Vocabulary # 5 (The Tools of Astronomers)

Definitions

1. universe: everything that exists
2. telescope: a device that collects light and make distant objects appear closer and larger
3. refraction: the bending of waves as they go from one substance to another
4. reflection: the bouncing of waves of a surface
5. wavelenght: the distance from one peak to the next in a wave
6. frequency: the number of waves that pass through a point in a second
7. electromagnetic spectrum: waves of light in order by wavelenght

Sentences and illustrations

1. The content of the universe include stars, galaxies, and planets.

2.  Astronomers observe the universe and try to explain it by using telescopes.

3. Refraction of light is the basis of eyeglasses and some telescopes.

4. Mirrors and some telescopes use reflection.

5. Wavelenght is measured in meters.

6.  Frequency is measured in cycles per second, or hertz.

7. Electromagnetic spectrum shows waves of light in order of their wavelenght.