Hi Giovanni,
you essay is certainly not running short of originality! I see you also have a book on these issues.
I find the idea of a continuous model of space and time (the reals) that becomes discrete when viewed by the eyes of a young Einstein riding the light beam very original and somewhat attractive, although I have problems in understanding whether the two pictures can fit into a unique, coherent vision of the physical universe.
(I have a tendency to believe that discreteness is all we need to explain the physical world, with continuity and infinity arising as limiting concepts - purely logical products of our 'creative' minds. That the human brain can be creative 'beyond naturalness' is confirmed, for example, by the construction of the Reals by Dedekind, and the implied mental procedures.)
You write:
From a logical point of view, a model maintains the "truth-values", in the sense that all that is true of the object is also true of its model.
Shouldn't it be the reverse, that is: all that is true of the model should be true of the object? What the models says about the object must be true, but the model is not required to tell all truths of the object (otherwise the two would coincide).
A final remark. It is a fact that the order of events in *subjective* time may be reversed when passing from an observer to another observer, but the Lorentz distance (spacetime distance) between two events is constant for all observers, i.e. invariant under the Lorentz transformation. The Lorentz distance and associated lightcone structure define the causality relation between events, which is fixed. Lorentz metric and causality are the objective aspects behind subjective time.
Then, what would be wrong in saying that space and time, taken separately, are purely subjective intuitions (following Kant) and that spacetime (Lorentz) distance is the objective physical quantity behind them?
Saluti da Pisa!
Tommaso