The behavior of light, as well as other elementary particles, can be described by the principles of quantum mechanics. According to quantum mechanics, particles like photons (which are particles of light) exhibit a phenomenon known as wave-particle duality. This means that they can behave as both particles and waves, depending on the experimental setup and how they are observed.
The behavior of light as a wave or a particle is not a matter of probabilities or percentages of being one or the other at any given time. Instead, it depends on the specific conditions of the experiment and the type of observation being made.
In certain experiments and observations, light exhibits properties that are more easily explained by treating it as a wave. For example, phenomena such as interference and diffraction, where light waves can interfere constructively or destructively, are best understood using wave-like behavior.
On the other hand, in other experiments and observations, light behaves more like discrete particles, with properties such as energy quantization and the ability to interact with matter at specific points or in quantized amounts. This particle-like behavior is evident in phenomena like the photoelectric effect, where light can knock electrons out of a material in discrete packets of energy called photons.
The dual behavior of light can be attributed to the underlying principles of quantum mechanics. The wave-particle duality arises from the mathematical formalism used to describe quantum systems, such as the wave functions and the probabilistic interpretation of their squared magnitudes.
It's important to note that the behavior of light, as with other quantum particles, is not always intuitive from a classical perspective. While the wave-particle duality might seem counterintuitive, it is a fundamental aspect of quantum mechanics and has been extensively verified through numerous experiments.