{"id":341,"date":"2007-02-12T09:45:31","date_gmt":"2007-02-12T16:45:31","guid":{"rendered":"http:\/\/qpr.ca\/blog\/?p=341"},"modified":"2007-10-05T15:32:30","modified_gmt":"2007-10-05T22:32:30","slug":"hours-of-daylight","status":"publish","type":"post","link":"https:\/\/qpr.ca\/blogs\/2007\/02\/12\/hours-of-daylight\/","title":{"rendered":"Hours of Daylight"},"content":{"rendered":"<p>Thanks to Zac at squareCircleZ for <a href=\"http:\/\/www.squarecirclez.com\/blog\/gaisma-real-life-sine-graphs\/548\">pointing out<\/a> the dawn and dusk graphs at <a href=\"http:\/\/www.gaisma.com\/en\">Gaisma<\/a> as real-life examples of approximate sine graphs.<\/p>\n<p>In fact the true time of noon appears to oscillate slightly with a 6 month period so that the Tokyo graphs are modelled pretty well by 6+1.5sin(2pix\/12)-0.15sin(2pix\/6) &amp; -6-1.5sin(2pix\/12)-0.15sin(2pix\/6).<\/p>\n<p>(<strong>Update<\/strong>: thanks to zac also for pointing out in the comment below that I should either have used cosines or have said &#8220;where x is the number of months since the spring equinox&#8221;)<\/p>\n<p>It will be neat to be able to give Gaisma as a source of reference data for the hours of daylight modelling examples in my precalculus classes.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Thanks to Zac at squareCircleZ for pointing out the dawn and dusk graphs at Gaisma as real-life examples of approximate sine graphs. In fact the true time of noon appears to oscillate slightly with a 6 month period so that &hellip; <a href=\"https:\/\/qpr.ca\/blogs\/2007\/02\/12\/hours-of-daylight\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,8],"tags":[],"class_list":["post-341","post","type-post","status-publish","format-standard","hentry","category-education","category-mathematics"],"_links":{"self":[{"href":"https:\/\/qpr.ca\/blogs\/wp-json\/wp\/v2\/posts\/341","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/qpr.ca\/blogs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qpr.ca\/blogs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qpr.ca\/blogs\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/qpr.ca\/blogs\/wp-json\/wp\/v2\/comments?post=341"}],"version-history":[{"count":0,"href":"https:\/\/qpr.ca\/blogs\/wp-json\/wp\/v2\/posts\/341\/revisions"}],"wp:attachment":[{"href":"https:\/\/qpr.ca\/blogs\/wp-json\/wp\/v2\/media?parent=341"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qpr.ca\/blogs\/wp-json\/wp\/v2\/categories?post=341"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qpr.ca\/blogs\/wp-json\/wp\/v2\/tags?post=341"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}