{"id":108,"date":"2016-03-14T20:36:03","date_gmt":"2016-03-15T00:36:03","guid":{"rendered":"http:\/\/blog.law.cornell.edu\/tech\/?p=108"},"modified":"2016-03-15T08:30:07","modified_gmt":"2016-03-15T12:30:07","slug":"american-pi","status":"publish","type":"post","link":"https:\/\/blog.law.cornell.edu\/tech\/2016\/03\/14\/american-pi\/","title":{"rendered":"American Pi"},"content":{"rendered":"<p>In 2009, the US House of Representatives agreed to a <a href=\"https:\/\/www.govtrack.us\/congress\/bills\/111\/hres224\">resolution designating March 14 as &#8220;Pi Day&#8221;<\/a>.<\/p>\n<p>So I thought I&#8217;d see whether I could rustle up a nice example of pi in the Code of Federal Regulations.\u00a0I did manage to find <a href=\"https:\/\/www.law.cornell.edu\/cfr\/text\/40\/98.233\">the \u03c0 I was looking for<\/a>, but it turns out that pi also gives us some examples of why we need to disambiguate.<\/p>\n<p>In the process I also found:<\/p>\n<ul>\n<li><strong>Pi Tape<\/strong>\u00ae (who knew?) in the <a href=\"https:\/\/www.law.cornell.edu\/cfr\/text\/40\/1066.225\">dynamometer verification and calibration procedures<\/a> in vehicle emissions tests;<\/li>\n<li>The specific heat of water: &#8220;C<sub><strong>pi<\/strong><\/sub> = the specific heat of the water of the ith draw&#8221; in the\u00a0<a href=\"https:\/\/www.law.cornell.edu\/cfr\/text\/10\/part-430\/subpart-B\/appendix-E\">test methods for measuring the energy consumption of water heaters<\/a>;<\/li>\n<li><a href=\"https:\/\/www.law.cornell.edu\/cfr\/text\/32\/767.6\">Required credentials<\/a> for a \u00a0<strong>principal investigator<\/strong>\u00a0applying for a permit to study a wreck under the control of the Navy;<\/li>\n<li>The <strong>post-inoculation<\/strong>\u00a0<a href=\"https:\/\/www.law.cornell.edu\/cfr\/text\/9\/113.208\">requirements of the chicken embryo test<\/a> for avian encephalomyelitis vaccine inactivation;<\/li>\n<li><strong>Packaging instructions<\/strong>\u00a0<a href=\"https:\/\/www.law.cornell.edu\/cfr\/text\/49\/173.62\">requirements for transporting explosives<\/a>;<\/li>\n<li><a href=\"https:\/\/www.law.cornell.edu\/cfr\/text\/26\/1.904-6\">Tax treatment<\/a> of <strong>passive income<\/strong>;<\/li>\n<li>A\u00a0<a href=\"https:\/\/www.law.cornell.edu\/cfr\/text\/20\/71.7\">mailing address<\/a> in the\u00a0<strong>Philippine Islands<\/strong>.<\/li>\n<\/ul>\n<p>So the story of &#8220;pi&#8221; in the CFR is a story of disambiguation. When we read (or our software parses) the original text of a particular regulation, it&#8217;s reasonably straightforward to tell which of the many &#8220;pi&#8221;s it&#8217;s discussing. We have capitalization, punctuation, formatting, and structural and contextual clues. Once the search engines work their case-folding,\u00a0acronym normalization, and other magic, we end up with an awful lot of &#8220;pi&#8221;s and very little context.<\/p>\n<p>Postscript. The real pi was a bit of a letdown: &#8220;P = pi (3.14)&#8221; &#8211; well, close enough.<\/p>\n<!-- AddThis Advanced Settings generic via filter on the_content --><!-- AddThis Share Buttons generic via filter on the_content -->","protected":false},"excerpt":{"rendered":"<p>In 2009, the US House of Representatives agreed to a resolution designating March 14 as &#8220;Pi Day&#8221;. So I thought I&#8217;d see whether I could rustle up a nice example of pi in the Code of Federal Regulations.\u00a0I did manage to find the \u03c0 I was looking for, but it turns out that pi also <a href='https:\/\/blog.law.cornell.edu\/tech\/2016\/03\/14\/american-pi\/'>[&#8230;]<\/a><!-- AddThis Advanced Settings generic via filter on get_the_excerpt --><!-- AddThis Share Buttons generic via filter on get_the_excerpt --><\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/blog.law.cornell.edu\/tech\/wp-json\/wp\/v2\/posts\/108"}],"collection":[{"href":"https:\/\/blog.law.cornell.edu\/tech\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.law.cornell.edu\/tech\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.law.cornell.edu\/tech\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.law.cornell.edu\/tech\/wp-json\/wp\/v2\/comments?post=108"}],"version-history":[{"count":3,"href":"https:\/\/blog.law.cornell.edu\/tech\/wp-json\/wp\/v2\/posts\/108\/revisions"}],"predecessor-version":[{"id":111,"href":"https:\/\/blog.law.cornell.edu\/tech\/wp-json\/wp\/v2\/posts\/108\/revisions\/111"}],"wp:attachment":[{"href":"https:\/\/blog.law.cornell.edu\/tech\/wp-json\/wp\/v2\/media?parent=108"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.law.cornell.edu\/tech\/wp-json\/wp\/v2\/categories?post=108"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.law.cornell.edu\/tech\/wp-json\/wp\/v2\/tags?post=108"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}