The Theorum, where c2 is Time, I don't think can ever be proved wrong.
I'm working on developing hypothesis which may mean the c2 in the theory - speed of light x speed of light may be able to be reduced to just a single 'c' at particle physics level (only), in situations whereby Higgs bosuns and quarks are doing most of the work. As they may well exist, enter and return to be in higher fields above 3 dimensionsal space.
Along the lines of, for example, Entropy Physics, think towards into: Macroscopic Systems; only Time, i.e. the theorum, is relavent.
Into this macroscopic system there will be microscopic systems operating Newton's 4th Law etc. (Think of the solar system, for example). Where the theory identifies these force - force actions. But at particle physics level, you could potentially identify the fact of quarks changing neutron hosts as a one-way journey, with drag being the force replacing an opposite reaction, and the Theorum governing the overriding system (or the Law of Efficiency in Nature), whatever way you want to look at it, are forcing the initial movement of these sub-atomic particles.
What I mean is that Einsteins theory only counts as c2 is Newtons 4th Law is occuring. Sub-atomic particles potentially don't succumb to the 4th Law as they 'disappear' into higher fields.
I'd also be interseted to see in the future whether anyone conforms this theory is just in relation to Light Energy. I have a feeling Dark Energy will have a similar but alternative formula, something like E=mg2 c, where mass and gravity are squared and light speed is a control value for comparing results and governing the workings.
Sorry! Yeah, I can't use generic terms lol. I'm also a fan of Einstein, so I'd have to be able to use my own body or eyes as a) part of the experiment, and b) instruments for recording data within that experiment.
Are you aware of dimensional analysis? It means that equations must be dimensionally consistent. The dimensions on either side must match. Thus if you make changes like v to v^2 you must change the other side by v (or distance / time, which corresponds).
It is a way of checking that an equation is still viable.
If it is not dimensionally consistent, it must be wrong.