- Light
Light is a form of energy or electromagnetic radiation that is visible to the human eye.
Light consists of photons, which are particles that carry energy in the form of waves. These photons carry energy and can move through space without needing a medium, unlike sound or heat, which typically require matter to propagate. Light travels through space at a constant speed and can interact with matter in various ways, including reflection, refraction, and absorption.
Light travels through space at a constant speed, specifically the speed of light, which is approximately 299,792 kilometres per second (km/s) in a vacuum. This is a scalar quantity, representing how fast light moves without specifying direction.
The energy of light is determined by its wavelength or frequency, with shorter wavelengths (such as ultraviolet or X-rays) carrying more energy, and longer wavelengths (such as infrared) carrying less energy.
In the context of fire, light is produced as a result of the energy released during the combustion process. This light energy is part of the radiant energy emitted by the fire, along with heat (infrared radiation).