The Online Encyclopedia and Dictionary






Radiant energy

Radiant energy is energy that is transported by waves. Radiant energy may be calculated by integrating radiant power with respect to time. Radiant energy is usually expressed in joules. This includes energy transception in the form of waves through space or various media. solar energy is radiant energy. Radiant energy is also energy transfered through electro magnetic waves. Solar Energy is a type of radiant energy.



Radiant energy refers to the energy of electromagnetic radiation. Since all EM radiation is photon-based, radiant energy is the energy carried by the relevant photons. Radiating bodies have typical portions of the electromagnetic spectrum in which their radiation is concentrated. Such radiating bands may be sharply defined, such as is seen in star spectra, or may be more diffused.

EM radiation has three principal components: wavelength and frequency, which are strictly inversely proportional, and intensity, which determines the amount of energy carried by the radiation. Radiant energy may be originated in a body or reflected from another body (in which case it may be refracted or otherwise modified).

Open systems

Open systems are sometimes referred to as "radiant energy" systems because of the circuit (a phantom loop) that includes the environment. In geophysics, transparent greenhouse gases trap the sun's radiant energy (at certain wavelengths), allowing them to penetrate deep into the atmosphere or all the way to the Earth's surface, where they are re-emitted as longer wavelength radiation (chiefly infrared radiation). Radiant energy produced in the sun is a result of nuclear fusion and some of it, ultimately, interacts with the earth's atmosphere and surface.

Applications and patents

Radiant energy, as distinguished from convective and conductive energy, is used for heating homes. One of the earliest wireless telephones was based on radiant energy. The device had its resonance tuned to a particular frequency of other repeaters to communicate between each. According to Nikola Tesla, it was the "... [S]implest ways [to detect the radiant energy ...] the low frequency gave audible notes. [... in a field, there was] placed a conductor, a wire or a coil, and then [Tesla] would get a note [...] characteristics of the audible note".

The United States Patent Offices has a classification of radiant energy for patent applications (Class 250, a residual class for methods and apparatus involving radiant energy). This class provides for all methods and apparatus for using, generating, controlling or detecting radiant energy, combinations including such methods or apparatus, subcombinations of same and accessories therefore not classifiable elsewhere by the patent office. [1]

SI radiometry units

See also



References and external links

Last updated: 05-07-2005 07:06:26
Last updated: 05-13-2005 07:56:04