1, Underdetermination in relativity - The experiments that are said to be explainable by Einstein special relativity (SR) is said to be explainable by Lorentz ether theory (LET). (empirical evidence that can be explained by different theories is called underdetermination)
This then leads to false claims by physicists - they will start saying there is no ether, no preferred frame etc.
But those claims are just under the context of how SR interprets experiments.
In LET those same experiments are interpreted as having ether, preferred frame etc.
Thus those physicists who don’t add proviso to those claims that are meant in the context of SR are not stating things properly.
Also when they claim there is no ether, no preferred frame etc that is not what the experiments show. i.e. are making claims beyond what the experiments show
The experiments (Michelson-Morley, Kennedy-Thorndike, Ives-Stilwell, etc.) are underdetermined: they are equally compatible with Einstein’s Special Relativity (SR) and with Lorentz Ether Theory (LET). Both frameworks reproduce the same observable predictions for those tests, yet they differ radically in ontology, one eliminates any preferred frame and absolute simultaneity, the other retains a preferred frame (the ether) and absolute simultaneity while introducing length contraction and time dilation as real physical effects of motion through the medium.
Physicists frequently drop the crucial proviso “within the interpretive framework of SR” and state flatly “there is no ether, no preferred frame,” as if this were a direct experimental result. It is not. The raw data are silent on the choice between the two interpretations; the decision is philosophical or conventional, not empirical. This is textbook underdetermination.
We can recover the full set of Lorentz transformations and all weak-field GR effects from first physical principles without Einstein’s two postulates and without geometric abstraction (curved spacetime, Minkowski metric as primitive), with just basic assumptions:
No abstract postulates about constancy of (c) in all inertial frames or relativity of simultaneity are required. The transformations emerge directly from demanding continuity of a classical electromagnetic wave in a physically responsive vacuum. In gravity the observer’s own apparatus is strained by the same (n(r)), so the measured redshift is the full GR value; under acceleration there is no vacuum strain, recovering the observed half-effect (Sturm, Bertozzi reanalysis via Jormakka).
Thus SR and the weak-field limit of GR are not fundamental symmetries of spacetime but emergent consequences of wave propagation in a medium whose electromagnetic properties respond to mass/energy. The underdetermination Roger highlights dissolves once we supply the missing physical mechanism: the responsive vacuum supplies the exact structure that both SR and LET were attempting to describe, but without the interpretive baggage or unobservable entities.
The experiments do not force us to abandon a preferred frame or absolute simultaneity; they are fully compatible with a classical, local, causal ontology once we treat light as a continuous wave in a responsive vacuum. The choice between interpretations is no longer arbitrary in my work.
I’m not sure most people really understand that GR/SR are postulates and abstractions. Even in academic circle it’s taken for granted. There is no physical connections the effects, therefor it’s just a math abstractions. It’s just “curvature” or because of constant speed of light etc.. They assume global invariance yet gravity causes the Shapiro delay, red/blue shift by postulate. Nothing is properly derived from causality, phase continuity, or simply first principles.
Nobody is engaging with you Roger because most don’t understand underdetermination, postulate and abstraction. It was made to be acceptable in academia, but it’s not. Science as always been a Ptolemaic patchwork but we should always keep in mind it need to describe a physical reality without dark entities or other non-sense.
Relativity is taught badly to most people hence why they don’t understand the relevant issues of underdetermination etc. Anyway, I have problem here with this Forum - it does not allow too many replies from me.
correct.