Using a temporal version of the Copernican principle, Gott has proposed a
statistical predictor of future longevity based on present age [J. R. Gott III,
Nature 363, 315 (1993)] and applied the predictor to a variety of examples,
including the longevity of the human species. Though Gott's proposal contains a
grain of truth, it does not have the universal predictive power that he
attributes to it.Comment: 17 pages, standard LaTeX; to be published in Contemporary Physic