This chapter discusses light and telescopes. It defines key terms like frequency and wavelength and discusses the electromagnetic spectrum. It provides information about light years and discusses how light from distant galaxies takes time to reach us. The chapter also covers the basics of different types of telescopes, including refracting, reflecting, and compound telescopes. It discusses components like the objective, aperture, focal length, and eyepiece and how they relate to magnification. Additional topics covered include defects in telescope mirrors and details of binocular specifications.

1. Astronomy: A Self-Teaching Guide
Ch. 02: Light and Telescopes
1. How can light be modeled?
2. Define: Frequency
3. Sketch a wave. Include crest, trough, and wavelength.
4. What is the wavelength range of human vision?
5. List three forms of “long” and “short” wavelength electromagnetic radiation.
Long Short
6. How many miles does one light year equal?
7. How long does light from the Andromeda Galaxy take to reach our eyes?
8. Complete the telescope chart:
Telescopes Refracting Reflecting Compound
Optics

2. 9. Matching:
_____ Objective a) Assembly of small magnifying lenses, forms the
image viewed through a telescope
_____ Aperture b) Diameter of the objective, determines amount of
light gathered by the scope
_____ Eyepiece c) Distance from the objective to the image in the
eyepiece
_____ Focal length d) Main mirror or lens
10. What magnification is produced by a 32mm eyepiece used with a 2000mm focal length Schmidt-
Cassegrain telescope?
11. What is the highest useful magnification of a 6-inch reflecting telescope?
12. What is the focal length of a 6-inch (150 mm), f/8 reflecting telescope?
13. What magnification would be produced when using the 6-inch scope mentioned above with a
32mm eyepiece?
14. Telescopes advertised as having high ____________________ are meant to deceive consumers
because ____________________ is the true way to access a telescope’s ability to show objects in
the sky.
15. If the mirror in our 6-inch scope had a defect, what might it be?
16. What is the aperture and magnification of a pair of 15x80 binoculars?
17. What is the term for the steadiness of the earth’s atmosphere over a given surface?
18. What is an observatory?