Homework #1

One of the nearest stars is Alpha Centauri, whose distance is 4.2 × 10^16 meters. How long does it take light to travel from Alpha Centauri to us? (Hint: the speed of light is 3 x 10^8 meters/second) a. 140,000,000 years b. 4.4 days c. 4.4 years d. It is too far away to ever see e. 8.3 minutes

c. 4.4 years

If you were to specify your address in the universe, listing your membership from the smallest to largest physical structures, it would be: a. Earth, Local Group, Solar System, Andromeda, the universe. b. Earth, Solar System, Local Group, Milky Way, the universe. c. Earth, Solar System, Milky Way, Local Group, Laniakea Supercluster, the universe. d. Earth, Solar System, Milky Way, Laniakea Supercluster, the universe. e. Earth, Laniakea Supercluster, Milky Way, Solar System, the universe.

c. Earth, Solar System, Milky Way, Local Group, Laniakea Supercluster, the universe.

Because of _____________, we can conclude that gravity works the same way on Mars as it does on Earth. a. Newtons theory of relativity b. Einsteins special theory of relativity c. Sagan's planetary principle d. The cosmological principle e. the hypothetical statute

d. The cosmological principle

True or false? A "light year" is a way to measure distance.

true