The Original Schrödinger's Cat Revisited: Schrödinger's Quantity

Originally introduced in Schrödinger's Cat as “a tiny amount,” we generalize this concept and introduce Schrödinger's quantity, a measure of radioactivity from the beginning to the first decay occurrence, or the starting point of radioactive decay. Schrödinger's quantity describes the radioactivity of a given radioactive isotope by the amount, or number of atoms, corresponding to a one-half probability that a decay occurs during one half of the isotope's half-life, whereas half-life measures radioactivity from the beginning to the midpoint of radioactive decay.