Bayesian Probability and One Bad Apple
DOI: 10.1063/1.1580035
The brilliant, attention-capturing sentences at the beginning of Michael Berry’s “Singular Limits” (Physics Today, May 2002, page 10 ) appear untenable unless one considers conditional (Bayesian) probability. In fact, biting an apple and finding no maggot may indicate either the worst or the best experience of the apple eater. Respectively, the eater may have swallowed the entire maggot with some bite or no maggot at all. The outcome depends on a preexisting condition: the presence, or absence, of a single apple inhabitant.
Real things may be even more complex: A particularly unfortunate eater may have gotten an apple with multiple maggots. The situation described also appears to be a suitable illustration of the collapse of probability by observation.
More about the authors
Bruno Lunelli, (blunelli@ciam.unibo.it) University of Bologna, Bologna, Italy .
