Visible light is being emitted from the hot element. Sources of short wavelengths X-rays are formed by smashing high energy electrons into other particles, such as metals. Gamma rays are emitted from nuclear reactions, atomic bombs, and explosions on the Sun and other stars. There are a number of different types of detectors of electromagnetic radiation. Your skin can also detect both visible light and infra-red heat rays.
Electronic devices are necessary to detect most of the longer waves, such as radio waves.
In conclusion Electromagnetic waves are transverse waves that travel at the speed of light. The spectrum of their wavelengths results in waves that are used in many of our useful devices. The waves are formed by heat, electronics, and nuclear forces. They are detected by devices. Jack Answer Television and radio waves have a very long wavelength, so they do not transmit as much energy as shorter wavelength radiation.