On 30 May 2014 04:08, John Ross <[email protected]> wrote: > Thanks for the comments. >
My pleasure . > > > Let me try one more time to explain what I think about time dilation. I > believe that if we try to measure how fast time is passing in a reference > that is moving very fast with respect to our reference frame, we will get a > different answer than someone measuring how fast time is passing in the > fast moving reference frame. > You will indeed. You agree with special relativity on this. > > > What I also believe is that time is absolute and passes at the same speed > everywhere in our Universe. > This is demonstrably untrue, as GPS (amongst other things) shows. > In other words we could measure how much time has passed since the Big > Bang, we would all get the same answer. I read somewhere that the Big Bang > occurred 13.72 billion years ago and that the number was accurate to 4 > decimal places. I understand some galaxies are moving away from us very > fast maybe at speeds close to the speed of light. Would the people in > those galaxies make the same estimate as we do? If so that would indicate > to me that the passage of time is the same everywhere in our Universe. > You're drawing the wrong conclusion. For observers at rest with respect to the "Hubble flow" and in negligible gravitational fields, the time since the Big Bang will come out the same. Other observers will get different results. Brent can explain this, with diagrams if necessary. > > > I also concede that atomic clocks run at different speeds in fast moving > satellites than they do on earth. There may be some explanation for the > discrepancy other than that time is actually passing faster or slower in > the satellites. For example my understanding is that atomic clocks are > based on the frequency of light emitted from certain atomic transitions. > Maybe the frequency changes at very high relative speeds or at different > gravitational forces or different radial acceleration or there could be > other answers. > *Everything* runs at different rates in satellites, not just atomic clocks. This isn't some weird physical effect of atomic clocks or whatever, it's simply a result of observers taking different paths through space-time. > > > In any case, I realize I could be wrong. > > Good, because so far Einstein's defeated all comers. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
