Man's physical universe

xanabras

08 THE UNIVERSE A VAST SYSTEM OF PARTS

36 inches to 72.5 inches, and more than forty large refractors in use

throughout the world.

STUDY QUESTIONS

1. Give the principles of the two types of telescopes.

2. What type of telescope is used at (a) the Mount Wilson Observatory, (b) the

Yerkes Observatory, (c) the Lick Observatory?

3. Which type of telescope should be used for observing the details of the surface

of the moon, and why should that tyjje be selected?

4. What type of telescope did Galileo use?

5. Why are many telescopes located on mountains?

6. How are modern telescopes kept focused on a given star as the earth moves?

7. What is a light-year?

8. Of what possible value will the 200-inch telescope be to humanity?

9. Why is the 200-inch mirror made from "Pyrex" glass?

10. Why are the largest telescopes reflectors rather than refractors?

11. What determines the magnifying power of a telescope?

12. What are the relative advantages and disadvantages of reflecting and refracting

telescopes?

13. What are the functions of the objectives in telescopes?

14. Inasmuch as telescopes do not depend upon magnification to see distant stars,

how do they enable us to see stars invisible to the unaided eye?

15. What is spherical aberration, and how is it overcome?

16. What is chromatic aberration, and how is it overcome?

17. What is meant by the resolving-power of a lens?

18. Why are very large refractors less practical than very large reflectors?

More magazines by this user
Similar magazines