Скачать или смотреть 1st Year Physics Light Has Particle or Wave Nature Ch#9

Light has a dual nature, meaning it can behave as both a particle and a wave:
Particle
Light behaves as a particle when it travels in a straight line. The particle model of light is known as the photon, which explains how light travels in straight lines.
Wave
Light behaves as a wave because it has a frequency, wavelength, period, and phase. It can also be refracted when traveling through different media. The wave nature of light explains how light bends around an object.
This dual nature of light is explained by the quantum mechanical wave particle duality theory. The original double-slit experiment performed by Thomas Young in 1801 showed that light acts as a wave. However, further experiments showed that light actually behaves as both a wave and as particles.