| accelerator |
in nuclear physics, a device that creates high-energy particles by acceleration through electrostatic or electromagnetic means, used for research. [1/3 definitions] |
| actinic rays |
electromagnetic radiation, such as x-rays or ultraviolet light, that can produce an image on a photographic emulsion. |
| antenna |
a metal device that sends or receives electromagnetic signals. [1/2 definitions] |
| atomic clock |
an extremely accurate timekeeping device regulated by the reliably constant frequency at which atoms of certain highly reactive substances absorb or emit electromagnetic radiation. |
| backscatter |
the deflection, by electromagnetic or nuclear forces, of moving waves or particles away from their original direction at angles greater than ninety degrees. |
| bioelectricity |
the scientific study of biological electric currents and fields and of the effects of external electromagnetic forces on biological systems. |
| bremsstrahlung |
electromagnetic radiation, such as x-rays, produced by the sudden deceleration or acceleration of an electron caused by its approach to an atomic nucleus. |
| carrier |
the electromagnetic wave that is modulated to transmit a signal; carrier wave. [1/6 definitions] |
| diathermy |
medical treatment of localized tissues by heating with electromagnetic waves. |
| dielectric heating |
the heating of electrically nonconducting materials by exposure to a high-frequency, alternating electromagnetic field, as in the production of plywood. |
| echo |
a reflected electromagnetic wave, as in radar. [1/8 definitions] |
| electromagnetic spectrum |
the entire range of electromagnetic frequencies from radio, the lowest, to gamma rays, the highest. |
| electron gun |
the electron-emitting cathode in a cathode ray tube together with the electromagnetic apparatus that collects and focuses the electron stream. |
| EMI |
abbreviation of "electromagnetic interference." |
| EMP |
abbreviation of "electromagnetic pulse." |
| ether |
formerly, the substance believed to constitute outer space, and to be the medium of electromagnetic waves, including light. [1/4 definitions] |
| fluorescence |
the giving off of electromagnetic radiation, esp. in the form of visible light, during or after exposure to radiation from another source such as ultraviolet light or x-rays. [1/2 definitions] |
| fluorescent |
able to react to external radiation by emitting electromagnetic radiation, usu. in the form of visible light. |
| force of nature |
in physics, any one of the fundamental forces that occur in nature, including electromagnetic force, weak nuclear force, strong nuclear force, and gravitational force. [1/3 definitions] |
| frequency |
in physics, the number of electromagnetic waves that pass a certain point in a given time period. [1/3 definitions] |
| gamma ray |
electromagnetic radiation of high energy and frequency, produced by reactions of radioactive atoms or by high energy electrons interacting with matter. |