There is none, it is just one assumption of SR theory (SR is a model of a physical system). If the theory leads to testable predictions then we can find out whether the model is good or bad, and we no longer need to spend our time navel-gazing about the assumptions ;)

This seems just not a real question, you only want to promote your paper

When you exceed a certain age you don't need recognition, I don't care at all, I need a physical demonstration to know where I'm going astray....

@trula doesnt matter.It is a valid question.

@TheTiler the physical argument is that it predicts a lot of experimentally observed data

see comment below

I agree the question is valid, but promoting your own theories is in rather bad taste on this forum.

You could also ask: To demonstrate Galilean transformations mathematically, we assume that time is a dimension (via linear transformations, etc.), what physical argument requires us to do this?

@AlbertusMagnus he is not promoting his own theory , the people who believe that are very ill-intended and their opinion shouldnt really matter tbh because they are not educated , they just know stuff.If someone was educated , they wouldnt be so ill-intended. I just simply dont understand how someone can be so selfish and cold.Anyway this should have never been closed down in the first place.

"I just don't understand how someone can be so selfish and cold.", I don't understand anything about behavioral psychology, I formalized a physical idea, you don't agree, show me where I went astray...., and I'm trying to understand where the causes of your judgments are ( prejudge)!!!, if you believe with this that you will change my ideas and my convictions, you need more than the whole world like you...

@TheTiler not you the ones who say ur promoting ur own theory.Even if that was true , to think that way shows a bad quality of character.

@TheTiler if you want to promote your theory,you should contact a professor from a department of physics(or astronomy).People in the Internet could be literally anyone from the shitiest person to the nicest person,so dont take seriously negative reviews.If you think your theory has merit(isnt unvalidated by some source),you should try to reach out a professor of a physics department.

I don't understand this relentlessness against a simple physical question? if you want me to erase it, I will and it's not equations that will make me live.

What would accept as a physical argument to say that distance from the center of the earth is a dimension?

What relation to my question, you think you are more intelligent, show me your abilities, give me a simple answer even verbal !

TheTiler said “see comment below”. There are currently 26 comments below, with more likely

I did what I could to answer (you have to take my answer in context, there weren't many comments).

At TheTiler. That is useless on this site. Here comments are always changing and even the ordering can change. So “see comment below” does not clearly point one to anything. Just copy paste next time. Also, use @<Name> to bring something to someone’s attention

yes, thank you, I will try to be more concise..., I am far from the field but now I will try to pick up my pen again to understand everything that is happening...