🚀 go-pugleaf

"Phil" <toob-headman@sbcglobal.net> wrote in message news:LIGFh.576$uo3.82@newssvr14.news.prodigy.net...
> Edward Green wrote:
> 
>> Wolfgang G. Gasser wrote:
>> 
>> 
>>>Two distant observers with each a (transversal) LIGHT CLOCK orbit at a
>>>constant distance around their common center (assumed at rest).
>>>
>>>Special relativity postulates that the light beams in both light clocks
>>>propagate at c relative to both (almost inertially moving) observers.
>> 
>> 
>> This needs to be reworded, I think.
>> 
>> 
>>>This requires that for each observer the clock rate of the opposite clock
>>>CAN be lower than the clock rate of his own clock.
>>>
>>>Because of symmetry and unchanging distance, clock rate CANNOT differ.
>>>
>>>The impossibility of mutual time dilation in this situation entails the
>>>impossibility of a constant speed of light as a general law.
>> 
>> 
>> Of course you haven't "disproven special relativity", but I think it's
>> a good conundrum.  I'm not really happy with "non-inertial observers"
>> as the full rebuttal.  That's the answer at the old transatlantic cable
>> rates -- words are now cheaper.
> 
> I like your answer best. I looked at situations like this one a lot a 
> few years ago, including one where a spaceship orbits the Earth, and 
> sees time passing faster, not slower, for the Earth, even though 
> acceleration has been proven to have no relativistic effects whatsoever. 
> It turns out that yes, things like this can happen, but they don't 
> violate the laws of SP. Two INERTIAL observers will always see each 
> other as having a slower time-rate (well, as long as they don't travel 
> around the universe), and that is indeed the prediction of SP, but under 
> SP, non-inertial observers will not see the same thing.
> 
> However, although people often claim that we need GR to solve such 
> problems, GR is only necessary if large gravitational fields are 
> involved. As long as only acceleration is invovled, including large 
> acceleration, we can use the laws of SR to correctly predict the 
> results. 

Newtonian Mechanics is easier and more accurate, you don't need
that stupid 1/(sqrt(1-v^2/c^2).


> In fact, using GR's technique of replacing an acceleration with 
> an equivalent gravitational field will only work if the acceleration is 
> constant. 

Never trust a sentence starting with "In fact", "Actually", "Obviously"
or similar assertions, it's a sure thing what follows is going to be utter 
bullshit.  

The advance of perihelion of Mercury is entirely predicted
by Newtonian Mechanics to within 43 arc seconds per century 
(=  415 orbits) which is

415 orbits * 360 degrees = 149400 degrees
149400 degrees * 60 arc minutes = 8964000 arc minutes
8964000 arc minutes * 60 arc seconds = 537840000 arc seconds.


                  43
--------------------------------  x 100 = 0.00000799494273389855719%
            537840000


and Einstein with his 4-figure log tables and 3-figure sliderule
could not be that accurate. Obviously. In fact. Actually.


> Varying acceleration, such as found in the normal clock 
> paradox, cannot be solved using this "GR substitution," as Wolfgang 
> Rindler pointed out in his book, "Special Relativity" a long time ago.
> 
> Phil
> 
>> 
>> Obviously the situation is fully symmetric, but then, so is the
>> situation of inertial observers passing each other at constant
>> velocity: why bother with the rotation, when we could already argue
>> that "each clock is running slower with respect to the other, which is
>> obviously impossible".  That's already a fairly piquant paradox, which
>> I have no ready glib answer to, and one of the special charms of SR!
>> 
>> Roughly, the dependence of t and t' on x' and x, respectively, is what
>> enables the math to weasel out of this seeming contradiction; also,
>> "running slower with respect to the other" may not be operationally
>> well characterized.  Ask any concrete empirical question, and we get a
>> single answer -- if we accept the implied operational characterization
>> of "running slower with respect to the other", then we have extended
>> the sense of the phrase in a new situation to exclude one of its
>> expected properties (non-reflexivity).
>> 
>> Standard concept-splitting.
>> 
>> The "non-inertial observer" thing seems cheap to me, and possibly off
>> the mark.  Rotating rings force SR to show its cards by allowing
>> movement in a closed path, but acceleration is not necessarily crucial:
>> it can be made as small as we like for fixed speed of the circumferance
>> by choosing a large enough ring.  Both clocks are running slow as
>> according to an inertial observer at the hub.  How do they describe
>> each others behavior?  They had better be careful to make some
>> empirical predictions!  Then they will agree.  Distrust glib language.
>>