<?xml version="1.0" encoding="UTF-8" standalone="yes"?><oembed><version><![CDATA[1.0]]></version><provider_name><![CDATA[Carcinisation]]></provider_name><provider_url><![CDATA[http://carcinisation.com]]></provider_url><author_name><![CDATA[strevdrrev]]></author_name><author_url><![CDATA[https://carcinisation.com/author/strevdrrev/]]></author_url><title><![CDATA[Local and Global and the Terrible Telescope, Part&nbsp;1]]></title><type><![CDATA[link]]></type><html><![CDATA[<p>In the comment thread for <a title="How to Tell Whether You Are Being Oppressed" href="http://carcinisation.com/2014/07/27/how-to-tell-whether-you-are-being-oppressed/">my previous post</a>, I remarked that</p>
<blockquote><p>I don’t know of a good theory that bridges the chasm between individual justice (where I think free association is an important fundamental right) and global justice (universal behaviors like [<em>modes of systemic oppression</em>]). I don’t pretend to have one.</p></blockquote>
<p>What I&#8217;d like to do in this series is try to convince you that you probably don&#8217;t have one either.</p>
<ul>
<li style="text-align:center;"><em>Local and Global <big>•</big> William Lane Craig is Terrible <big>•</big> Kant is Also Terrible </em></li>
<li style="text-align:center;"><em>the Repugnant Conclusion is Neither <big>•</big> Telescoping Considered Harmful</em></li>
<li style="text-align:center;"><em>You Are Not God, You&#8217;re Not Even President of the Galaxy</em></li>
<li style="text-align:center;"><em> The Can&#8217;tegorical Imperative <big>•</big> Further Reading</em></li>
</ul>
<p><strong>1. Local and Global</strong></p>
<p>One hard lesson every student of advanced mathematics learns is that a construction that seems easy and obvious <strong>locally</strong>&#8211;for instance, in a small region of a space&#8211;can be very difficult, or outright impossible, to make meaningful <strong>globally</strong>&#8211;eg, over the whole space.</p>
<p>For example, think about the direction &#8216;North&#8217;.  Which way is north? Wherever you happen to be reading this, you probably know already; if you don&#8217;t, your phone can probably tell you. &#8216;North&#8217; is an easy <strong>local</strong> concept&#8211;we can all check which way north lies. We can find &#8216;north&#8217;, no matter where we go. Right?</p>
<p>Wrong.</p>
<p><!--more--></p>
<div data-shortcode="caption" id="attachment_167" style="width: 1034px" class="wp-caption aligncenter"><a href="https://carcinisation.files.wordpress.com/2014/08/northpole30.jpg"><img data-attachment-id="167" data-permalink="https://carcinisation.com/2014/08/02/local-and-global-and-the-terrible-telescope-part-1/northpole30/" data-orig-file="https://carcinisation.files.wordpress.com/2014/08/northpole30.jpg" data-orig-size="1024,768" data-comments-opened="1" data-image-meta="{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}" data-image-title="NorthPole30" data-image-description="" data-medium-file="https://carcinisation.files.wordpress.com/2014/08/northpole30.jpg?w=300" data-large-file="https://carcinisation.files.wordpress.com/2014/08/northpole30.jpg?w=1024" class="wp-image-167 size-large" src="https://carcinisation.files.wordpress.com/2014/08/northpole30.jpg?w=1024&#038;h=767" alt="NorthPole30" srcset="https://carcinisation.files.wordpress.com/2014/08/northpole30.jpg 1024w, https://carcinisation.files.wordpress.com/2014/08/northpole30.jpg?w=1023&amp;h=767 1023w, https://carcinisation.files.wordpress.com/2014/08/northpole30.jpg?w=150&amp;h=113 150w, https://carcinisation.files.wordpress.com/2014/08/northpole30.jpg?w=300&amp;h=225 300w, https://carcinisation.files.wordpress.com/2014/08/northpole30.jpg?w=768&amp;h=576 768w" sizes="(max-width: 1024px) 100vw, 1024px"   /></a><p class="wp-caption-text">It&#8217;s Grim Up North</p></div>
<p>There are two points on the surface of the Earth where you can&#8217;t meaningfully define &#8216;north&#8217;: the poles. At the North Pole, you can&#8217;t go any further north: <em>every direction</em> is south! At the south pole, <em>every</em> direction is north, so &#8216;north&#8217; isn&#8217;t unique, and so isn&#8217;t well-defined.</p>
<div style="width: 339px" class="wp-caption aligncenter"><img src="https://upload.wikimedia.org/wikipedia/commons/archive/f/fe/20090822201540!Arctic_Ocean.png" alt="" width="329" height="330" /><p class="wp-caption-text">Where do we go from here?</p></div>
<p>(East and west are also problematic.)</p>
<div style="width: 611px" class="wp-caption aligncenter"><img src="https://skullsinthestars.files.wordpress.com/2012/09/rightleftcomb.jpg?w=601&#038;h=315" alt="" width="601" height="315" /><p class="wp-caption-text">East is East and West is West and Never the Twain Shall Be Globally Well-Defined</p></div>
<p>In fact, you can prove mathematically that there is <em>no possible way</em> to extend &#8216;north&#8217; in a consistent way to every point on the globe. This fact is called the <a href="https://en.wikipedia.org/wiki/Hairy_ball_theorem">Hairy Ball Theorem</a>. (Yeah, seriously, that&#8217;s what it&#8217;s called.)</p>
<div style="width: 410px" class="wp-caption aligncenter"><img src="https://upload.wikimedia.org/wikipedia/en/5/50/ST_TroubleWithTribbles.jpg" alt="" width="400" height="294" /><p class="wp-caption-text">You can&#8217;t comb a tribble flat, Jim!</p></div>
<p>The local-global problem is ubiquitous in mathematics. Ideas that make sense up close turn out, again and again, to be difficult or impossible to extend everywhere.  There are <a href="https://en.wikipedia.org/wiki/Obstruction_theory">whole areas of mathematics</a> that focus on the question of whether you can extend an idea from a part to the whole.</p>
<p>What&#8217;s any of this got to do with moral philosophy? I hope to persuade you: a whole lot.</p>
<p><strong>Next</strong>: Geometric Theology.</p>
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