Problem set 9 for ASTR 222: From Stars to Cosmology
Due in class Wed April 13.
(1) This problem is intended to get you to better understand the
intuitive aspects of an expanding universe with a finite age by explaining it
successfully to a friend.
Kutner problems 20.2, 20.3, 20.5, 20.7, 20.11
(a) Write 1-2 paragraphs on your own conceptual difficulties
understanding a universe where space itself is expanding, rather than
the universe expanding into something, and what you found useful in
getting an accurate idea about it. You should also talk
about its unbounded or infinite spatial extent and its finite age.
(b) Now choose a friend who is not a physics or astronomy
major. Sit down with them and explain the concepts you discussed in
(a). Write 1-2 pages on your interaction with your friend -- did
they find it easy to understand what you were talking about? Why or
why not? What strategies did you use to help explain things? Did they
have any particular misconceptions? Were their misconceptions and
difficulties the same as yours or different? Was it a successful
interaction? (if not, keep trying .......)
For extra credit -- explain Olbers' paradox and its resolution to
your friend too, and write up a description of this interaction.