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9th Science Ch. 14
| answer | question |
|---|---|
| stiulated emission | the process that occurs when an exited atom is stuck by one photon and emists two photons |
| violet | color of visible light with the highest frequency |
| Max Planck | German scientist who showed tht the energy of an electromgnetic wave is irectly related to the wave's freuency |
| microwaves | waves commonly used for radar, satellite communications, and heating food items |
| radar | a device that uss reflected electromagnetic waves to measure the istance and direction of faraway objects |
| time dilaton | the apparent slowing down of time (from the perspective of an outside observer) for an object traveling at newr-light speed |
| refraction | the bending of light rays when they cross a boundary between two mediums |
| fiber optics | the technique of transmitting light through narrow glasslike "wires" used for communications |
| theory of relativity | states that all motion is relative to some reference point and that the speed of light is constant in relation to an observer |
| red | the color of visible light with the lowest frequency |
| visible spectrum | red, orange, yellow, green, blue, violet |
| electromagnetic spectrum | an arrangement of all forms of electromagnetic radioation in order of frequency and wavelength |
| Theodore H. Maiman | American scientist who constructed the first laser |
| radio waves | low-frequency waves widely used for communicaton |
| hologra | a three dimensional image produced by laser light |
| cherent | light in which all the waves are "in step" |
| particles | light acts like _____ when interacting with matter |
| X-rays | high frequency electromagnetic aves used in meicine, dentistry, andin airport security to "see" inside solid objects |
| white | a combination of all the colors of light mixed together is perceived as this |
| Wihelm Roentgen | German scientist who discovered X-rays |
| C | the speed of light in a vacuum |
| photons | light is descrimed as consisting of tiny bundles or "packest" of energy. these travel as the electromagnetic waves |
| particles theory of light | states that light canbe pictured as streams of tiny particles emitted by light sources |
| reflection | the boncing of light rays off a surface so that they continue in a different direction |
| coherent, intence, monochromatic | properties of laser light |
| James Clerk Maxwell | Scottish scientist ho discovered that light consists of electromagnetic waves |
| rainbow | visible spectrum produced in the sky by falling randrops |
| laser | light amplification by stimulated emission of rdiation |
| red, green, blue | the thre additve primary colors of light |
| UVB | the type of ultraviolet radiation that causes suntas and sunburn |
| Heirich Hertz | Germa scientist who first studied radio waves in the laboratory |
| iridescence | an array of many colors caused by the nterference of light waves often seen on the surface of soap bubbles and thin films of oil |
| diffraction | the spreading out of light waves aa result of passing though a narrow gap |
| nanometer | one billionth of a meter |
| black | the absence of all colors flight is perceived as this |
| lens | a piece of glass or other substance secifically designed to refract light |
| quantum thory of light | state that light has characteristics of both particles and waves |
| ultraviolet rays | electromagnetic waves responsible for tanning and subnburn |
| monochromatic | light that consists of only one frequency |
| Aristotle | Greek philosopher who taught that pure white lit contains no color |
| polarized | a beam of light containing wae that all vibrate in the same direction |
| mirage | an example is an illusion of "water" covering a hot highway i the distane in the summer |
| Christian Huyges | Dutch scientist who first proposed the wave theory of light |
| cyan, magenta, and yellow | the hree subtractive primary colors of piment |
| convex | a lens that is thickeer in the middle than at the edges, causes light rays to be concentrated and obectto appear magnified |
| infrared waves | electromagnetic wavs sometimes referred to as "heat waves" |
| Albert Einstein | Jewish scientist who redited stimulated emission and fomulated the theory of relativity |
| interference | the mtual reinforcement or cancellation of two light waves |
| Gamma rays | the most powerful and penetrating form of electromagnetic radiation |
| Isaac Newton | English scientist who discovered that white light is a combination of various other colors and frequencies of light; proposed the particles theory of light in his book Optiks |
| visible lig | electromagneticwaves tht our eyes can perceive |
| concave | a lens that is thinner in the middle than at the edges, causing light rays to be spreadout and objects to appear smaller |
| approximatly 300,000 kilometers per second or 300,000 km/s: the speed of light is always constant: it is the fastest possibl speed in the universe | facts about the speed of light in a vacuum |