The elements heavier than hydrogen and helium of which the planets are composed probably came from the a. sun b. debris of supernova explosions that occurred before the solar system came into being c. big bang d. big crunch
Current ideas suggest that what is responsible for the observed properties of a quasar is a massive a. neutron star c. spiral galaxy b. black hole d. star cluster
. Distinguish between a closed and an open universe. How does the density of matter in the universe bear on the question of whether the universe is closed or open? What does present evidence suggest about the nature of the universe?
Planets are always small compared with stars because otherwise a. the rotation of the planets would cause them to disintegrate b. the great mass of the planets would cause them to be pulled into their parent star c. the great mass of the planets would prevent them from being held in orbit and they would […]
What is the evidence for the idea that dark energy fills the universe? Is the nature of dark energy known at present? How does the amount of dark energy compare with the amount of ordinary matter in the universe? With the amount of dark matter?
A radio telescope is basically a (an) a. device for magnifying radio waves b. telescope remotely controlled by radio c. directional antenna connected to a sensitive radio receiver d. optical telescope that uses electronic techniques to produce an image
1. Where is most of the interstellar gas in our galaxy located? What is its chief constituent? 2. Do radio telescopes magnify anything? If not, why are larger and larger ones being built? 3. List the three ways in which radio waves from space originate.
1. Are the stars uniformly distributed in space? 2. (a) Why is the sun considered to be located in the central disk of our galaxy? (b) What is thought to occupy the center of the disk? 3. What is the Milky Way?
1. What are the origins of the helium found in the universe? 2. To what event in the history of the universe can the cosmic microwave background radiation be traced? Was the radiation always in the form of microwaves? If not, what happened to change the wavelengths of the original radiation?
1. Did the planets come into being before, during, or after the formation of the sun? 2. Would you characterize the most likely next phase of the earths history as fire or ice? 3. Why is it reasonable to suppose that many stars besides the sun have planets orbiting them? Why does it seem unlikely […]