1.0FSTM FRhttps://www.uni.lu/fstm-frFSTM FRhttps://www.uni.lu/fstm-frrich600338<blockquote class="wp-embedded-content" data-secret="xu6OkJ4u4D"><a href="https://www.uni.lu/fstm-fr/events/geometry-topology-seminar/">Geometry-Topology seminar</a></blockquote><iframe sandbox="allow-scripts" security="restricted" src="https://www.uni.lu/fstm-fr/events/geometry-topology-seminar/embed/#?secret=xu6OkJ4u4D" width="600" height="338" title="« Geometry-Topology seminar » — FSTM FR" data-secret="xu6OkJ4u4D" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" class="wp-embedded-content"></iframe><script> /*! This file is auto-generated */ !function(c,d){"use strict";var e=!1,o=!1;if(d.querySelector)if(c.addEventListener)e=!0;if(c.wp=c.wp||{},c.wp.receiveEmbedMessage);else if(c.wp.receiveEmbedMessage=function(e){var t=e.data;if(!t);else if(!(t.secret||t.message||t.value));else if(/[^a-zA-Z0-9]/.test(t.secret));else{for(var r,s,a,i=d.querySelectorAll('iframe[data-secret="'+t.secret+'"]'),n=d.querySelectorAll('blockquote[data-secret="'+t.secret+'"]'),o=new RegExp("^https?:$","i"),l=0;l<n.length;l++)n[l].style.display="none";for(l=0;l<i.length;l++)if(r=i[l],e.source!==r.contentWindow);else{if(r.removeAttribute("style"),"height"===t.message){if(1e3<(s=parseInt(t.value,10)))s=1e3;else if(~~s<200)s=200;r.height=s}if("link"===t.message)if(s=d.createElement("a"),a=d.createElement("a"),s.href=r.getAttribute("src"),a.href=t.value,!o.test(a.protocol));else if(a.host===s.host)if(d.activeElement===r)c.top.location.href=t.value}}},e)c.addEventListener("message",c.wp.receiveEmbedMessage,!1),d.addEventListener("DOMContentLoaded",t,!1),c.addEventListener("load",t,!1);function t(){if(o);else{o=!0;for(var e,t,r,s=-1!==navigator.appVersion.indexOf("MSIE 10"),a=!!navigator.userAgent.match(/Trident.*rv:11\./),i=d.querySelectorAll("iframe.wp-embedded-content"),n=0;n<i.length;n++){if(!(r=(t=i[n]).getAttribute("data-secret")))r=Math.random().toString(36).substr(2,10),t.src+="#?secret="+r,t.setAttribute("data-secret",r);if(s||a)(e=t.cloneNode(!0)).removeAttribute("security"),t.parentNode.replaceChild(e,t);t.contentWindow.postMessage({message:"ready",secret:r},"*")}}}}(window,document); </script> https://www.uni.lu/wp-content/uploads/sites/20/2026/03/03111744/FSTM_SM-Profile_1600x1600px-scaled.jpg25602560The « Spherics » by Menelaus of Alexandria (1st-2nd c. A.D.) is probably the most important treatise ever written on spherical geometry. It is a profound work, introducing new methods in geometry, intrinsic to the sphere, containing 91 propositions, some of which are very difficult to prove. An edition, from Arabic texts (the Greek original does not survive), was just published by De Gruyter, in their series Scientia Graeco-Arabica, No. 21