🚀 go-pugleaf

Subject: Re: Orthodox special relativity

In <1992Aug5.062852.5646@sbcs.sunysb.edu> rscott@csws4.ic.sunysb.edu (Robert 
Scott) quotes me 

>> In article <BsBI3x.5F1@wpi.WPI.EDU> phillies@wpi.WPI.EDU (George D. Phillies)
>>writes:

many omitted words

and claims

>THIS IS VERY MISLEADING.  THE FACT IS THAT THE EFFECTS OF SPECIAL RELATIVITY
>(ESPECIALLY THE AMBIGUITY OF SIMULTANEITY FOR OBSERVERS MOVING AT DIFFERENT
>VELOCITIES) ARE CAUSED IN A SIMPLE AND DIRECT WAY BY SPEED-OF-LIGHT DELAYS.

No, this is **orthodox** special relativity.

>PHILLIES SEEMS TO BELIEVE THAT SPEED-OF-LIGHT DELAYS ARE UNIMPORTANT BECAUSE
>YOU CAN ALWAYS JUST CORRECT FOR THEM.  THE PROBLEM WITH THIS IS THAT THE
>ALGORITHM FOR CORRECTING FOR SPEED-OF-LIGHT DELAYS IS CRUCIALLY DEPENDENT ON
>THE VELOCITY THAT YOU BELIEVE YOU ARE TRAVELING AT.  

"Travelling at" with respect to what?  

>IF YOU ARE STANDING STILL THEN YOU SHOULD FIGURE THAT YOUR RADAR PULSES HIT 
>THEIR TARGETS EXACTLY HALF-WAY IN TIME BETWEEN SENDING THEM AND RECEIVING THEM 
>BACK, WHEREAS IF YOU YOURSELF ARE MOVING THEN YOU HAVE TO FIGURE THE DIFFERENCE 
>IN DURATION BETWEEN THE FORWARD AND RETURN TRIPS.  

A Galilean object moving through an ether has serious problems with
Michaelson Morley experiments.  It is possible to cook up theories which appear 
to explain one-dimensional experiments in terms of contractions and clock
slowing-downs.  In my experience, these theories tend to run into problems when 
asked to explain why two boosts in non-parallel directions should be
equivalent to a single boost plus a rotation, as is observed experimentally.

It may be possible to cook up a set of physical properties for a luminiferous 
ether and its effect on matter and on clocks that will cause it to predict 
exactly the same behavior as the Lorentz transformations, i. e. the same math 
theory, including the effect of motion on displaced clocks, but two different 
sets of words to describe the same math.  I can't see an easy way to construct 
a legitimate proof that this is impossible.  However, there is an orthodox 
interpretation of how relativity works, which is what I am presenting.  

>AS A RESULT, THERE IS NO 
>VALID ALGORITHM FOR CORRECTING FOR SPEED-OF-LIGHT DELAYS WITHOUT KNOWING YOUR 
>OWN VELOCITY RELATIVE TO SOME MASTER INERTIAL FRAME, 

So you say.  The usual solution involves a series of spatially displaced 
observers, all stationary with regard to their fellows, so that the comparison 
with the moving frame is performed by a stationary observer for whom the speed 
of light delay is zero.

>AND OBSERVERS MOVING AT 
>DIFFERENT VELOCITIES, EACH CONVINCED THAT THEY ARE THE ONE STANDING STILL, ARE 
>UNABLE TO AGREE ON THE MEANING OF SIMULTANEITY, EVEN AFTER THEY HAVE TRIED TO 
>CORRECT FOR SPEED-OF-LIGHT DELAYS.  

Gee, we agree. Trains of relatively moving observers cannot agree on 
the sets of space-time points that involve simultaneity.

>THAT'S ALL THERE IS TO IT:  (omitted hint)  GIVEN THIS HINT, ANY BRIGHT FIFTH-
>GRADER CAN WORK OUT THE KINEMATICS OF SPECIAL RELATIVITY ALL BY THEMSELF.  
                                                                 ^HIM OR HER

I am short of bright fifth graders here.  Would you care to post what your 
fifth graders did on this question?

>THE KINEMATICS OF SPECIAL RELATIVITY IS SIMPLE COMMON SENSE ...

Scientific reasoners who invoke common sense are wisely treated like
politicians invoking patriotism: count the spoons, and keep one hand
on your wallet.  It is not intrinsically bad, but it is a tad bit
suspicious.

>... ARBITERS OF ORTHODOXY MIGHT STAND A LITTLE "THOUGHT CLARIFICATION"
>THEMSELVES.

The alternative model not seen here may be indistinguishable in all 
consequences from orthodox special relativity.  It may even be correct (how 
does one tell?)  But it is not orthodox.

George Phillies                   "Teaching the general idea is
Professor of Physics               the enemy of good teaching."
phillies@wpi.wpi.edu