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   sci.physics.research      Current physics research. (Moderated)      17,516 messages   

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   Message 16,282 of 17,516   
   Ed Lake to mr...@ing.puc.cl   
   Re: Simplifying Einstein's Thought Exper   
   15 Jul 18 22:30:38   
   
   From: detect@newsguy.com   
      
   On Saturday, July 14, 2018 at 11:40:18 AM UTC-5, mr...@ing.puc.cl wrote:   
   > El s=C3=A1bado, 14 de julio de 2018, 11:17:42 (UTC-5), Ed Lake    
   escribi=C3=B3:   
   > > On Friday, July 13, 2018 at 4:45:15 PM UTC-5, mr...@ing.puc.cl wrote:   
   > >> El viernes, 13 de julio de 2018, 0:33:23 (UTC-5), Ed Lake  escribi=C3=B3:   
   > >>> On Wednesday, July 11, 2018 at 8:31:48 PM UTC-5, Ed Lake wrote:   
   > >>>> On Tuesday, July 10, 2018 at 12:56:03 PM UTC-5, Edward Prochak wrote:   
   > >>>>> On Monday, July 9, 2018 at 3:11:05 PM UTC-4, Ed Lake wrote:   
   > >>>>>> [Moderator's note:  Huge amount of quoted text deleted.  Please quote   
   > >>>>>> only enough to provide sufficient context.  -P.H.]   
   > >>>   
   > >>> < snip >   
   > >>>   
   > >>>> [[Mod. note -- As Tom Roberts (& others) have pointed out, in order   
   > >>>> to directly compare clocks A and B, A and B must be colocated for   
   > >>>> the duration of the comparison, i.e., they must be at the same   
   > >>>> position and (be observed by *all* observers to be) moving at the   
   > >>>> same velocity.   
   > >   
   > >>> How can you compare a moving clock (B) to a "stationary" clock (A)   
   > >>> if "A and B must be colocated for the duration of the comparison"?   
   > >>>   
   > >>   
   > >> The moving clock is assumed to be moving at a very high speed (in order to   
   > >> time dilation effects to be observed). So if clock A is moving at speed   
   0.6c   
   > >> in order to measure the time dilation you need a set of Einstein   
   synchronized   
   > >> clocks located along the path clock A is following.   
   > >>   
   > >> This is the only way to check the readings of clock A with the readings   
   of the   
   > >> synchronized clocks, so the clock A reading is directly compared with a   
   given   
   > >> synchronized clock B, as clock A passes through clock B location (at that   
   > >> instant both clocks are colocated).   
   > >>   
   > >> Afterwards, the lectures of the synchronized clocks can be compared to   
   determine   
   > >> the time dilation of clock A. The following diagram shows the setup.   
   > >>   
   > >> Clock A   
   > >>   
   > >> (*) --> v=0.6c   
   > >>   
   > >> (B1)....(B2)....(B3)....(B4)....(B5)....(B6)   
   > >>   
   > >> Synchronized clocks   
   > >   
   > > Sorry, but your beliefs conflict with reality.  In 1971, Joseph Hafele   
   > > and Richard Keating performed a test where they flew 4 atomic clocks   
   > > around the world twice, first flying them eastward, then westward.   
   > > Before each trip they compared the clocks to a master atomic clock at   
   > > the US Naval observatory.   
   > >   
   >   
   > Firstly, these are not my beliefs but facts of the SR model. Secondly, your   
   > description of what Hafele and Keating did is correct.   
   > But you have to understand that the comparison among clocks were performed   
   > AFTER the experiment. The atomic clocks were flown around the world, as you   
   say   
   > but, obviously, they could not compare their clock readings with the readings   
   > of the master atomic clock while they were flying (since the clocks were not   
   > colocated).   
   >   
   > And finally, what the comparison was about related to the ELAPSED time of the   
   > different clocks. The elapsed time of a clock is not the tick rate of that   
   clock.   
      
   If the clocks tick at the same rate and show the same time at the   
   start of the experiment but showed different elapsed times after   
   the experiment, then the difference in elapsed times indicates a   
   difference in tick rates.  If the clock that moved shows an elapsed   
   time that is 24 nanoseconds less than the "stationary" clock after   
   24 hours, then the clock that moved ticked at a rate that was 1   
   nanosecond per hour slower than the clock that was stationary.   
      
   Ed   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)   

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