There are three main errors in that sentence.<\/p>\n
One is more a matter of poor wording but still an error, the second is perhaps just a misprint, and the third is I think at the heart of many misunderstandings of Relativity.<\/p>\n
First the minor stuff:<\/p>\n
What General Relativity predicts for an orbiting<\/em> satellite can be written as a sum of two parts, one gravitational (which is the same as what GR predicts for a stationary<\/em> clock at the same height as the satellite) and the other sometimes called kinematic, but that breakdown is only approximate as there are other higher order terms involved as well (which include products of gravitational and velocity factors). What the quoted sentence has called the prediction of GR is just the gravitational part (which does indeed contribute about 45 microseconds to the daily time advance of the satellite clock). But GR also predicts the kinematic part (of about 17 microseconds per day of retardation), as well as those smaller additional terms, and so it is wrong to identify just the gravitational term as what GR predicts rather than as what GR would predict if the satellite were stationary (and NOT \u201corbiting\u201d). The writer also left off the \u201cper day\u201d in describing the pure gravitational term, but I am sure that was just a misprint.<\/p>\n But, as I said, all that, though definitely wrong, is relatively minor stuff.<\/p>\n The more serious error is in the description of having a daily advance (or in the purely kinematical part a daily retardation) as ticking “faster” (or slower). It would be perfectly ok if you said ticking faster (or slower) on average<\/em>, and leaving off the \u201con average\u201d might seem like a small thing; but it is a serious error because it leads to the wrong idea that it means ticking faster (or slower) all the time. And the reason that is wrong is because different observers (while agreeing on the accumulated time differences recorded on two clocks between times when they are together) may disagree on whether one was always running slower or sometimes slower and sometimes faster (by amounts that give the same net total as in the always slower case). And we have no way of deciding which of them is \u201cright\u201d.<\/p>\n Source: (1000) In the twin paradox it is often stated that the clocks can only be compared at the same location. Why can\u2019t the clocks be compared at space stations synchronized with the earth clock on the travelling twin\u2019s journey? – Philosophy of Relativity – Quora<\/a><\/em><\/p>\n","protected":false},"excerpt":{"rendered":" There are three main errors in that sentence. One is more a matter of poor wording but still an error, the second is perhaps just a misprint, and the third is I think at the heart of many misunderstandings of Relativity. First the minor stuff: What General Relativity predicts for an orbiting satellite can be … Continue reading What’s wrong with saying “General relativity says that the orbiting clocks should tick about 45 millionths of a second faster than they would on Earth”?<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"topics":[],"class_list":["post-1139","post","type-post","status-publish","format-standard","hentry","category-all"],"_links":{"self":[{"href":"https:\/\/qpr.ca\/blogs\/physics\/wp-json\/wp\/v2\/posts\/1139","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/qpr.ca\/blogs\/physics\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qpr.ca\/blogs\/physics\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qpr.ca\/blogs\/physics\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/qpr.ca\/blogs\/physics\/wp-json\/wp\/v2\/comments?post=1139"}],"version-history":[{"count":1,"href":"https:\/\/qpr.ca\/blogs\/physics\/wp-json\/wp\/v2\/posts\/1139\/revisions"}],"predecessor-version":[{"id":1140,"href":"https:\/\/qpr.ca\/blogs\/physics\/wp-json\/wp\/v2\/posts\/1139\/revisions\/1140"}],"wp:attachment":[{"href":"https:\/\/qpr.ca\/blogs\/physics\/wp-json\/wp\/v2\/media?parent=1139"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qpr.ca\/blogs\/physics\/wp-json\/wp\/v2\/categories?post=1139"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qpr.ca\/blogs\/physics\/wp-json\/wp\/v2\/tags?post=1139"},{"taxonomy":"topics","embeddable":true,"href":"https:\/\/qpr.ca\/blogs\/physics\/wp-json\/wp\/v2\/topics?post=1139"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}