| fluor |
any compound that fluoresces when exposed to radiation, often added to experimental samples as a radiation indicator. [1/2 definitions] |
| fluoresce |
to exhibit, produce, or undergo radiation, esp. to emit visible light during or after exposure to radiation. |
| 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. [2 definitions] |
| fluorescent |
able to react to external radiation by emitting electromagnetic radiation, usu. in the form of visible light. |
| fluoroscope |
a fluorescent screen used with x-rays or other radiation for viewing the internal structure of opaque objects such as the human body. |
| gamma ray |
electromagnetic radiation of high energy and frequency, produced by reactions of radioactive atoms or by high energy electrons interacting with matter. |
| Geiger counter |
an instrument that detects radiation by means of a gas that ionizes when in the presence of radioactive emanations, and that also measures it by a device that counts the electrical pulses emitted by the ionized gas. |
| greenhouse effect |
the warming trend on the surface and in the lower atmosphere of a planet, held by scientists to occur when solar radiation is trapped, as by emissions from the planet. |
| hot spot |
an area of esp. high heat or radiation. [1/4 definitions] |
| infrared |
the invisible electromagnetic radiation next to and longer in wavelength than those of the visible red end of the spectrum. [1/2 definitions] |
| insolation |
solar radiation received, or the rate of solar radiation per unit of surface or area. [1/3 definitions] |
| ionosphere |
layers of the earth's atmosphere located above the stratosphere from about thirty to two hundred and fifty miles above the earth's surface, and composed of rarefied gases that have been ionized by radiation from the sun. |
| irradiate |
to expose to radiation, esp. as a medical treatment. [1/3 definitions] |
| irradiation |
emission of electromagnetic radiation, or the state of being exposed to such radiation. [2 definitions] |
| lamp |
a similar device that emits heat or radiation. [1/3 definitions] |
| langley |
a unit of illumination used for measuring solar radiation, equal to one small calorie per square centimeter. |
| laser |
a device that amplifies electrical impulses at mixed frequencies in or near the range of visible light by stimulating the atoms in a medium such as a gas or crystal, producing an intense, concentrated beam of light at one or more virtually distinct frequencies (acronym for "light amplified by stimulated emission of radiation"). |
| lead2 |
a chemical element that has eighty-two protons in each nucleus and that occurs in pure form as a very dense, malleable bluish gray metal used in many applications requiring high density, such as radiation shielding, shot, and weights. (symbol: Pb) [1/10 definitions] |
| light1 |
electromagnetic radiation, esp. from the sun, that enables one to see objects. [1/13 definitions] |
| luminosity |
the relative quantity of light or other forms of radiation produced by something, such as a star. [1/2 definitions] |
| maser |
a device that amplifies electromagnetic waves and concentrates them at a single microwave frequency (acronym for "microwave amplification by stimulated emission of radiation"). |