That is correct. They are equivalent. There is no absolute frame of reference. The only thing that is fixed is the speed of light. Time and distance are variables.
Yes: but some reference frames make setting up and solving the equations of motion *much* simpler than others.
Cheers!
Said grey_whiskers:--This part of the post explicitly said, that the coordinate system was chosen for ease of use, not because one was "true" and the other "false".Replied LeGrande:That is correct. They are equivalent. There is no absolute frame of reference. The only thing that is fixed is the speed of light. Time and distance are variables.
No one ever said that the CS of geocentrism and geokineticism were shown to be either true or false. What is being said is that they are equivalent and there is no observational or physical way of distinguishing between them. The fact is that it could equally mean that the earth is not moving.
Also, saying there is 'no absolute frame of reference' is an assumption of GR not a demonstrated fact. And, GR does not require that the speed of light be fixed across time, only that it be the same throughout the entire universe at any point in time. That is a huge difference in meaning. If the speed of light is not fixed across time, then time and distance are not variables.
If you performed an experiment to detect the assumed motion of the earth about the sun, found no sign of said motion and then developed a theory that assumed that motion but had to be consistent with no evidence for it, you would have GR.
And again, let's not assume that ease of use represents reality because then you would have one reality within the earth-moon system and an opposite reality within the solar-system. That you choose to believe the solar-system CS is a philosophical choice, nothing more. That's what Ellis was saying.
What you guys fail to understand is that a huge number of things you accept as fact, are not.