{"id":2452,"date":"2008-04-02T10:45:17","date_gmt":"2008-04-02T10:45:17","guid":{"rendered":"http:\/\/scienceblogs.com\/principles\/2008\/04\/02\/dorky-poll-si-or-cgs\/"},"modified":"2008-04-02T10:45:17","modified_gmt":"2008-04-02T10:45:17","slug":"dorky-poll-si-or-cgs","status":"publish","type":"post","link":"http:\/\/chadorzel.com\/principles\/2008\/04\/02\/dorky-poll-si-or-cgs\/","title":{"rendered":"Dorky Poll: SI or CGS?"},"content":{"rendered":"

I have a doctor’s appointment this morning, and then class, so here’s another Dorky Poll inspired by the fact that I’m teaching intro E&M:<\/p>\n

\n

What system of units do you prefer for E&M: SI, or CGS?<\/p>\n<\/blockquote>\n

This is even dorkier than usual, so I suppose I should provide some context…<\/p>\n

<\/p>\n

The CGS system of units<\/a> uses Centimeters, Grams, and Seconds as the base usints for everything, as opposed to the metere, kilograms, and seconds of the Systeme Internationale (also called MKS in some places). This doesn’t make very much difference in mechanics, but it’s a big deal in electromagnetism, because the units generally associated with CGS there are very different, and change the form of the equations.<\/p>\n

The biggest difference is the elimination of a factor of 1\/4πεo<\/sub> from Coulomb’s Law and related equations. Basically, the Coulomb constant is set equal to one, which simplifies a lot of equations.<\/p>\n

For this reason, CGS units remain popular in a lot of E&M books. <\/p>\n

Personally, I favor SI units, because nobody in the real world uses “statvolts” or “statcoulombs” to measure anything, and the unit conversions are a bitch. It’s easier to just cope with the 1\/4πεo<\/sub>, and directly apply the results. But then, I’m an experimental atomic physicists– theorists and astronomers may have a different view.<\/p>\n","protected":false},"excerpt":{"rendered":"

I have a doctor’s appointment this morning, and then class, so here’s another Dorky Poll inspired by the fact that I’m teaching intro E&M: What system of units do you prefer for E&M: SI, or CGS? This is even dorkier than usual, so I suppose I should provide some context…<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"1","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13,7],"tags":[],"class_list":["post-2452","post","type-post","status-publish","format-standard","hentry","category-education","category-physics","entry"],"_links":{"self":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/2452","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/comments?post=2452"}],"version-history":[{"count":0,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/2452\/revisions"}],"wp:attachment":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/media?parent=2452"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/categories?post=2452"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/tags?post=2452"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}