The unsolved problems of physics stem from the unclear nature of the physical perception of change, and their resolution lies in the analysis of perception as a physical process. The unsolved problems of metaphysics stem from the same source, and can be resolved by the same perception analysis.
Specifically, a physical detection system can detect changes to itself and nothing else. These detected internal changes are thus what a detector "sees" or "observes" or "perceives" as changes to its external environment, i. e., as its physical phenomena. Thus a mass, being itself a physical detecting system, must detect only changes to itself, and these perceived changes to itself constitute its observed physical phenomena. For that reason, these perceived changes are obviously entirely relative to (i. e., are part of) the perceiver (observer); more precisely, they are entirely relative to and part of the perceiver's mass, which is the detector that is doing the perceiving.
Since only changes are perceived by a mass, then mass's perception must be a differentiating process. Ergo, perceived physical phenomena are first derivatives of a higher, or more fundamental, reality. The nature of that higher reality is by definition unperceivable (perception differentiates or fragments it), and it involves the quantity "action."1 Action itself is not perceivable; change of action is perceivable since perception differentiates action. If superposition is placed on the Heisenberg uncertainty principle as a required condition, then the uncertainty principle contradicts itself for all except integral or zero multiples of a quantum of action. Correction of the uncertainty principle by imposing superposition as a condition provides a statement of the basic operation of perception -- the detection by a mass of change to itself.
All mental perception of a human being regarding physical phenomena is received (i. e., is inputted to the mind) from a physical sensory apparatus whose primary ingredient is mass. Thus we may describe the perceptive mind as consisting of sensory outputs of mass perceptions; that is, the input to mental perception must be the output of mass perception, and this interface within the mind may be referred to as the "perceptive mind."
From the above foundation, a comprehensive theory of perception can be
constructed, and a most unusual model of "reality" emerges. A variety of
unsolved questions are then resolved by the model. The resolutions include,
among other things, 1) derivation of the postulates of relativity; 2) definition of
the nature of time and space; 3) the explanation of gravity; 4) the generation of
causality itself; 5) resolution of the wave theory of light with the quantum theory
of light; 6) the explanation of why ultramicroscopic phenomena are statistical
yet large ensembles of ultramicroscopic phenomena are causal; and 7) validation
of Mach's principle and the equivalence principle. A totally new and precise definition of mass and of
being itself are also two unexpected results. The
problems of metaphysics are also answered: metaphysics is elevated to an
exact science without any tinge of dogma, and physics and metaphysics are
1Planck's constant, Heisenberg's uncertainty principle, the principle of least action, the energy of a photon, etc., are derived from action and perception's differentiation of action.