{"id":1188,"date":"2009-06-28T09:13:13","date_gmt":"2009-06-28T16:13:13","guid":{"rendered":"http:\/\/studionebula.com\/blog\/2009\/06\/28\/is-gravity-different-in-your-neighborhood"},"modified":"2009-06-28T09:13:13","modified_gmt":"2009-06-28T16:13:13","slug":"is-gravity-different-in-your-neighborhood","status":"publish","type":"post","link":"https:\/\/studionebula.com\/blog\/2009\/06\/28\/is-gravity-different-in-your-neighborhood","title":{"rendered":"Is Gravity Different In Your Neighborhood?"},"content":{"rendered":"<p>We bought a cheap digital scale recently for weighing Zed. Zed&#8217;s on a weight-reducing diet and we wanted a means to verify that it&#8217;s actually working. The scale came with a better-than-average instruction manual (better than the average instruction manual for a cheap Chinese-made product, that is) which contains one very strange paragraph, which I will reproduce here verbatim without sprinking it with the &#8220;[sic]&#8221;s that it merits:<\/p>\n<p><em>CALIBRATION<\/em><\/p>\n<p><em>When to calibrate &#8211; calibration is almost never required.<\/em><\/p>\n<p><em>If the scale is inaccurate, calibration may be desired when the scale is first set up for use, or if the scale is moved to a different altitude or gravitation. This is necessary because the weight of a mass in one location is not necessarily the same in another location. Also, with time and use, mechanical deviations can occur.<\/em><\/p>\n<p>It&#8217;s been many, many years since either my high-school or college Physics classes, but I&#8217;m pretty sure that I remember that there is no such thing as &#8220;a different gravitation&#8221;, at least not within our universe. In fact, had you asked me 25-odd years ago, I could have rattled off the Universal Gravitational Constant to at least three significant figures.<\/p>\n<p>Now, technically speaking, it is accurate that &#8220;the weight of a mass in one one location is not necessarily the same in another location&#8221; if you interpret &#8220;weight&#8221; to mean &#8220;what a scale says when you put a mass on it&#8221;. That&#8217;s why physicists et al use the term mass and not weight. But this variation is only relevant if you&#8217;re talking about moving the mass from the surface of the planet to far above it, like taking something from Cape Kennedy to the ISS with the space shuttle. I&#8217;m quite sure that moving something from, say, a sea-level freight dock on the coast of China to Boulder, where the official altitude is 5430 feet, would not produce a measureable change in its mass. Moreover, that change in altitude most certainly wouldn&#8217;t produce a change in weight that would register within the stated accuracy of this cheap scale (which is seemingly two grams, although it&#8217;s not clear whether the figure stated in the Specifications is accuracy or resolution, but I digress).<\/p>\n","protected":false},"excerpt":{"rendered":"<p>We bought a cheap digital scale recently for weighing Zed. Zed&#8217;s on a weight-reducing diet and we wanted a means to verify that it&#8217;s actually working. The scale came with a better-than-average instruction manual (better than the average instruction manual for a cheap Chinese-made product, that is) which contains one very strange paragraph, which I&hellip; <a class=\"more-link\" href=\"https:\/\/studionebula.com\/blog\/2009\/06\/28\/is-gravity-different-in-your-neighborhood\">Continue reading <span class=\"screen-reader-text\">Is Gravity Different In Your Neighborhood?<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1188","post","type-post","status-publish","format-standard","hentry","category-uncategorized","entry"],"_links":{"self":[{"href":"https:\/\/studionebula.com\/blog\/wp-json\/wp\/v2\/posts\/1188","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/studionebula.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/studionebula.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/studionebula.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/studionebula.com\/blog\/wp-json\/wp\/v2\/comments?post=1188"}],"version-history":[{"count":0,"href":"https:\/\/studionebula.com\/blog\/wp-json\/wp\/v2\/posts\/1188\/revisions"}],"wp:attachment":[{"href":"https:\/\/studionebula.com\/blog\/wp-json\/wp\/v2\/media?parent=1188"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/studionebula.com\/blog\/wp-json\/wp\/v2\/categories?post=1188"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/studionebula.com\/blog\/wp-json\/wp\/v2\/tags?post=1188"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}