{"id":56,"date":"2007-09-28T00:11:01","date_gmt":"2007-09-28T05:11:01","guid":{"rendered":"http:\/\/arxivblog.com\/?p=56"},"modified":"2007-09-28T00:16:38","modified_gmt":"2007-09-28T05:16:38","slug":"56","status":"publish","type":"post","link":"http:\/\/arxivblog.com\/?p=56","title":{"rendered":"Halting the horrible kilogram shrink"},"content":{"rendered":"<p>The kilogram is a-shrinkin&#8217; and ain&#8217;t nobody sure why. The problem is the way it is defined: the mass of a lump o&#8217; metal stored in a vault in Paris. That&#8217;s no good cos a few atoms rub off each time it is picked up and others seem to fall off even when it ain&#8217;t picked up. In the last few years, it&#8217;s lost about the mass of a grain of sand.<\/p>\n<p>Ain&#8217;t there a better way to define the kilogram? There sure is and shortage of em either. In November the world&#8217;s heavyweight experts are meeting in Paris to select the best definition by a vote or a toss of a coin or by some other method they ain&#8217;t told us about.<\/p>\n<p>So between now and then expect to see plenty of elbowin&#8217; n&#8217; jostlin as the various definitions jockey for position. This week it&#8217;s the turn of Ronald &#8220;McDonald&#8221; Fox and Theodore &#8220;Over-the&#8221; Hill at Georgia Tech in Atlanta to pitch their definition.<\/p>\n<p>They reckon that best way to define a kilogram  is to fix the value of <a href=\"http:\/\/arxivblog.com\/?p=34\">Avogadro&#8217;s constant<\/a>, the number of atoms in 12 grams of carbon-12,  at 84446886^3. That would make one gram exactly equal to the mass of 18 x 14074481^3 atoms of carbon-12.<\/p>\n<p>It&#8217;s a good try but ain&#8217;t nobody gonna be happy with that definition. Why use carbon-12 and not silicon which is the current darling of most heavyweights in physics?  And why rely on countin&#8217; when you can  define a kilogram in terms of its equivalent energy, thereby linking it via relativity to another fundamental:  the Planck constant?<\/p>\n<p>It&#8217;s all shapin up nicely for one helluva mudwrestle in Paris in November. All we need is a unit of hellraisin so we can work out the winner.<\/p>\n<p>Ref: <a href=\"http:\/\/arxiv.org\/abs\/0709.2576\">arxiv.org\/abs\/0709.2576<\/a>:  A Better Definition of the Kilogram<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The kilogram is a-shrinkin&#8217; and ain&#8217;t nobody sure why. The problem is the way it is defined: the mass of a lump o&#8217; metal stored in a vault in Paris. That&#8217;s no good cos a few atoms rub off each time it is picked up and others seem to fall off even when it ain&#8217;t [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10,6,5],"tags":[],"class_list":["post-56","post","type-post","status-publish","format-standard","hentry","category-fightin","category-hellraisin","category-secrets"],"_links":{"self":[{"href":"http:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/posts\/56","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=56"}],"version-history":[{"count":0,"href":"http:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/posts\/56\/revisions"}],"wp:attachment":[{"href":"http:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=56"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=56"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=56"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}