{"version":"1.0","provider_name":"\u00c9tienne Ghys","provider_url":"https:\/\/perso.ens-lyon.fr\/ghys","author_name":"ghys","author_url":"https:\/\/perso.ens-lyon.fr\/ghys\/author\/ghys\/","title":"Math in your sanitary pass - \u00c9tienne Ghys","type":"rich","width":600,"height":338,"html":"<blockquote class=\"wp-embedded-content\" data-secret=\"ysKtiVNItp\"><a href=\"https:\/\/perso.ens-lyon.fr\/ghys\/2021\/09\/15\/2200\/\">Math in your sanitary pass<\/a><\/blockquote><iframe sandbox=\"allow-scripts\" security=\"restricted\" src=\"https:\/\/perso.ens-lyon.fr\/ghys\/2021\/09\/15\/2200\/embed\/#?secret=ysKtiVNItp\" width=\"600\" height=\"338\" title=\"\u00ab\u00a0Math in your sanitary pass\u00a0\u00bb &#8212; \u00c9tienne Ghys\" data-secret=\"ysKtiVNItp\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" class=\"wp-embedded-content\"><\/iframe><script>\n\/*! This file is auto-generated *\/\n!function(d,l){\"use strict\";l.querySelector&&d.addEventListener&&\"undefined\"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!\/[^a-zA-Z0-9]\/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret=\"'+t.secret+'\"]'),o=l.querySelectorAll('blockquote[data-secret=\"'+t.secret+'\"]'),c=new RegExp(\"^https?:$\",\"i\"),i=0;i<o.length;i++)o[i].style.display=\"none\";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute(\"style\"),\"height\"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):\"link\"===t.message&&(r=new URL(s.getAttribute(\"src\")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener(\"message\",d.wp.receiveEmbedMessage,!1),l.addEventListener(\"DOMContentLoaded\",function(){for(var e,t,s=l.querySelectorAll(\"iframe.wp-embedded-content\"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute(\"data-secret\"))||(t=Math.random().toString(36).substring(2,12),e.src+=\"#?secret=\"+t,e.setAttribute(\"data-secret\",t)),e.contentWindow.postMessage({message:\"ready\",secret:t},\"*\")},!1)))}(window,document);\n<\/script>\n","description":"https:\/\/www.lemonde.fr\/sciences\/article\/2021\/09\/15\/des-maths-dans-votre-passe-sanitaire_6094702_1650684.html QR codes are loaded with math. The health pass consists of 7,225 little white or black squares, arranged in 85 rows and 85 columns, that encode vaccination status, or test result, or certificate of recovery. This poses some very interesting mathematical and computer problems. The first problem is geometric. The optical reader that scans &hellip; Continuer la lecture de &rarr;"}