate the abilities of the {{w|Tony Hawks|supersymmetric version}} of Tony Hawk. We do know that he's capable of walking long distances with fridges, can play tennis, etc, but we're still some way from a direct comparison under a Grand Unified Theory. [[Special:Contributions/82.132.238.177|82.132.238.177]] 11:52, 27 June 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
I must admit, when I started reading the comic I was initially thinkingnit was going to be something to do with the tendency of objects spun around a minor axis to also flip (unbidden) around their major axis. Remote controls, table-tennis bats, anything where a 360° flip is obviously happening but lands back in your hand 180° rotated, longitudinally (buttons now faced down, red/black paddle surfaces inverted, etc), regardless(/specificallly) of how carefully you try to do a perfect one-axis spin of tbis manner. — So, now I'm wondering, is ''that'' the underlying reason for the quantum-mechanical 'half-spins'? Whereby an unrelated (and not understood/hidden-variable) long-axis spin exhibits an apparent half-spin as a precessionary artefact? Or it's 'just' a more standard topological rotational symmetry of ½ made 'real'. (Of ''course'' I know that 'spin' isn't anything much like classical physics spinning, like quarks don't have colours, just [[2734: Electron Color|everything else]].) [[Special:Contributions/82.132.238.177|82.132.238.177]] 11:52, 27 June 2026 (UTC)&lt;br /&gt;
&lt;br /&gt;
Maybe its been mentioned but a real world example of a macroscopic spin 1/2 system is where the object is tethered to a fixed point and the tether can bend but not twist. Simple example is holding a coffee cup in your hand (I can't actually do this, my arm isn't flexible enough) you can rotate the cup 360 degrees over your arm but your arm gets kind of twisted, if you then rotate the cup under your arm your arm untwists and you get back to the original position. I'm sure I saw someone demonstrate this in a lecture and I thought I could do it but can't seem to make it work. &lt;br /&gt;
&lt;br /&gt;
Anyway my point is you get a macroscopic system where the cup needs to rotate 720 degrees to return the system to its starting point.&lt;br /&gt;
&lt;br /&gt;
Also when using quaternions to handle rotation in 3D game design they seem to define a spin 1/2 system but you just have to deal with it, its just numbers&lt;br /&gt;
&lt;br /&gt;
[[Special:Contributions/80.229.249.36|80.229.249.36]] 13:05, 27 June 2026 (UTC)&lt;/div&gt;</summary>
		<author><name>80.229.249.36</name></author>	</entry>

	</feed>