---Quote (Originally by adsar)---GPS is viewed as the litmus test.---End Quote---Which I would like to debate but as I was suspended for doing so I have a problem. My argument (against GPS proving time dilation) is not an ATM idea so I wouldn't know where to post it. It's a solution to an engineering problem that has been used throughout the 20th century for many things, and has nothing to do with relativity and it's not required for accurate measurements.That few seem to be able to grasp the first princples of multilateration is the problem I have. Has any member here had any involvement with GPS sofware? They would be able to clear it up easily as the formula for positioning do not use any particular time clock. Any error in one transmission time will always be proportional to the other errors in the other transmission times. All GPS recievers must make this adjustment routinely as they do not have atomic clocks installed. Hence they cannot be accurate to any degree using the time duration of the signal. That is devolved from the multilateration formula which effectively reveals the same proportional error in all the signals. This time duration error is proportionally removed from each satellites time duration as compared to each other, until they agree to distances that point to a single point on the globe. The simple fact is this works irrespective of the actual time sent by the satellite. Any time will do as long as all the transmitted signal sources use the same synchronised time.That the clocks run faster on the satellites may* be an indication of GR but SR must always be an assumption as it is opposite to the effect. The magnitude (of SR) is impossible to know for sure. It could be as predicted or it could be 0.I'm stating GPS neither proves nor disproves either GR or SR, as it doesn't need any adjustments to work because the actual time used by the GPS system is irrelevant. Only synchronised time between them is important and that's broadcast continually from control stations, overiding any clock rates amendments set pre launch.*I say "may" because GPS time is broadcast to the satellites on a continual basis to counteract clock drift error, so at this point any time dilation cannot be known for sure. It's quite possible that the original clock used to determine the effect was as bad as the clocks used by H&K. As I posted previously, they couldn't get them consistent to the correct sign, let alone determine anything from the magnitude.