Exhibition in Rome displays for the first time documents of Galileo's professor (Video) German Jesuit mathematician Christopher Clavius introduced the Gregorian calendar. enero 11, 2015 00:00ZENIT StaffArchives Share this Entry To view the video click here – Publicaciones relacionadas: Mideast Peace Seems Further Away, Says L'Osservatore Romano Brazilian Bishops Ask Priests to Stay Out of Politics Christmas Message From Hong Kong Cardinal A lesson on how to get the Pope to greet your parish (Video) enero 11, 2015 00:00Archives ZENIT Staff View all articles