| A | B |
|---|
| discovered that sunlight is a combination of many colors | Sir Isaac Newton |
| visible spectrum | red, orange, yellow, green, blue, and violet |
| a movement of energy from one place to another | wave |
| oscillation | a back and forth motion that repeatedly follows the same path |
| pulse | a single rise or depression in a series of waves |
| high point in the wave | crest |
| low point in the wave | trough |
| medium | whatever carries the wave |
| magnetic field | a region in which certain objects are attracted or repelled by a magnet |
| electric field | a region in which certain objects may be attracted or repelled |
| electromagnetic wave | a wave consisting of an electric field and a magnetic field vibrating at right angles to each other |
| electromagnetic waves do NOT need | a medium |
| James Clerk Maxwell | realized that light is a type of electromagnetic wave |
| speed of light | 186,000 miles per second |
| The speed of light measures | how fast electromagnetic waves travel |
| frequency | how fast the wave oscillates |
| wavelength | the length of one complete wave or cycle of oscillation measured from crest to crest or trough to trough |
| electromagnetic spectrum | an arrangement of electromagnetic waves according to frequency and wave length |
| telescope | a device to make distant objects appear clearer or closer |
| Galileo | the first astronomer to make extensive use of a telescope in his study of the heavens |
| two types of telescopes | refracting and reflecting |
| refracting | uses lenses |
| reflecting | uses mirrors |
| the turning back or turning aside of any wave when it hits and obstacle | reflection |
| refraction | the bending of any wave's direction at the boundary between two wave media |
| Sir Isaac Newton | developed the reflecting telescope |
| Hubble Space Telescope | a reflecting telescope with an 8-foot-wide main mirror launched into orbit around the earth in 1990 |
| spectroscope | splits light into the spectrum for analysis |
| radio telescopes | instruments that collect radio waves from space |
| pulsars | stars producing rapid bursts of radio waves |
