Abstract: Physicists, astronomers and cosmologists agree the universe is composed of an infinitesimal amount of matter and an overwhelming volume of space and time. While science labors to define reality in terms of mass and matter, and generally accepts the relationship between space and time, it has yet to define the nature of time itself. That definition is important because time is the medium in which all else exists. Time/life theory posits time is three distinct dimensions that coexist in a dynamic balance. It theorizes time is the foundation of physical existence, and life is its experience.