Nature's Time-scale: Degenerative Disease in Man

McCORMICK 1 recently formulated the following hypothesis: “All naturally occurring phenomena proceed according to exponential functions of time and each process in Nature conforms to its own unique time-scale”. He finds that the empirical equation describes a variety of different processes arid that the values of the constants k and c are characteristic of the particular process. Fremlin 2 points out that for any natural phenomenon the value of t must be subjected to an arbitrary cut-off at some finite value and that this kind of law is usually restricted to processes which occur under controlled conditions. In replying to Fremlin's 2 objection that equation (1) is incapable of describing periodic phenomena, McCormick 3 concedes that in such situations a series of exponential growth and decay functions are needed, each valid within certain limits of t .