The nature of light has been a topic of scientific investigation for centuries. In the realm of quantum physics, light can be described both as a particle and as a wave, depending on the experimental context. This duality is known as the wave-particle duality of light.
In certain experiments, light exhibits particle-like behavior, and it can be described as a stream of particles called photons. Photons are massless particles that carry energy and momentum. They can interact with matter and exhibit properties such as being absorbed, emitted, or scattered. This particle-like behavior of light is well described by quantum electrodynamics (QED), which is a quantum field theory that explains the electromagnetic interaction between light and matter.
On the other hand, light also exhibits wave-like behavior in various phenomena, such as interference and diffraction. These wave-like properties are described by the wave nature of light. According to classical electromagnetic theory, light is an electromagnetic wave consisting of oscillating electric and magnetic fields.
The wave-particle duality of light is not limited to light alone but applies to other elementary particles as well, such as electrons and other quantum particles. It is a fundamental principle of quantum mechanics that particles can exhibit both wave-like and particle-like characteristics.
In summary, while light can be described as a stream of particles called photons in certain contexts, it also exhibits wave-like behavior. The wave-particle duality of light is a fundamental aspect of quantum physics.