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I know this has been asked before but I would like to float a related question.

Why does the second postulate specifically refer to

This is the wording that I am referring to:

Two answers I have seen are:

1. The second postulate follows directly from the application of the first postulate to electromagnetism (in which case it seems you really only need the first postulate). The invariance of c is a consequence of this.

and

2. "If you are looking for proof, then I am afraid you will be disappointed. Postulates can not be proven, they are assumptions or statements made." (from https://www.physicsforums.com/showpost.php?p=1140259&postcount=2")

Another answer can be is that a more rigorous wording would be "light is always propagated in empty space with an invariant velocity which is independent of the state of motion of the emitting body".

The issue I have is not that the speed of light is invariant, but that it seems there are people who stop all further debate as to why the speed of light is invariant and why it is the particular speed it is (ie

So, what

For a possible answer we could look at natural units. As discussed http://en.wikipedia.org/wiki/Planck_length" [Broken]:

This indicates that Planck units have

I wonder if it is possible to consider that there is a link between these measurements, at which scale time and space become discrete, "foamy" or as I prefer "granular", and the speed limitation placed on photons.

For example, if the smallest measurable time duration is one Planck time and the smallest measurable length is one Planck length and these measurement limitations are physical, rather than being limitations associated with our measuring regimes, then we are left with a limitation where a discrete particle (or wavicle) can either move one discrete length in one discrete time duration at speed

Now the actual location of individual quarks can't be pinned down, we can only assign each possible location a probability (and this is a physical thing again, not a limitation on our measuring devices). Get enough quarks together, enough to constitute a mass as we know it, and you have a probability cloud. The centre of the mass is somewhere in that probability cloud and if you look at it from a macro perspective, you can now point at where the mass "is", with the tacit understanding that this is an approximation. A mass which consists of a large number of discrete particles/wavicles, each of which is restricted to a speed of

Is this at all valid?

Is it valid to think that the light speed limitation of the second postulate is due to quantum level foaminess?

cheers,

neopolitan

Why does the second postulate specifically refer to

*c*?This is the wording that I am referring to:

that light is always propagated in empty space with a definite velocitycwhich is independent of the state of motion of the emitting body

Two answers I have seen are:

1. The second postulate follows directly from the application of the first postulate to electromagnetism (in which case it seems you really only need the first postulate). The invariance of c is a consequence of this.

and

2. "If you are looking for proof, then I am afraid you will be disappointed. Postulates can not be proven, they are assumptions or statements made." (from https://www.physicsforums.com/showpost.php?p=1140259&postcount=2")

Another answer can be is that a more rigorous wording would be "light is always propagated in empty space with an invariant velocity which is independent of the state of motion of the emitting body".

The issue I have is not that the speed of light is invariant, but that it seems there are people who stop all further debate as to why the speed of light is invariant and why it is the particular speed it is (ie

*c*) with answer 2 above.So, what

*c*in particular? And why does the speed of light in a vacuum have the value it has?For a possible answer we could look at natural units. As discussed http://en.wikipedia.org/wiki/Planck_length" [Broken]:

it is impossible to measure position to a precision shorter than the Planck length, or duration to a precision to a shorter time interval than a Planck time.

This indicates that Planck units have

__some__physical meaning. They are also interesting because Planck length/Planck time =*c*.I wonder if it is possible to consider that there is a link between these measurements, at which scale time and space become discrete, "foamy" or as I prefer "granular", and the speed limitation placed on photons.

For example, if the smallest measurable time duration is one Planck time and the smallest measurable length is one Planck length and these measurement limitations are physical, rather than being limitations associated with our measuring regimes, then we are left with a limitation where a discrete particle (or wavicle) can either move one discrete length in one discrete time duration at speed

*c*, or stay motionless. This would make*c*not only the maximum speed, but also the**minimum**speed - for discrete particles, ie quarks.Now the actual location of individual quarks can't be pinned down, we can only assign each possible location a probability (and this is a physical thing again, not a limitation on our measuring devices). Get enough quarks together, enough to constitute a mass as we know it, and you have a probability cloud. The centre of the mass is somewhere in that probability cloud and if you look at it from a macro perspective, you can now point at where the mass "is", with the tacit understanding that this is an approximation. A mass which consists of a large number of discrete particles/wavicles, each of which is restricted to a speed of

*c*but not restricted in direction, could in fact travel, as a statistical average, slower than*c*- even if each individual discrete particle/wavicle travels**at***c*. In fact, the more of them you have, the more difficult it will be to get them to all travel in the same direction, and more energy will need to be applied to get them to travel in pretty much the same direction.Is this at all valid?

Is it valid to think that the light speed limitation of the second postulate is due to quantum level foaminess?

cheers,

neopolitan

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