Imatfaal,

About the quote you refer to from JP;- My response to that is - "Yes there is a definite reason why time dilation is more important than length contraction." In fact, I would go so far as to say that time dilation is important but length contraction is not. (provocative right?);-

When Hafele & Keating proved in 1971 that time dilation could be measured in accordance with Special Relativity, they actually proved it is REAL! Sadly, even today, this has still not sunk in for the mainstream! Although we all understand that you cannot detect any change in time rate from within your own frame, the RELATIVE differential time rates between moving frames is nevertherless a reality. Length contraction, on the other hand, is NOT real. It is merely a relative ILLUSION. How can I say this? Well, when the clock in the moving frame stops moving, it bears the evidence of the time rate differential during the journey and we can predict this and prove it by experiment. The length contraction demonstrates no such evidence on return to the stationary frame and as far as the stationary frame's experience goes, it does not experience any effect whatsoever from the movement of light or objects relative to it.

If we consider two close, moving plates with a relative electric charge then it does not matter which argument you use to calculate the relative compression of the electric field. Both Lorentz velocity increase and length contraction give the same result. So we can say any and all relative effects between frames can be viewed as a result of either. There is no scientific compelling argument to choose length contraction, more the discomfort of exceeding "c" in the moving frame if we choose velocity increase.

You can refer me to as much math as you like, but I, and you, as well as others in this forum, have a brain which is superior in certain ways to the best of mathematics. Here's a great quote;-

"Mathematics and physics take fundamentally different approaches to describing nature. The former is more concerned with what might be possible, and the latter with what is definitely real. Math is constrained by the need for internal consistency, but is generally oblivious to external constraints. Physics has its laws too, and these can change as knowledge improves. But physics is rigorously constrained by its principles which have no counterparts in mathematics. Examples are, the causality principle (“Every effect must have a proximate antecedent cause”), and the prohibition against creation. Violations of such principles are ruled out by logic as requiring magic, a miracle, or the supernatural. Although mathematically allowed, they are said to be physically impossible."

Tom Van Flandern & J. P. Vigier

(Foundations of Physics (32:1031-1068, 2002)

Now I am not anti math, far from it, but the mathematicians have "taken over" physics in the last hundred years and we are left with certain mistaken beliefs as a result. In the case of SR, it is unfortunate that we can justify, mathematically, our mistaken beliefs, but we can also justify the reality using the same mathematical rules. At the moment, the mainstream refuses to listen to the alternative and whenever it is tabled, obstacles are placed in the way of the argument before the case can be properly made. Our ducks are shot down before the row forms.

You will no doubt feel yourself wanting to do just that. It is human nature to resist any change in our beliefs.

If we come to terms with time dilation being THE reality (try to believe this for the moment), then we must accept, for reasons of causality, that TIME is the cause of ALL effects within space-time. There is nothing else available to affect anything. I am saying the distortion of a vacuum is unreal and that GR is a great way of getting to the right answers but it does not reflect reality. The abstract idea of breaking down volume into a Gaussian geometric frame, works in the mathematical sense, but you cannot attribute the property of variation to what is essentially, NOTHING !

If all this is the case, then when the time rate changes, only time related events or effects will likewise become affected as a result. Spacial or physical entities, (scalar quantities), cannot be affected by the time dilation of motion.

This means that velocity MUST change if the time rate changes since velocity has a time attribute (m/s, km/hr). It is a time related occurence and if you change the value of the unit of time then you change the value of the velocity.

If the velocity changes, then the length CANNOT change since Lorentz allows EITHER velocity OR length to change but NOT both.

You can do the math with Lorentz. It is very simple, and "c" turns out to be infinite in the moving frame whilst maintaining the limit of "c" as observed from the "stationary" frame.

As, v_{s}→c

Then, v_{m}→∞

It is this relative limit that has deceived us for over a century since we never observe anything faster. We would have to accelerate to some significant fraction of "c" to look out of our porthole and see the universe BLUE SHIFTED and speeding by with increasing velocity tending toward ∞ as we approach relative "c". Yes I know the SR argument of V being purely relative, but the symmetry of space simply does not apply to the dimension of time. Time is uni directional or assymetrical and any geometric analysis of space-time can become confused by ignoring this difference in nature between space and time.

So where does all this get us in answering your comment?

Well, all you have done is to throw the mainstream arguments at me and I am not dissagreeing with anything you suggest since we get the right answers from any analysis using them. If I may, I must throw my alternative arguments back at you which will give the same results. The question then simply boils down to deciding which version best reflects reality.

The speed of light is a constant outside of a gravitational potential. Agreed, except that I contend it is infinite when observations are made from the frame of the light beam, since its clock has stopped relative to the rest of the universe.

In a gravitational field, it would still be observed as a constant "c", if the observer's clock tracked the light beam's clock as it moved through the field. But since, in reality, we cannot do this and our clock remains constant whilst the beam's clock varies depending on its elevation in the field, we therefore observe a variation in speed. Agreed, except it is still infinite as observed from all the frames of the beam during its travels.

I am surprised you did not mention the doubled Newtonian deflection of the beam. Einstein attributed this to "One part due to the Newtonian free fall and one part due to the geometrical variations in space."

Here are extracts from a paper which gives the real reasons;-

“……………………..If we take into account the wave nature of light, there is an additional contribution coming from the time dilation in relativity. The observation that this contribution is independent and additional to the Newtonian deflection of the mean trajectory is the main purpose of this paper.

……………One does not need full general relativity for deriving the expression for the deflection of light. What is needed are the equivalence principle, conservation of energy, and the wave nature of light. One part of the deflection comes from the free fall of the particle or light ray in the gravitational field, and the deflection depends on the average velocity of the test particle. The other part comes from the red shift factor. This is always given by, 2GM/c^{2}r

independent of the velocity………

………………..For light, both contributions have the same magnitude, and they add to give the full deflection;- 4GM/c^{2}r ”

On the gravitational deflection of light and particles

C. S. Unnikrishnan

Current science, vol. 88 No. 7, 10 April 2005

I take this one step further and state;-

The doubled deflection of the beam is due to One part Newtonian and One part wave front bending, BOTH due to local time dilation.

Einstein's notions of the distortion of volume and the geodesic, although essential in predicting outcomes, nevertheless divert us from reality. The reality is the time rate field, and anything that is demonstrated by GR can be equally demonstrated by an analysis of temporal effects.

There's much more, of course.