This paper is a comparison of the Minkowski, Einstein and Einstein dual theories of relativity. The dual is based on an identity relating the observer time and the proper time as a contact transformation on configuration space, which leaves phase space invariant. The theory is dual in that, for a system of n particles, any inertial observer has two unique sets of global variables (X, t) and (X, τ) to describe the dynamics. Where X is the (unique) canonical center of mass. In the (X, t) variables, time is relative and the speed of light is unique, while in the (X, τ ) variables, time is unique and the speed of light is relative with no upper bound. The two sets of particle and Maxwell field equations are mathematically equivalent, but the particle wave equations are not. The dual version contains an additional longitudinal radiation term that appears instantaneously with acceleration and we predict that radiation from a betatron (of any frequency) will not produce photoelectrons. The theory does not depend on the nature of the force and the Wheeler- Feynman absorption hypothesis becomes a corollary. The homogeneous and isotropic nature of the universe is sufficient to prove that a unique definition of Newtonian time exists with zero set at the big bang. The isotopic dual of R is used to improve the big bang model, by providing an explanation for the lack of antimatter in our universe, a natural arrow for time, conservation of energy, momentum and angular momentum. This also solves the flatness and horizon problems without inflation. We predict that matter and antimatter are gravitationally repulsive and that experimental data from distant sources cannot be given a unique physical interpretation. We provide a table showing the differences between the Minkowski, Einstein and dual versions of the special theory.