{"id":39858,"date":"2022-10-17T14:48:52","date_gmt":"2022-10-17T14:48:52","guid":{"rendered":"https:\/\/www.bwsailing.com\/cc\/?p=39858"},"modified":"2022-10-17T14:50:23","modified_gmt":"2022-10-17T14:50:23","slug":"mindbender-402","status":"publish","type":"post","link":"https:\/\/www.bwsailing.com\/cc\/2022\/10\/mindbender-402\/","title":{"rendered":"Mindbender"},"content":{"rendered":"<p>Where on a sailboat would you find a broad-seam?<\/p>\n<p>&nbsp;<\/p>\n<p><b>Send your answers to cruisingcompass@bwsailing.com. A winner will be drawn from the correct answers and will win a subscription to the digital version of Blue Water Sailing.<\/b><\/p>\n<p>&nbsp;<\/p>\n<p>Congratulations to Sid Nathan, Padstow, England, who did some homework to answer last week&#8217;s Mindbender question.\u00a0 &#8220;According to Wikipedia and other sources, the first person to create a grid on a map was the Greek philosopher Eratosthenes in the third century BCE.\u00a0 Another Greek philosopher in the same era, Hipparchus, was the first to use trigonometry to find a position on the grid. Both relied on the idea of latitude, or distance from the equator, that was developed earlier by the Phoenicians, who used astronomical observation &#8211;celestial navigation&#8211; to determine their latitude. Determining longitude to get an accurate fix was not possible until German mathematician Gemma Frisius proposed using time differentials to measure a distance east or west from a prime meridian. But time keeping was inexact at sea until the 1750s when Englishman John Harrison invented a highly accurate chronometer that could maintain Greenwich Mean Time anywhere in the world and thus provide navigators with the time differential needed to calculate longitude.&#8221;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Where on a sailboat would you find a broad-seam? &nbsp; Send your answers to cruisingcompass@bwsailing.com. A winner will be drawn from the correct answers and will win a subscription to the digital version of Blue Water Sailing. &nbsp; Congratulations to Sid Nathan, Padstow, England, who did some homework to answer last week&#8217;s Mindbender question.\u00a0 &#8220;According to Wikipedia and other sources, the first person to create a grid on a map was the Greek philosopher Eratosthenes in the third century BCE.\u00a0 Another Greek philosopher in the same era, Hipparchus, was the first to use trigonometry to find a position on the grid. Both relied on the idea of latitude, or distance from the equator, that was developed earlier by the Phoenicians, who used astronomical observation &#8211;celestial navigation&#8211; to determine their latitude. Determining longitude to get an accurate fix was not possible until German mathematician Gemma Frisius proposed using time differentials to measure a distance east or west from a prime meridian. But time keeping was inexact at sea until the 1750s when Englishman John Harrison invented a highly accurate chronometer that could maintain Greenwich Mean Time anywhere in the world and thus provide navigators with the time differential needed to calculate &#8230;<\/p>\n","protected":false},"author":3,"featured_media":32719,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[5],"tags":[],"_links":{"self":[{"href":"https:\/\/www.bwsailing.com\/cc\/wp-json\/wp\/v2\/posts\/39858"}],"collection":[{"href":"https:\/\/www.bwsailing.com\/cc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bwsailing.com\/cc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bwsailing.com\/cc\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bwsailing.com\/cc\/wp-json\/wp\/v2\/comments?post=39858"}],"version-history":[{"count":4,"href":"https:\/\/www.bwsailing.com\/cc\/wp-json\/wp\/v2\/posts\/39858\/revisions"}],"predecessor-version":[{"id":39862,"href":"https:\/\/www.bwsailing.com\/cc\/wp-json\/wp\/v2\/posts\/39858\/revisions\/39862"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bwsailing.com\/cc\/wp-json\/wp\/v2\/media\/32719"}],"wp:attachment":[{"href":"https:\/\/www.bwsailing.com\/cc\/wp-json\/wp\/v2\/media?parent=39858"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bwsailing.com\/cc\/wp-json\/wp\/v2\/categories?post=39858"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bwsailing.com\/cc\/wp-json\/wp\/v2\/tags?post=39858"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}