{"id":9245,"date":"2021-04-04T20:16:16","date_gmt":"2021-04-04T11:46:16","guid":{"rendered":"https:\/\/people.utm.my\/razman-ayop\/?p=9245"},"modified":"2021-04-04T20:16:38","modified_gmt":"2021-04-04T11:46:38","slug":"from-sundials-to-atomic-clocks-how-the-universe-shapes-our-understanding-of-time","status":"publish","type":"post","link":"https:\/\/people.utm.my\/razman-ayop\/from-sundials-to-atomic-clocks-how-the-universe-shapes-our-understanding-of-time\/","title":{"rendered":"From Sundials to Atomic Clocks: How the Universe Shapes Our Understanding of Time"},"content":{"rendered":"\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=\"From Sundials to Atomic Clocks: How the Universe Shapes Our Understanding of Time\" width=\"1080\" height=\"608\" src=\"https:\/\/www.youtube.com\/embed\/lVWUyK_M934?feature=oembed\"  allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<p>As early as 3500 BCE, the Egyptians began building obelisks to divide their days into parts resembling the hours we know today. The moving shadows created by the Sun hitting the obelisk helped to divide morning from afternoon, while the length of the noontime shadow showed the year&#8217;s longest and shortest days. This is the same principle behind sundials, which you may be more familiar with. But watching shadows move across the Earth isn\u2019t the only way the sky can help us keep time. Around the same time the Egyptians were building obelisks, a 366-day calendar structured on the movements of the Sun and the moon was being developed in China. But after a few centuries of use, astronomers began noticing that the calendar became inaccurate every 300 years or so. The reason? Well, the stars, including the Sun, aren\u2019t as \u201cfixed\u201d in the night sky as they appear to be. There\u2019s movement happening; something that we call precession. As the Earth\u2019s rotational axis slowly moves, the stars shift in our night sky. About every 26,000 years or so, we get a new view of the stars. Today, most of us know that Polaris is the North Star. But 26,000 years ago, Thuban\u2014 a star in the &#8216;tail&#8217; of the constellation Draco\u2014was the marker of the poles! By the 5th century CE, Chinese scholars had figured out the whole precession problem and factored it into their calendar. And roughly 500 years later, one of the greatest time-keeping achievements of ancient China was unveiled: a five-story astronomical clock tower. This mechanical structure ran on a day and night time-keeping wheel that was powered by water!<\/p>\n","protected":false},"excerpt":{"rendered":"<p>As early as 3500 BCE, the Egyptians began building obelisks to divide their days into parts resembling the hours we know today. The moving shadows created by the Sun hitting the obelisk helped to divide morning from afternoon, while the length of the noontime shadow showed the year&#8217;s longest and shortest days. This is the [&hellip;]<\/p>\n","protected":false},"author":24954,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"video","meta":{"_et_pb_use_builder":"off","_et_pb_old_content":"","_et_gb_content_width":"","_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-9245","post","type-post","status-publish","format-video","hentry","category-variety","post_format-post-format-video"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/people.utm.my\/razman-ayop\/wp-json\/wp\/v2\/posts\/9245","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/people.utm.my\/razman-ayop\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/people.utm.my\/razman-ayop\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/people.utm.my\/razman-ayop\/wp-json\/wp\/v2\/users\/24954"}],"replies":[{"embeddable":true,"href":"https:\/\/people.utm.my\/razman-ayop\/wp-json\/wp\/v2\/comments?post=9245"}],"version-history":[{"count":1,"href":"https:\/\/people.utm.my\/razman-ayop\/wp-json\/wp\/v2\/posts\/9245\/revisions"}],"predecessor-version":[{"id":9246,"href":"https:\/\/people.utm.my\/razman-ayop\/wp-json\/wp\/v2\/posts\/9245\/revisions\/9246"}],"wp:attachment":[{"href":"https:\/\/people.utm.my\/razman-ayop\/wp-json\/wp\/v2\/media?parent=9245"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/people.utm.my\/razman-ayop\/wp-json\/wp\/v2\/categories?post=9245"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/people.utm.my\/razman-ayop\/wp-json\/wp\/v2\/tags?post=9245"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}