Time Twists A Quantification of Entropic Boundaries Ultimately physics begs questions of ontology, epistemology, conceptual analysis--so to say philosophy. General relativity owes more to philosophical intuition, especially Mach's, than to tensor analysis. The first questions that arise are logical: How do tautologies mean, or, homologously, names name? (As in big bang cosmogony, physics illustrates conceptual isomorphisms with ancestral mythological schemata.) Maimonides quipped that reversal is the road to insight, mimicking perspective. A metaphor explained by Whitehead's recourse to generality. What do we tend not to doubt? That the past is past, complete, fixed, immutable, as Einstein believed, making, among science fiction fantasies, time travel impossible. What does this view assume? That words are names and objects essences. It is, as Wittgenstein would insist, a primitive view, or view of a language more primitive, or more specialized, than ours. The preliminary issue is thus conceptual--a priori the philosophers put it. Hume allows us to say that the future is logically unconstrained--that our theories are heuristic. Wittgenstein contributes to the conclusion that, reversing dogma, the past is contingent on the future--what something was, and is, depends on what it becomes. Since the future decides the past, the past is labile. Travel into the past does not violate logic. To recapture information of the past, one would have to exceed c. This is possible within quantum mechanical uncertainties of c. More precisely, Tb = (cml - h)/ml = c - k where Tb is the temporal or entropic boundary (time barrier), c is the speed of light, m is the rest mass, l is the rest length in the direction of motion, h is Planck's constant, and k is h/ml with units of velocity. The result is large, but testable with small particles. At speed Tb spacetime will relax ('untwist,' when extreme), and mass will disappear-- into past time. If Tb is not reached, the mass can create a black hole (which can otherwise be used to accelerate to Tb ). The phenomenon explains why black holes suggest singularities, and how they have not produced cosmological collapse through rapid mass accretion. At Tb mass will shift temporally and vanish.