>>13960230Pretty much any mathematically formalized theory has numerous alternatives. This is what model theory studies, although primarily in a pure mathematical context. In more applied contexts, however, there are numerous candidates for a GUT, numerous ways of formalizing quantum mechanics (wave mechanics vs matrix mechanics), numerous ways of formalizing classical mechanics (HS/undergrad style physics that is basically the same system that Newton used, but with modern notation, Lagrangian mechanics, Hamiltonian mechanics, etc.), and numerous ways of formalizing pretty much any other area of physics. In other areas of applied math/science, we see the same thing. In biology, certain phenomenon can be studied using differential equations and network models, both of which are very different mathematically, but often produce the same results in application.
