Psychohistory (fictional)

Psychohistory is a fictional science in Isaac Asimov's Foundation universe which combines history, sociology, and mathematical statistics to make general predictions about the future behavior of very large groups of people, such as the Galactic Empire. It was first introduced in the three short stories (1942–1944) which would later be collected as the 1951 novel Foundation.

Psychohistory depends on the idea that, while one cannot foresee the actions of a particular individual, the laws of statistics as applied to large groups of people could predict the general flow of future events. Asimov used the analogy of a gas: an observer has great difficulty in predicting the motion of a single molecule in a gas, but can predict the mass action of the gas to a high level of accuracy. (Physicists know this as the Kinetic theory). Asimov applied this concept to the population of his fictional Galactic Empire, which numbered a quintillion. The character responsible for the science's creation, Hari Seldon, established two axioms:

There is a third underlying axiom of Psychohistory, which is trivial and thus not stated by Seldon in his Plan:

Asimov presents the Prime Radiant, a device designed by Hari Seldon and built by Yugo Amaryl, as storing the psychohistorical equations showing the future development of humanity.

The Prime Radiant projects the equations onto walls in some unexplained manner, but it does not cast shadows, thus allowing workers easy interaction. Control operates through the power of the mind, allowing the user to zoom in to details of the equations, and to change them. One can make annotations, but by convention all amendments remain anonymous.

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