{"id":3031,"date":"2021-11-02T01:09:15","date_gmt":"2021-11-02T00:09:15","guid":{"rendered":"https:\/\/lecercleetlecarre.fr\/?p=3031"},"modified":"2025-01-20T19:33:17","modified_gmt":"2025-01-20T18:33:17","slug":"parce-que-vous-saviez-deja-que-tout-cercle-est-un-carre-qui-signore","status":"publish","type":"post","link":"https:\/\/lecercleetlecarre.fr\/index.php\/2021\/11\/02\/parce-que-vous-saviez-deja-que-tout-cercle-est-un-carre-qui-signore\/","title":{"rendered":"Parce que vous saviez d\u00e9j\u00e0 que tout Cercle est un Carr\u00e9 qui s&#8217;ignore&#8230;"},"content":{"rendered":"\n<p>Le nom de notre association, <em>Le Cercle et Le Carr\u00e9<\/em>, n&#8217;a plus aucun secret pour vous depuis longtemps. Mais on ne vous avait pas tout dit : ce qui est vrai en deux dimensions, l&#8217;est aussi en trois dimensions&#8230; topologiques. Pla\u00eet-il ?<\/p>\n\n\n\n<p>En clair, &#8221; <em>Toute 3-vari\u00e9t\u00e9 compacte, sans bord, et simplement connexe, est hom\u00e9omorphe \u00e0 la 3-sph\u00e8re<\/em> &#8220;. \u00c9l\u00e9mentaire, mon cher Poincar\u00e9, ou&#8230; &#8221; point carr\u00e9 &#8220;, comme dirait Cic\u00e9ron. Mais ne nous \u00e9garons pas plus et \u00e9coutons plut\u00f4t cette explication (une \u00e9mission de 9&#8217;53 min d&#8217;Arte, avec beaucoup d&#8217;images anim\u00e9es), qui devrait pouvoir satisfaire le commun des mortels (enfin, moi, tout au moins) :<\/p>\n\n\n\n<p><\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"La conjecture de Poincar\u00e9  | Voyages au pays des maths | ARTE\" width=\"676\" height=\"380\" src=\"https:\/\/www.youtube.com\/embed\/czY7sp5c_Xs?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<p>Si vous comprenez qu&#8217;une sph\u00e8re plate n&#8217;est au fond qu&#8217;un carr\u00e9 allong\u00e9, vous aurez 42 bonnes raisons de vous r\u00e9jouir et vous saurez d\u00e9sormais tout ce qu&#8217;il faut pour \u00e9chapper au lasso topologique&#8230; et aux donuts ! En plus d&#8217;avoir cr\u00e9\u00e9 de nouveaux chemins neuronaux dans votre cerveau, vous pourrez approfondir vos pratiques dans des dimensions jusqu&#8217;\u00e0 pr\u00e9sent inexplor\u00e9es ! Si \u00e7a, \u00e7a n&#8217;est pas une bonne nouvelle \ud83d\ude00<\/p>\n\n\n\n<p><\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"380\" height=\"380\" src=\"https:\/\/lecercleetlecarre.fr\/wp-content\/uploads\/2021\/11\/la_quadrature_du_net.jpg\" alt=\"\" class=\"wp-image-3032\" srcset=\"https:\/\/lecercleetlecarre.fr\/wp-content\/uploads\/2021\/11\/la_quadrature_du_net.jpg 380w, https:\/\/lecercleetlecarre.fr\/wp-content\/uploads\/2021\/11\/la_quadrature_du_net-300x300.jpg 300w, https:\/\/lecercleetlecarre.fr\/wp-content\/uploads\/2021\/11\/la_quadrature_du_net-150x150.jpg 150w\" sizes=\"auto, (max-width: 380px) 100vw, 380px\" \/><\/figure>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Le nom de notre association, Le Cercle et Le Carr\u00e9, n&#8217;a plus aucun secret pour vous depuis longtemps. Mais on ne vous avait pas tout dit : ce qui est &hellip; <a href=\"https:\/\/lecercleetlecarre.fr\/index.php\/2021\/11\/02\/parce-que-vous-saviez-deja-que-tout-cercle-est-un-carre-qui-signore\/\" class=\"more-link\">Lire la suite de <span class=\"screen-reader-text\">Parce que vous saviez d\u00e9j\u00e0 que tout Cercle est un Carr\u00e9 qui s&#8217;ignore&#8230;<\/span><\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_s2mail":"yes","_EventAllDay":false,"_EventTimezone":"","_EventStartDate":"","_EventEndDate":"","_EventStartDateUTC":"","_EventEndDateUTC":"","_EventShowMap":false,"_EventShowMapLink":false,"_EventURL":"","_EventCost":"","_EventCostDescription":"","_EventCurrencySymbol":"","_EventCurrencyCode":"","_EventCurrencyPosition":"","_EventDateTimeSeparator":"","_EventTimeRangeSeparator":"","_EventOrganizerID":[],"_EventVenueID":[0],"_OrganizerEmail":"","_OrganizerPhone":"","_OrganizerWebsite":"","_VenueAddress":"","_VenueCity":"","_VenueCountry":"","_VenueProvince":"","_VenueState":"","_VenueZip":"","_VenuePhone":"","_VenueURL":"","_VenueStateProvince":"","_VenueLat":"","_VenueLng":"","_VenueShowMap":false,"_VenueShowMapLink":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-3031","post","type-post","status-publish","format-standard","hentry","category-non-classe"],"_links":{"self":[{"href":"https:\/\/lecercleetlecarre.fr\/index.php\/wp-json\/wp\/v2\/posts\/3031","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lecercleetlecarre.fr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lecercleetlecarre.fr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lecercleetlecarre.fr\/index.php\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/lecercleetlecarre.fr\/index.php\/wp-json\/wp\/v2\/comments?post=3031"}],"version-history":[{"count":6,"href":"https:\/\/lecercleetlecarre.fr\/index.php\/wp-json\/wp\/v2\/posts\/3031\/revisions"}],"predecessor-version":[{"id":4838,"href":"https:\/\/lecercleetlecarre.fr\/index.php\/wp-json\/wp\/v2\/posts\/3031\/revisions\/4838"}],"wp:attachment":[{"href":"https:\/\/lecercleetlecarre.fr\/index.php\/wp-json\/wp\/v2\/media?parent=3031"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lecercleetlecarre.fr\/index.php\/wp-json\/wp\/v2\/categories?post=3031"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lecercleetlecarre.fr\/index.php\/wp-json\/wp\/v2\/tags?post=3031"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}