Light is a form of electromagnetic radiation that is visible to the human eye. It is composed of particles called photons, which are elementary particles that carry energy. Light behaves both as a particle and as a wave, exhibiting properties of both.
In terms of its wave-like nature, light exhibits characteristics such as wavelength, frequency, and amplitude. The wavelength determines the color of light, with shorter wavelengths corresponding to blue or violet light, and longer wavelengths corresponding to red light. Frequency refers to the number of complete cycles of the wave that occur in a given time period.
Light can also be described in terms of its particle-like behavior. Photons, the particles of light, have no mass and travel at the speed of light in a vacuum, which is approximately 299,792,458 meters per second (about 186,282 miles per second). The energy of a photon is directly proportional to its frequency and inversely proportional to its wavelength, following the equation E = hf, where E is the energy, h is Planck's constant, and f is the frequency.
Light interacts with matter in various ways. It can be reflected, refracted, absorbed, or transmitted when it encounters different substances or surfaces. These interactions give rise to phenomena such as the colors we perceive, the formation of images through lenses, and the behavior of light in optical devices like prisms.
The study of light and its properties is known as optics and is a fundamental part of physics. It has significant applications in various fields, including telecommunications, astronomy, microscopy, and many branches of technology.