Archaeochronology seeks to establish absolute or relative dates for archaeological or paleoanthropological events. Therein, the scale, or the temporal resolution attainable, changes dramatically over the total time for human cultural and biological evolution. For radiometrically based dating methods, the half life (half lives) isotopic abundances, and contamination limit the intrinsic dating range, whereas factors, such as radiation dose, saturation effects, diffusivity, and chemical rates, limit other absolute archaeochronometers. As technology improves, however, precision usually increases, while the intrinsic dating limit can often be extended, thereby enhancing the scale. Even were the dating methods significantly more precise, contamination or sample degradation...