Heisenberg’s uncertainty principle

Definition

Heisenberg's uncertainty principle states that it is impossible to simultaneously determine both the position and momentum of a particle with absolute precision. The more accurately one of these properties is measured, the less accurately the other can be known.

5 Must Know Facts For Your Next Test

1. The principle is mathematically represented as $\Delta x \cdot \Delta p \geq \frac{h}{4\pi}$ where $\Delta x$ is the uncertainty in position, $\Delta p$ is the uncertainty in momentum, and $h$ is Planck's constant.
2. It highlights a fundamental limit to measurement precision inherent in quantum systems.
3. The principle challenges classical mechanics where objects can have precisely determined properties.
4. It has profound implications for understanding atomic and subatomic particles' behavior.
5. Heisenberg's uncertainty principle underpins many phenomena in quantum mechanics, such as wave-particle duality.

Review Questions

• What does Heisenberg's uncertainty principle state about measuring position and momentum?
• How does increasing the accuracy of measuring a particle's position affect the accuracy of measuring its momentum?
• What are the implications of Heisenberg’s uncertainty principle on classical physics?

Related terms

Planck's Constant: A fundamental constant denoted by $h$, which is used to describe the sizes of quanta; its value is approximately $6.626 \times 10^{-34} Js$.

Wave-Particle Duality: A concept in quantum mechanics stating that every particle or quantum entity exhibits both wave and particle properties.

Quantum Mechanics: The branch of physics dealing with phenomena at very small scales, typically at the level of atoms and subatomic particles.