Wave-particle duality is a fundamental concept in quantum mechanics that describes the dual nature of particles and waves. It suggests that particles, such as electrons or photons, can exhibit characteristics of both particles and waves depending on the experimental setup and the context in which they are observed.
In classical physics, particles are understood as discrete entities with well-defined positions and velocities, while waves are characterized by continuous oscillations and propagations through space. However, at the quantum level, particles and their behavior are described by wave functions, which are mathematical representations that exhibit wave-like properties.
Wave-particle duality implies that particles can exhibit wave-like properties, such as interference and diffraction, which are typically associated with waves. For example, in the famous double-slit experiment, when a beam of particles (such as electrons or photons) is directed toward a barrier with two slits, an interference pattern emerges on the detection screen behind the barrier. This pattern arises from the constructive and destructive interference of the particle waves passing through the slits, indicating the wave-like behavior of particles.
On the other hand, particles also exhibit particle-like behavior in certain situations. When measured, particles are found to possess well-defined properties such as position or momentum, akin to classical particles. This aspect of particle behavior is described by the principle of wave function collapse, which states that upon measurement, the wave function "collapses" to a specific value corresponding to the observed property.
Wave-particle duality is a central aspect of quantum mechanics and is essential for understanding various phenomena at the microscopic scale. It allows for a more comprehensive description of particles and their behavior, bridging the gap between classical and quantum physics.