On 24 June 2014 08:55, John Ross <[email protected]> wrote: > All of the GPS satellites know exactly where they are relative to some > position here on earth. They are all in communication with each other and > they know how fast a radio beam travels. It would be a simple matter to > regularly adjust their clock speeds so all of the clocks operate at the > same speed as a master clock here on earth. My guess is that is exactly > what they do. I doubt if it is possible to construct a clock that keeps > time infinitely correctly. >
So what? > > > I think you have said before that if two theories explain the same thing, > it is more likely than not that the simplest theory is correct. I see no > reason why time should pass more slowly if we go fast or quicker if we are > in a reduced gravity. > So far I only know of one (relatively simple :-) theory that explains these observations. > > > Here is a question for you: We on a distance galaxy are watching a > separate galaxy one light-year from a Monster Black Hole and speeding > toward it at a speed of c. A baby has just been born in the speeding > galaxy. How old will the baby be when the galaxy is consumed by the > Monster Black Hole? Our galaxy is stationary with respect to the Monster > Black Hole. My answer is the simple answer. > What is your answer? > > > JR > > > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *LizR > *Sent:* Tuesday, June 17, 2014 3:21 PM > > *To:* [email protected] > *Subject:* Re: TRONNIES - SPACE > > > > On 18 June 2014 08:43, <[email protected]> wrote: > > I understand clocks in satellites do not run at the same speed as clocks > here on earth. However, I just can't understand why we would use > Einstein's equations to adjust the clocks on satellites when it would be > so easy to adjust them in accordance to the exact time here on earth. > > > > That isn't the point. For all I know they may adjust them using clocks on > Earth. The point is that the satellites provide yet another way to test > special and general relativity, and since scientists are always trying to > check their theories are correct, they consider it worthwhile to work out > how fast or slow these theories say the satellites' clocks will run and > compare this to the measured values. The results are in accordance with > both theories - working out the time dilation due to the satellites' > relative motion and their position in the Earth's gravity field gives the > observed result. > > Note that SR and GR give this result without needing any free parameters > to be tweaked. SR involves simple geometry applied to 4 dimensional > space-time; as far as I know the only "free" parameter is the speed of > light. GR involves the gravitational constant (I think) but I'm told there > are no simple ways in which the equations can be modified to give similar > results. Hence the clock rate is "forced" to have a particular value in > both theories - the result falls out naturally from the theories without > any need to introduce any corrections that could equally well have given > other results. > > Here <http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html> > is a more detailed description of this effect. > > > > If you have a theory that can give the same result (with a similar lack of > "wriggle room" for adjusting free parameters) then you should get some > serious interest from scientists. > > -- > 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. > > -- > 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. > -- 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.
