I Does the Light's One/Two-Way Speed Distinction Mean Anything?

[Pony]

There is a trivial metaphysical freedom, that emerges from the fact that people living in a world must use their own measuring devices, that are part of that world.

E.g. people living in a flatland must use their own rulers to measure distance. If one half of their world is widened, they won't notice it if they go there, because they themselves and their rulers will widen too.
( In other words, there is a "true" physics and reality, and there is what they measure and these two differ. Also the former is not measurable, or affect their life in any way. Also the flatland people can choose to believe that half of their world is bigger but unmeasurable, if they want to. )

Now my question. Wiki says that

Albert Einstein chose a synchronization convention (see Einstein synchronization) that made the one-way speed equal to the two-way speed. The constancy of the one-way speed in any given inertial frame is the basis of his special theory of relativity, although all experimentally verifiable predictions of this theory do not depend on that convention.[1][2]

https://en.wikipedia.org/wiki/One-way_speed_of_light
Is the ability to choose synchronizations is a relevant and interesting fact, or it is the same of the rather trivial metaphysical argument, that I wrote about above?

 

[anorlunda]

I recommend this video before asking that question.

 

[FactChecker]

If I understand what you are asking, one answer is this: It all seems academic and only for nerds until someone follows the theory through to develop a nuclear weapon.

 

[Ibix]

Is the ability to choose synchronizations is a relevant and interesting fact,

Being able to choose clock synchronisation is one aspect of the fact that you are free to choose coordinates. If you were not free to choose coordinates you would have to provide some explanation of why your choice of "plane of constant time" was not a free choice, or abandon (or never develop, more likely) spacetime as a model of reality.

 

[Orodruin]

Also the former is not measurable, or affect their life in any way.

If it is not falsifiable, then it is not physics. However, this is not what is going on with the one-way speed of light. The one-way speed of light can be defined to be equal to the two-way speed and isotropic. This is not saying anything about a physical reality. It is just a conventient choice of coordinates. You could have chosen a different way to assign coordinates and the result would be the same. It is just a more convenient way of assigning the coordinates.

Similarly, you can choose to describe a rectangle with polar coordinates. It is an inconvenient choice though and Cartesian coordinates would probably have been better suited. Using polar coordinates would however not change the physical properties of the rectangle, just be a different way to describe the same thing.

If one half of their world is widened

As defined how? If it is not measurable it is not part of the physical reality of flatland. If you need to postulate that something is unmeasurable, then it has nothing to do with physics.

 

[Dale]

Is the ability to choose synchronizations is a relevant and interesting fact, or it is the same of the rather trivial metaphysical argument, that I wrote about above?

I would say neither. It is a convention. Neither particularly relevant nor is it a true or false physics. It is simply a convention like the proton’s charge being positive.