http://www.metafilter.com/tags/googlecalculator Posts tagged with 'googlecalculator' at MetaFilter. Tue, 30 Nov 2004 19:33:20 -0800 Tue, 30 Nov 2004 19:33:20 -0800 en-us http://blogs.law.harvard.edu/tech/rss 60 http://www.metafilter.com/37363/Stupid%2DGoogle%2DTricks Does relativity have any practical significance? In fact, relativity had to be <a href="http://www-astronomy.mps.ohio-state.edu/~pogge/Ast162/Unit5/gps.html">taken into account</a> by the designers of the Global Positioning System. The GPS satellites are affected both by <a href="http://www2.slac.stanford.edu/vvc/theory/relativity.html">special relativity</a> (since the satellites are moving, clocks aboard them appear to run slower as seen from the ground), and by <a href="http://archive.ncsa.uiuc.edu/Cyberia/NumRel/GenRelativity.html">general relativity</a> (since the satellites are farther away from the mass of the earth, clocks appear to run faster as seen from the ground). The net effect of both is that clocks aboard GPS satellites would gain 38 microseconds per day relative to the ground, if relativistic effects were not corrected for--a figure which can be confirmed by using <a href="http://tinyurl.com/5eojo">Google calculator</a>. tag:metafilter.com,2004:site.37363 Tue, 30 Nov 2004 19:33:20 -0800 globalpositioningsystem google googlecalculator gps physics relativity science DevilsAdvocate