Chapter 23
Astronomy Journey to the Cosmic Frontier · 9 exercises
Problem 1
What is meant by the statement that "a telescope is a time machine"?
4 step solution
Problem 5
How can the stars in an elliptical galaxy be orbiting the center of the galaxy if the galaxy has essentially no angular momentum?
4 step solution
Problem 7
Why is a galaxy much more likely to collide with another galaxy than a star is to collide with another star?
4 step solution
Problem 9
What evidence do we have that there is dark matter in spiral galaxies?
3 step solution
Problem 11
What are some of the objects that serve as primary distance indicators in determining the cosmic distance scale?
5 step solution
Problem 12
Why can't primary distance indicators be used to find the distances of very distant galaxies?
5 step solution
Problem 13
Suppose we were to discover that all of the galaxies are actually ten times farther away than previously thought. What effect would this have on the value of Hubble's constant?
6 step solution
Problem 14
Describe how Hubble's law is explained as a consequence of the expansion of the universe.
4 step solution
Problem 15
Suppose we lived in a universe in which the greater the distance to a galaxy, the faster that galaxy were approaching us. How could such a relationship between distance and velocity be explained?
4 step solution