Presented here is an empirical time-domain basis for classical mechanics and the associated derivation of c (where at c time=0) as a constant for the unique and independent references of non-zero mass bodies in relative motion. Here, general relativity shall be analysed and those energy requirements which lead to the cosmological constant problem and associated requirement for dark energy. To resolve the cosmological constant problem a new basis for the causality of mass and gravity as a new over-arching temporal scheme of cause-effect shall be presented as one that upholds the time-domain datum reference of physical phenomena of time-now, explaining why physical phenomena is associated exclusively to the time-now time-domain. Here also shall be derived the basis for the equivalence principle and associated conservation of momentum principle. In this process of derivation shall be presented a solution to the ”proton radius puzzle” also forming the basis for cosmic ray (solar wind) generation. Upon all of such shall be derived the known field forces with their empirical basis revealed, presenting the case for a unified field theory.