Blog on Math Blogs

Mathematical Digest

Short Summaries of Articles about Mathematics
in the Popular Press

"Gambler's Paradox" by R. Dean Astumian, Scientific American, July 2001, p. 62.

The title refers to a game designed to show an apparent paradox related to Brownian motion-specifically to molecular devices known as Brownian ratchets. The game consists of two games each of which has a negative expected value for the player. Yet if the player switches between the two games, the expected value is positive. The parallel to Brownian ratchets is that the ratchets allow a system to gain energy by alternating between two states, each of which loses energy. Simpson's paradox is described briefly in the article which appears as a sidebar within the article "Making Molecules into Motors" (pp. 56-64).

--- Mike Breen