, is given as a function of the time,
, by the formula,
0 is the intensity of the initial radiation, and
a constant. This exponential law is completely defined by the knowledge of a constant of time that may be, for example, the inverse of
, is given as a function of the time,
, by the formula,
0 is the intensity of the initial radiation, and
a constant. This exponential law is completely defined by the knowledge of a constant of time that may be, for example, the inverse of