What does the wave-particle duality of light refer to?

The wave-particle duality of light refers to the concept that light possesses characteristics of both waves and particles. This fundamental principle is central to quantum mechanics and has been demonstrated through various experiments. For instance, the wave-like behavior of light is evidenced by phenomena such as interference and diffraction, where light displays patterns that can only be explained through its wave properties. On the other hand, light can also behave as discrete packets of energy, called photons, which illustrates its particle-like properties, especially evident in phenomena like the photoelectric effect, where light knocks electrons out of a material.

This dual nature indicates that light cannot be strictly classified as either a wave or a particle; instead, it is best understood as exhibiting both types of behavior depending on the circumstances of the observation or the experiment being conducted. Therefore, understanding wave-particle duality allows for a deeper comprehension of the interactions and behaviors of light in various contexts, bridging classical and quantum physics.