| A | B |
|---|
| electromagnetic wave | made by vibrating electric charges that can travel through space where matter is NOT present |
| radiant energy | the energy carried by an electromagnetic wave |
| photon | particle that electromagnetic waves sometime behave like |
| radio wave | low-frequency electromagnetic waves with wavelengths longer than about 1mm |
| microwave | radio waves with wavelengths of less than about 30 cm |
| infrared wave | a type of electromagnetic wave with wavelengths between about 1mm and about 750 billionths of a meter |
| visible light | the range of electromagnetic waves that you can detect with your eyes |
| ultraviolet wave | electromagnetic waves with wavelengths from about 400 billionths to 10 billionths of a meter |
| X-ray | have wavelengths between about ten billionths of a meter and ten trillionths of a meter |
| gamma ray | highest energy electromagnetic waves that can penetrate through several centimeters of lead |
| opaque | material that absorbs or reflects all light and does not transmit any light |
| translucent | material that transmits some light but not enough to see objects clearly through it |
| transparent | material that transmits almost all light striking it so that objects can be seen clearly through it |
| index of refraction | property of a material indicating how much light slows down when traveling in a material |
| mirage | image of a distant object produced by a refraction of light through air layers of different densities |
| pigment | colored material that is used to change the color of other substances |
| incandescent light | light produced by heating a piece of metal, usually tungsten, until it glows |
| fluorescent light | light that results when ultraviolet radiation produced inside a fluorescent bulb causes the phosphor coating inside the bulb to glow |
| coherent light | light of a single wavelength that travels in a single direction with its crests and troughs aligned |
| incoherent light | light that contains more than one wavelength, and travels in many directions with its crests and troughs unaligned |
| polarized light | light whose waves vibrate in only one direction |
| holography | technique that produces a complete three-dimensional photographic image of an object |
| total internal reflection | occurs when light strikes a boundary between two materials and is completely reflected |
