Definitions for the response of materials in extremes across subject areas, mathematical descriptions and physical states are becoming increasing complex as interest multiplies. The region of interest in mechanical loading covers a range of pressures from the elastic limit to the point at which inner-shell electrons begin to contribute to new electronic states. The time for which the impulse is applied determines a volume element over which a strength is determined by sensors sampling with a particular temporal resolution; a local variable of space and time. A series of examples is given to show that only a shock probes the kinetics by which the steady wave is established and local equilibrium achieved. The term Akrology defines the science and engineering of these extreme states. © 2012 American Institute of Physics.