{"id":5205,"date":"2016-12-31T13:15:44","date_gmt":"2016-12-31T13:15:44","guid":{"rendered":"http:\/\/blogs.scienceforums.net\/ajb\/?p=5205"},"modified":"2016-12-31T13:15:44","modified_gmt":"2016-12-31T13:15:44","slug":"mrs-brown-on-relativity","status":"publish","type":"post","link":"http:\/\/blogs.scienceforums.net\/ajb\/2016\/12\/31\/mrs-brown-on-relativity\/","title":{"rendered":"Mrs Brown on relativity"},"content":{"rendered":"<table border=\"0\">\n<tbody>\n<tr>\n<td><img decoding=\"async\" src=\"http:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/a\/a0\/Einstein_patentoffice.jpg\/459px-Einstein_patentoffice.jpg\" alt=\"\" width=\"300\" \/><\/td>\n<td style=\"vertical-align: top\">I briefly watched a few moments of Mrs Brown&#8217;s Boys Christmas special 2016; a comedy program on the BBC.<\/p>\n<p>Agnes Brown\u2019s grandson Bono asked his grandmother about Einstein&#8217;s theory of relativity. The joke is that this is far to complicated for an old Irish Granny to answer.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>This made me think. Einstein first published on special relativity in 1905 and the field equations for general relativity were published in 1916. So humanity has had knowledge of Einstein&#8217;s relativity for 100 years now, yet Mrs Brown was unable to say anything!<\/p>\n<p>Not that we should expect everyone to have a detailed mathematical knowledge of Einstein&#8217;s relativity, but should just about everyone be able to say something?<\/p>\n<p><strong>Special relativity<\/strong><br \/>\nSpecial relativity is based on two postulates &#8211; that then lead to a consistent mathematical description in terms of differential geometry, but we should ignore that for now &#8211; that can be paraphrased as follows<\/p>\n<ol>\n<li>\u00a0The laws of physics are the same for all non-accelerating observers.<\/li>\n<li>\u00a0All\u00a0 non-accelerating observers measure the speed of light to be the same,\u00a0 irrespective of the source of light.<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<p>Even more pedagogically, all observers that are not experiencing a net force are `equally as good&#8217; as far as determining the laws of physics are concerned,  and on top of that, light waves travel at a fixed speed as measured by these privileged observers.<\/p>\n<p><strong>General relativity <\/strong><br \/>\nThis is a bit harder to paraphrase, but basically we  have three key features<\/p>\n<ol>\n<li> All observers (not just the non-accelerating ones) are equally as good for determining the laws of physics.<\/li>\n<li>Space-time is curved and the force of gravity is the `bending&#8217; of space and time.<\/li>\n<li> In `small enough&#8217; regions, the non-gravitational laws of physics reduce to that of special relativity.<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<p>Again, all this can be made mathematically precise.<\/p>\n<p><strong>Are we expecting too much?<\/strong><br \/>\nI think it is too much to expect any real knowledge of Einstein&#8217;s relativity from the general public. So, we should not ask for this, but only a vague idea of the ideas from most people. <\/p>\n<p>From my own perspective it is all differential geometry \ud83d\ude42 <\/p>\n","protected":false},"excerpt":{"rendered":"<p>I briefly watched a few moments of Mrs Brown&#8217;s Boys Christmas special 2016; a comedy program on the BBC. Agnes Brown\u2019s grandson Bono asked his grandmother about Einstein&#8217;s theory of relativity. The joke is that this is far to complicated for an old Irish Granny to answer. This made me think. Einstein first published on &hellip; <a href=\"http:\/\/blogs.scienceforums.net\/ajb\/2016\/12\/31\/mrs-brown-on-relativity\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Mrs Brown on relativity<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-5205","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"http:\/\/blogs.scienceforums.net\/ajb\/wp-json\/wp\/v2\/posts\/5205","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/blogs.scienceforums.net\/ajb\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/blogs.scienceforums.net\/ajb\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/blogs.scienceforums.net\/ajb\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"http:\/\/blogs.scienceforums.net\/ajb\/wp-json\/wp\/v2\/comments?post=5205"}],"version-history":[{"count":11,"href":"http:\/\/blogs.scienceforums.net\/ajb\/wp-json\/wp\/v2\/posts\/5205\/revisions"}],"predecessor-version":[{"id":5216,"href":"http:\/\/blogs.scienceforums.net\/ajb\/wp-json\/wp\/v2\/posts\/5205\/revisions\/5216"}],"wp:attachment":[{"href":"http:\/\/blogs.scienceforums.net\/ajb\/wp-json\/wp\/v2\/media?parent=5205"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/blogs.scienceforums.net\/ajb\/wp-json\/wp\/v2\/categories?post=5205"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/blogs.scienceforums.net\/ajb\/wp-json\/wp\/v2\/tags?post=5205"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}