{"id":1847,"date":"2018-02-14T15:18:24","date_gmt":"2018-02-14T23:18:24","guid":{"rendered":"http:\/\/antoine.wojdyla.fr\/blog\/?p=1847"},"modified":"2018-02-04T16:20:58","modified_gmt":"2018-02-05T00:20:58","slug":"self-reference","status":"publish","type":"post","link":"http:\/\/antoine.wojdyla.fr\/blog\/2018\/02\/14\/self-reference\/","title":{"rendered":"Self-reference"},"content":{"rendered":"<p>Self-reference is cornerstone in Hofstadter&#8217;s Godel-Escher-Bach, a <a href=\"http:\/\/antoine.wojdyla.fr\/blog\/2018\/01\/02\/books-i-loved\/\">must read book<\/a> for anyone interested in logic (and we shall rely logic in these days to stay sane.)<\/p>Here&#8217;s a bunch of examples of self-reference that I found interesting, curated just for you!<\/p><strong>Barber&#8217;s paradox<\/strong>:<\/p>\n<blockquote><p><span class=\"_Tgc _s8w\">The barber is the &#8220;one who shaves all those, and those <b>only<\/b>, who do not shave themselves.&#8221; The question is, does the barber shave himself? <\/span><\/p><\/blockquote><p><strong>Self-referential figure<\/strong> (via <a href=\"https:\/\/xkcd.com\/688\/\" onclick=\"_gaq.push(['_trackEvent', 'outbound-article', 'https:\/\/xkcd.com\/688\/', 'xkcd']);\" >xkcd<\/a>):<\/p><a href=\"http:\/\/antoine.wojdyla.fr\/blog\/wp-content\/uploads\/xkcd_self_description.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-1848 aligncenter\" src=\"http:\/\/antoine.wojdyla.fr\/blog\/wp-content\/uploads\/xkcd_self_description.png\" alt=\"\" width=\"740\" height=\"180\" srcset=\"http:\/\/antoine.wojdyla.fr\/blog\/wp-content\/uploads\/xkcd_self_description.png 740w, http:\/\/antoine.wojdyla.fr\/blog\/wp-content\/uploads\/xkcd_self_description-300x73.png 300w\" sizes=\"auto, (max-width: 740px) 100vw, 740px\" \/><\/a><\/p><strong>Tupper&#8217;s formula<\/strong> that prints itself on a screen (via <a href=\"https:\/\/twitter.com\/fermatslibrary\/status\/960154478224793600\" onclick=\"_gaq.push(['_trackEvent', 'outbound-article', 'https:\/\/twitter.com\/fermatslibrary\/status\/960154478224793600', 'Brett Richardson']);\" >Brett Richardson<\/a>)<a href=\"http:\/\/antoine.wojdyla.fr\/blog\/wp-content\/uploads\/Tupper-self-referential.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-1849 size-full aligncenter\" src=\"http:\/\/antoine.wojdyla.fr\/blog\/wp-content\/uploads\/Tupper-self-referential-e1517785536277.jpg\" alt=\"\" width=\"637\" height=\"236\" srcset=\"http:\/\/antoine.wojdyla.fr\/blog\/wp-content\/uploads\/Tupper-self-referential-e1517785536277.jpg 637w, http:\/\/antoine.wojdyla.fr\/blog\/wp-content\/uploads\/Tupper-self-referential-e1517785536277-300x111.jpg 300w\" sizes=\"auto, (max-width: 637px) 100vw, 637px\" \/><\/a><!--more--><\/p>A strange loop:<\/p><iframe loading=\"lazy\" src=\"https:\/\/www.youtube.com\/embed\/Y-gqMTt3IUg\" width=\"560\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>Venturing into <strong>coastal fractals<\/strong>:<\/p><a href=\"http:\/\/antoine.wojdyla.fr\/blog\/wp-content\/uploads\/coast.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-1850 aligncenter\" src=\"http:\/\/antoine.wojdyla.fr\/blog\/wp-content\/uploads\/coast.gif\" alt=\"\" width=\"280\" height=\"200\" \/><\/a>Slightly off topic:<a href=\"http:\/\/antoine.wojdyla.fr\/blog\/wp-content\/uploads\/444.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-1851 aligncenter\" src=\"http:\/\/antoine.wojdyla.fr\/blog\/wp-content\/uploads\/444.jpg\" alt=\"\" width=\"399\" height=\"600\" srcset=\"http:\/\/antoine.wojdyla.fr\/blog\/wp-content\/uploads\/444.jpg 399w, http:\/\/antoine.wojdyla.fr\/blog\/wp-content\/uploads\/444-200x300.jpg 200w\" sizes=\"auto, (max-width: 399px) 100vw, 399px\" \/><\/a>I&#8217;ll add more as I go!<\/p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Self-reference is cornerstone in Hofstadter&#8217;s Godel-Escher-Bach, a must read book for anyone interested in logic (and we shall rely logic in these days to stay sane.)Here&#8217;s a bunch of examples of self-reference that I found interesting, curated just for you!Barber&#8217;s paradox: The barber is the &#8220;one who shaves all those, and those only, who do [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,11,6,14,16,10],"tags":[],"class_list":["post-1847","post","type-post","status-publish","format-standard","hentry","category-art-science","category-english","category-mood","category-projects","category-resources","category-skepticality"],"_links":{"self":[{"href":"http:\/\/antoine.wojdyla.fr\/blog\/wp-json\/wp\/v2\/posts\/1847","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/antoine.wojdyla.fr\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/antoine.wojdyla.fr\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/antoine.wojdyla.fr\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/antoine.wojdyla.fr\/blog\/wp-json\/wp\/v2\/comments?post=1847"}],"version-history":[{"count":1,"href":"http:\/\/antoine.wojdyla.fr\/blog\/wp-json\/wp\/v2\/posts\/1847\/revisions"}],"predecessor-version":[{"id":1852,"href":"http:\/\/antoine.wojdyla.fr\/blog\/wp-json\/wp\/v2\/posts\/1847\/revisions\/1852"}],"wp:attachment":[{"href":"http:\/\/antoine.wojdyla.fr\/blog\/wp-json\/wp\/v2\/media?parent=1847"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/antoine.wojdyla.fr\/blog\/wp-json\/wp\/v2\/categories?post=1847"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/antoine.wojdyla.fr\/blog\/wp-json\/wp\/v2\/tags?post=1847"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}