Time: is time a concept or a physical force and can we prove the arrow of time : viewtopic.php?p=317899#p317899
and, in that topic, primarily involved Halc, David Cooper and myself (with some posts from Eduk and others).
I believe that at the heart of the discussion is the question of what the subject of Physics does and doesn't do, and aspire to do. David Cooper's central thesis is that the theory of Special Relativity, most associated with the name of Albert Einstein, contains logical contradictions which, he says, are as clearly contradictory as the statement "1=2". He believes that the alternative Lorentz Ether Theory contains no such contradictions.
The argument is that an observer who makes measurements against one reference frame is asserting things that contradict the assertions of an observer who makes measurements against another reference frame which is moving relative to the first one. The argument (as I understand it) proposes that there is only one possible reference frame that allows an observer to "accurately represent reality" and that this reference frame is stationary relative to the aether. The aether is/was the proposed medium through which light and other electromagnetic waves propagate.
My argument (and I think Halc's argument, but I'll let him speak for himself) is that observers do not make these assertions. They make measurements. And measurements that contain no errors are not misrepresentations. They are simply the measurements of a particular observer. I maintain that the central business of Physics is to propose invariants. That means abstracting those things from the measurements of individual observers which are proposed to be the same for all observers. I sometimes refer to these as "patterns" in observations. The laws of physics represent these proposed invariants.
The Principle of Relativity (as expounded by such people as Galileo and Newton) proposes that measurements of the mechanics of moving objects are unaffected by the relative motions of the reference frames against which those measurements are made, so long as those relative motions are at constant velocity. And since the Newtonian laws of mechanics are generalisations abstracted from those measurements, it follows that the laws of Newtonian mechanics are invariant across all non-accelerating reference frames. The Theory of Special Relativity extends this to the measurements and associated laws of electromagnetism.
What do you think? Do you think that the Principle of Relativity, and its extension to the Theory of Special Relativity, contains contradictions? Do you agree with my description of what the laws of Physics do?