Originally Posted by

**Nazaroo**
One previous poster had some insight into the flaw in the 'thought experiment'.

Although badly worded, the basic point is this:

(1)** Either you allow the clocks to 'tick' independantly, or else you tie them to the earth's orbit, correcting them when they stray.** You can't have it both ways. If they tick freely, without correction, then both clocks will eventually be out of sync with the sunrise, and also each other.

This has little to do with testing 'time dilation', and everything to do with composing an experiment with a clear coherent purpose and method.

(2) **The poor timekeeping qualities of the clocks will have no discernable effect on the delivery of your newspaper, that I can see.** The newspapers that must be delivered will arrive early or late according to the method of transport and distance, and will have dates reflecting the way newspapers keep time, not based how either clock keeps time.

This has little to do with 'time dilation', and everything to do with how newspaper publishers use the earth's orbit (suitably adjusted by leapyears) to keep time.

(3) The most accurate measure of time/distance that we have are by the use of light signals carried by light quanta (quantized packets of energy), which have no mass and a 'fixed' speed or rather a **calibration speed** expressed in distance/time units (186,000 mps).

As Einstein would say, echoing his mentor Mach, times and distances and speeds are all measured RELATIVELY. That is, we can't speak of 'absolute speed'. All motion is measured relative to other objects in space. We measure motion using LIGHT as the final calibrating arbiter, because according to Special Relativity, Light behaves predictably as per the equations of Special relativity, which describe and 'predict' the expected numbers.

In Classical Newtonian Theory, all velocities are expressed RELATIVE to an 'inertial frame', which for practical purposes, we assume is not accelerating relative to Newtonian Absolute Space. This results in the famous F = mA type equations of motion, which work well at low "velocities".

When we do this at high speeds (e.g. light-speeds), we find that light and all other moving particles obey the Laws of Motion described by **Special Relativity**, and so we modify our description and understanding to give something like a "Special Relativity Space/Time".

This also is not a 'true' description of space/time, but rather a convenient approximation to "local" space/time behaviour, regarding the equations of motion.

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In the above discussion, please notice two very strange 'limitations':

(1) **"low velocities"** which mathematically imply some kind of 'absolute' scale of velocity independant of relative measurement of velocity (once suitable units of measurement are chosen), because these units are 'arbitrary' but the absolute "pure" numbers are NOT.

To explain the mathematical problem further, we can say that although numbers are arbitrary and abstract, the ALGEBRAS they represent are NOT. We can clearly distinguish the difference in behaviour between a number between 0 and 1, and a number greater than 1 for instance.

Or we can distinguish between 'operators' such as multiplication and division, because although we say the 'order of operations' of these two are equal, they are in fact NOT.

a x b = b x a, but a/b is not = b/a.

These are analogies, but the point is that certain numbers in the universe are NOT arbitrary in the sense that we can put 'anything' in there. Similarly, the various constants (Plank's constant,the Gravitational Constant etc.) appear to have a Platonic reality beyond the arbitrary selection of a 'number' to represent them.

Other 'constants' are just secondary phenomenae that reflect a choice of units or a relationship, but not a real 'constant'.

How can one speak of "low velocities" in the discussion of Special Relativity, which tries to presume that all motion is relative, and that there are no real 'inertial frames' at all? (I speak now of the theoretical underpinnings and discussion surrounding the historical acceptance of the theory, such as the exchange between Einstein and Mach).

There is a real philsophical and physical dilemma posed here. The actual numbers for Special Relativity (SR) are not arbitrary.

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(2) **"Local Spacetimes"** again pose a strange 'sizing' problem. We say in General Relativity (GR) that "locally" spacetime conforms to "special relativity", but in the 'big picture' we have to fit all these local spacetimes together in a rather more complex manner than simply stacking them like 'Lego blocks'.

At a larger 'sizing', we connect all these local spacetimes via the adjustments caused by the 'warping of spacetime' by the presence of MASS. This allows for larger-scale 'bending' of spacetime over distances that dwarf the local measurement of spacetime that seems to reflect SR.

How small is "local", and how big is "larger, (GR - style) spacetime"? This also is not an arbitrary 'sizing' dictated by choice of units, but a real physical entity, a 'constant' of some kind, that is intimately tied to the 'size' of atoms and molecules and their density.

Both of these factors (quite without quantum considerations) hint at a kind of 'Absoluteness' of Spacetime that Newton himself would have recognized as supporting Newtonian 'absolute space' far better than Machian 'absolutely relative motion'.

Although Einstein attempted to 'prove' Mach's program of a purely 'relative' physics, he ended up creating a new "absolute spacetime monster", General Relativity, which postulates a 'gravitational field' as real as Newton's "absolute space" and a perhaps more accurate one.