Radiation refers to the emission of energy as electromagnetic waves or as moving subatomic particles, commonly resulting from a nuclear reaction, nuclear decay, or the interaction of charged particles with matter. It is a process in which energy is transmitted through space as waves or particles. The waves can vary in their frequencies and wavelengths, ranging from the high-energy, short-wavelength gamma rays and X-rays to the lower-energy, longer-wavelength microwaves and radio waves.
Radiation encompasses various forms of energy, such as electromagnetic radiation (including visible light, infrared, ultraviolet, and radio waves) as well as particulate radiation (consisting of charged or uncharged particles). It can be natural, originating from sources like the Sun or other celestial bodies, but also artificial, produced by human activities or technological devices including X-ray machines, nuclear power plants, and radiotherapy devices.
The effects of radiation on matter are diverse and can include ionization (creating charged particles), excitation (raising electrons to higher energy levels), or even causing molecular and DNA damage. Due to its potential harm, exposure to excessive amounts of radiation can pose significant health risks to living organisms.
Furthermore, radiation plays a crucial role in various fields, such as medicine (diagnostic imaging and cancer treatment), industry (sterilization, food preservation), and scientific research (radiocarbon dating, astrophysics). Accurate measurement and protection against harmful radiation are essential to ensure the safety and well-being of humans and the environment.
