{"id":1276,"date":"2025-04-22T17:41:23","date_gmt":"2025-04-22T17:41:23","guid":{"rendered":"https:\/\/larrykooper.com\/?p=1276"},"modified":"2025-04-22T17:41:23","modified_gmt":"2025-04-22T17:41:23","slug":"33-claudius-ptolemy-c-90-ad-c-168-ad","status":"publish","type":"post","link":"https:\/\/larrykooper.com\/index.php\/2025\/04\/22\/33-claudius-ptolemy-c-90-ad-c-168-ad\/","title":{"rendered":"33. Claudius Ptolemy (c. 90 AD &#8211; c.168 AD)"},"content":{"rendered":"\n<p>Original Language: Greek<\/p>\n\n\n\n<p>I read the <strong>Almagest<\/strong> on the Internet Archive. (<a href=\"http:\/\/archive.org\">archive.org<\/a>)<\/p>\n\n\n\n<p>Sidebar: I am very thankful for the Internet Archive. I just donated a small amount of money to them and if you can, I urge you to.<\/p>\n\n\n\n<p>The ancients rendered years by the Roman Emperors. For example<br>Year 11 of Hadrian<br>Hadrian 9<br>Antonine 14<br>and in Egypt they had a month named Thoth.<\/p>\n\n\n\n<p>Ptolemy believed the world was spherical. And one of his proofs of that is time differences between the east and the west. But his model was geocentric. There is a good deal of geometry, and geometrical proofs, in his book. They didn&#8217;t know at that time that anybody lived south of the Equator. Ptolemy was a genius. He also knew that there were 6 months of light and 6 months of darkness at the North Pole. And I see why Ptolemy is on the list of great books.<\/p>\n\n\n\n<p>The <strong>Almagest<\/strong> is an awesome book. I&#8217;m happy the Arabs preserved it. Even though Ptolemy was wrong about the geocentric part, it is full of detailed and (presumably) accurate observations, and geometric proofs.<\/p>\n\n\n\n<p><strong>Last thoughts on Ptolemy<\/strong><br>Wow. I&#8217;m impressed. And an appendix explained you could use Ptolemy&#8217;s calculations in the Copernican heliocentric system.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Original Language: Greek I read the Almagest on the Internet Archive. (archive.org) Sidebar: I am very thankful for the Internet Archive. I just donated a small amount of money to them and if you can, I urge you to. The ancients rendered years by the Roman Emperors. For exampleYear 11 of HadrianHadrian 9Antonine 14and in [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-1276","post","type-post","status-publish","format-standard","hentry","category-great-books"],"_links":{"self":[{"href":"https:\/\/larrykooper.com\/index.php\/wp-json\/wp\/v2\/posts\/1276","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/larrykooper.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/larrykooper.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/larrykooper.com\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/larrykooper.com\/index.php\/wp-json\/wp\/v2\/comments?post=1276"}],"version-history":[{"count":2,"href":"https:\/\/larrykooper.com\/index.php\/wp-json\/wp\/v2\/posts\/1276\/revisions"}],"predecessor-version":[{"id":1278,"href":"https:\/\/larrykooper.com\/index.php\/wp-json\/wp\/v2\/posts\/1276\/revisions\/1278"}],"wp:attachment":[{"href":"https:\/\/larrykooper.com\/index.php\/wp-json\/wp\/v2\/media?parent=1276"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/larrykooper.com\/index.php\/wp-json\/wp\/v2\/categories?post=1276"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/larrykooper.com\/index.php\/wp-json\/wp\/v2\/tags?post=1276"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}