Final answer:
Light exhibits wave-particle duality, meaning it can display both wave-like and particle-like properties. Wave behaviors like interference and particle behaviors like the photoelectric effect exemplify this duality. The nature of light as being capable of existing in these two seemingly contradictory forms is a foundational concept in modern physics.
Step-by-step explanation:
The concept that light can be considered both a wave and a particle is known as wave-particle duality. Initially, experiments demonstrated that light exhibits wave-like behavior, seen through phenomena such as interference and diffraction. However, studies conducted in the 20th century revealed that light can also display properties characteristic of particles, leading to the acceptance that light sometimes acts as if it consists of discrete packets of energy called photons. The wave-like nature of light is evident in actions like the spreading of light waves, while the particle nature is observed in experiments such as the photoelectric effect, where light behaves as photons, each carrying a quantum of energy.
A key figure in this area is Einstein, whose findings contributed substantially to the understanding of light's dual nature. The photoelectric effect, which contradicted the wave theory of light, and the interference patterns from the double-slit experiment, which contradicted the particle theory of light, both demonstrated this duality. Therefore, light is believed to have the ability to behave as both a wave and a particle depending on the circumstances, an idea that remains one of the compelling mysteries in the field of physics.