Okuzeka
Physics vocabulary · Quantum and Modern Physics

Uncertainty principle

Meaning in physics, with examples

nounAdvanced term

In physics, uncertainty principle means: A rule of quantum physics stating that certain pairs of quantities, such as a particle's position and momentum, cannot both be known exactly at the same time.

In Turkish: belirsizlik ilkesi, Heisenberg belirsizlik ilkesi

How it is used

Also called Heisenberg's uncertainty principle and written Δx Δp ≥ ħ/2. It is a property of nature, not a limit of our instruments, and a similar relation links energy and time. Popular articles often explain it wrongly as the observer disturbing the particle.

Example sentences

  1. According to the uncertainty principle, the more precisely we know the electron's position, the less precisely we know its momentum.

  2. Heisenberg published the uncertainty principle in 1927.

Common collocations

  • Heisenberg's uncertainty principle
  • position and momentum
  • energy-time uncertainty
  • quantum uncertainty
  • quantumThe smallest separate amount of a physical quantity, such as energy, that can be absorbed or emitted. Light energy, for example, comes in quanta called photons.
  • wave-particle dualityThe idea that light and matter can behave both as waves and as particles, depending on the experiment. Electrons, for example, can produce interference patterns.
  • momentumThe product of an object's mass and its velocity (p = mv). It is a vector and is measured in kilogram metres per second (kg·m/s).
  • uncertaintyThe range within which the true value of a measurement probably lies, written with a ± sign. It shows how reliable a measurement or result is.
  • photonA single packet, or quantum, of electromagnetic energy. Its energy depends only on the frequency of the radiation: E = hf, where h is Planck's constant.

More terms: Quantum and Modern Physics

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