https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&feedformat=atom&user=Burnside 2026-04-15T13:58:14Z User contributions MediaWiki 1.30.0 https://www.explainxkcd.com/wiki/index.php?title=3027:_Exclusion_Principle&diff=360054 2024-12-21T18:14:08Z

<p>Burnside: Typo and formatting wiki link</p> <hr /> <div>{{comic<br /> | number = 3027<br /> | date = December 20, 2024<br /> | title = Exclusion Principle<br /> | image = exclusion_principle_2x.png<br /> | imagesize = 264x336px<br /> | noexpand = true<br /> | titletext = Fermions are weird about each other in a standoffish way. Integer-spin particles are weird about each other in a 'stand uncomfortably close while talking' kind of way.<br /> }}<br /> <br /> ==Explanation==<br /> {{incomplete|Created by a SOCIALLY ANXIOUS ELECTRON - Someone who knows more about physics should explain this. Also, the title text needs explanation. Do NOT delete this tag too soon.}}<br /> This comic is about the four fundamental forces of physics: gravity, electromagnetism, the strong force, and the weak force. In typical xkcd fashion, [[Randall]] also adds a joke entry: &quot;Electrons are weird about each other&quot;. This is a description of how two or more electrons cannot share the exact same &quot;spot&quot;. The name of this property is Pauli Exclusion Principle, and Randall has made [[658: Orbitals|xkcd 658]] about it. This is not directly a force: electrons on neighbouring spots do not &quot;feel&quot; each others presence and it's not possible to push one electron so hard that it goes into a spot that an electron already has - properties normal forces have. However, the combination of Pauli exclusion with the actual force of electromagnetism makes electrons behave as if there was a force additional to the electromagnetic one, the {{w|exchange interaction}}.<br /> This is much harder to understand than simple forces, so Randall jokes that Physicists had given up, resolving to make it a force instead.<br /> Randall makes it sounds like Physicists behaved like politicians, changing the laws (of nature) so that they're easier for them. In reality, humanity does not know a way to change the workings of nature, and scientist merely try to figure out and describe how nature works.<br /> <br /> The title text expands from electrons to ''fermions'', the class of particles electron belong to, and ''bosons'', the other class of particles.<br /> All fermions share the property of electrons of not being able to share the same spot. Bosons on the other hand, can do that - you can put two or really any amount of Bosons into one spot. Randall refers to this as &quot;stand uncomfortably close while talking&quot;. This gives rise to quantum effects like {{w|superconductivity}}.<br /> <br /> Interactions between electrons are different from how human interactions can depend upon the concept of 'personal space', and they are therefore ‘weird’, which also explains the title text. <br /> <br /> ==Transcript==<br /> :[Inside the panel, there is an underlined header and a numbered list, with the fifth and last item in red:]<br /> :&lt;u&gt;Fundamental Forces&lt;/u&gt;<br /> :1. Gravity &lt;br&gt;<br /> :2. Electromagnetism &lt;br&gt;<br /> :3. The Weak Interaction &lt;br&gt;<br /> :4. The Strong Interaction &lt;br&gt;<br /> :&lt;span style=&quot;color:red&quot;&gt;''5. Electrons are weird about each other''&lt;/span&gt;<br /> <br /> :[Caption below the panel:]<br /> :Big news: Physicists have finally given up trying to explain about the &quot;exchange interaction&quot; and agreed to just make the exclusion principle a force. <br /> <br /> {{comic discussion}}<br /> <br /> [[Category:Comics with color]]<br /> [[Category:Comics with red annotations]]<br /> [[Category:Physics]]</div>

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