Heisenberg uncertainty principle
parvaz-e nâtâštigi-ye Heisenberg
Fr.: principe d'incertitude de Heisenberg
The uncertainty in the measurement of the position and momentum of an elementary particle. The more precisely one quantity is known, the less certain the precision of the other. A similarly linked pair of quantities is the time and energy content in a volume of space.
Named after Werner Heisenberg (1901-1976), the German physicist who in 1927 derived the uncertainty principle. In 1932 he was awarded the Nobel Prize in Physics; uncertainty, from → un- "not" + → certainty; → principle.