Electromagnetic Spectrum

The electromagnetic spectrum covers a continuous range of electromagnetic radiation with varying frequencies and wavelengths. As the frequency of radiation increases, the wavelength becomes shorter and the energy higher. At the lower frequency end of the spectrum, radio waves have wavelengths ranging from hundreds of meters to less than one meter. These waves are commonly used for radio and television broadcasting, cell phones, wireless networking, GPS, radar, remote controls, other communication technologies. Microwaves, which have shorter wavelengths than radio waves, are frequently used in Wi-Fi networks or in microwave ovens for heating food. Infrared radiation is experienced by humans as thermal radiation, or heat. A small portion of the electromagnetic spectrum is occupied by visible light, the only type of electromagnetic radiation detectable by the human eye. This visible spectrum contains a range of colors from red to violet. Ultraviolet radiation, which is also emitted by the Sun along with infrared radiation, can cause sunburn due to its higher energy. At the shortest wavelengths and highest frequencies, X-rays are used in medical and industrial radiography, while gamma rays are produced by nuclear reactions and radioactive decay, and are sometimes used in medical treatments and diagnostics.