uncertainty principle

the principle, introduced by German physicist Werner Heisenberg (1901–1976), that it is impossible to measure accurately both the position and the momentum of a particle at a specific moment in time. It arises from the fact that the act of measurement will itself interfere with the system being measured in unpredictable ways. The same principle applies to other paired variables, such as energy and time. The uncertainty principle has implications for philosophy, in that it appears to undermine the laws of cause and effect. Also called Heisenberg principle; indeterminacy principle.

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Psychology term of the day

May 9th 2024

equity theory

a theory of justice regarding what individuals are likely to view as a fair return from activities involving themselves and a number of other people. The theory posits that people compare the ratio of the outcome of the activity—that is, the benefits they receive from it (e.g., pay, fringe benefits, intrinsic gratifications, recognition)—to their inputs (e.g., effort, seniority, skills, social status) with the outcome-to-input ratios of those engaged in a comparable activity. Outcomes are equitable only when people receive benefits that are proportional to their inputs. See external inequity; internal inequity; overpayment inequity; underpayment inequity.