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Talk:Counterexamples to Relativity (view source)
Revision as of 19:04, August 9, 2010
, 19:04, August 9, 2010→Misleading Reference: new section
:Simeon: Ah, that does make a lot of sense now. Thanks so much for explaining this to me. Hmm, that really is an elegant concept -- wow. Cool! [[User:PhyllisS|PhyllisS]] 13:50, 5 August 2010 (EDT)
:Simeon: Ah, that does make a lot of sense now. Thanks so much for explaining this to me. Hmm, that really is an elegant concept -- wow. Cool! [[User:PhyllisS|PhyllisS]] 13:50, 5 August 2010 (EDT)
== Misleading Reference ==
The counterexample #18 has as an reference:
''Contrary to the claims of Relativists, the GPS system has never been based on Relativity. The Time Service Department, U.S. Navy, observed that "the Global Positioning System (GPS) does not include the rigorous transformations between coordinate systems that Einstein’s general theory of relativity would seem to require" in part because "the effects of relativity, where they are different from the effects predicted by classical mechanics and electromagnetic theory, are too small to matter – less than one centimeter, for users on or near the earth.”''
That's wrong: From the very beginning of the program, some relativistic effects were taken into account. As Conservapedia states at its article on [[GPS]] the Naval Research Lab in Washington published its report on the ''Initial Results of the NAVSTAR GPS NTS-2 Satellite'' in 1978 and listed the following GPS objectives that have been achieved to date:
#launch insertion into GPS constellation position
#demonstrated orbit stability and controllability
#first cesium frequency standard in space
#'''verification of relativity theory'''
But not only did the initial experiments bolster the theory, some relativistic effects have to addressed in general use - in the official specification for the GPS project , i.e., the [http://www.navcen.uscg.gov/pubs/gps/sigspec/gpssps1.pdf Global Positioning System Standard Positioning Service Signal Specification], 2nd edition, June 1995, you find the following:
p. 13: ''To compensate for relativistic effects, the output frequency of the satellite's frequency standard -- as it would appear to an observer located at the satellite -- is 10.23 MHz offset by a Df/f = -4.4647 x 10-18 or a Df = -4.567 x 10-3 Hz.''
p. 39: ''The coefficients transmitted in subframe 1 describe the offset apparent to the control segment two-frequency receivers for the interval of time in which the parameters are transmitted. This estimated correction accounts for the deterministic satellite clock error characteristics of bias, drift and aging, as well as for the satellite implementation characteristics of group delay bias and mean differential group delay. Since these coefficients do not include corrections for relativistic effects, the user's equipment must determine the requisite relativistic correction. Accordingly, the offset given below includes a term to perform this function.''
It's true that not '''all''' effects are covered yet: as [[Talk:Counterexamples_to_Relativity#GPS_revisited|I stated above]], the quoted article of the ''The Time Service Department, U.S. Navy'' addresses effects caused by the fast movement of some of the GPS-receivers - something which will doubtless be included as the number of fast receivers grows.
[[User:RonLar|RonLar]] 15:03, 9 August 2010 (EDT)