Preflight 1

Post your response on the course Compass site

Due Friday, Jan. 31, 9am

Reading

Course Text

Peacock

Chapter 1; Chapter 3

The first chapter is a discussion of General Relativity. After some nice conceptual discussion, the rest of the presentation becomes a bit dense and probably is challenging for a neophyte to GR.

The third chapter is Peacock's opening discussion of cosmology, but comes after chapters on astrophysics and relativity. As such, it's rather direct, not a "chatty" or informal easing into the subject, and is focused on establishing the basic concepts and their mathematical description. For a broader review with a wider focus, see some of the supplemental readings.

Articles

Michael S. Turner

"Cosmology Solved? Quite Possibly!"
Publications of the Astronomical Society of the Pacific (1999) 111, 264-273
arXiv:astro-ph/9811364; Published article: PDF version

This is a dates but very accessible and exuberant review which captures the spirit of excitement in cosmology. It is interesting to read in the light of what has and has not occurred since it was written.

Suggested Supplemental Reading

John C. Baez and Emory F. Bunn

"The Meaning of Einstein's Equation"
Amer. Jour. Phys. 73 (2005), 644-652
arXiv:gr-qc/0103044

This is a brief but conceptual review of some of the essentials of General Relativity. The authors consciously try to avoid mathematical detail and to appeal to key physical and geometrical principles.

Sean Caroll

"Lecture Notes on General Relativity"
online html version
arXiv: gr-qc/9712019
Book: Spacetime and Geometry: An Introduction to General Relativity

Questions

The questions are really meant to help guide your thinking as you read. You may find it helpful to look at the questions first and bear them in mind as you read.

Post your answers on Compass. Your answers must be in your own words.

1. Discussion Question 1

   Distinguishing a big bang universe from a steady state universe. Posted on Compass; your reply will be visible to your classmates.

2. Introductions.

   We'd like to know a little bit about you for our files. Briefly, what is your background, if any, in astronomy/astrophysics? In nuclear/particle physics? If you are already involved in research, what are you working on? If you are not, what area(s) interest you?

   Are there specific topics would you like see discussed in this course?

3. Cosmology solved?

   For inspiration and a view of the big picture (as of 16 years ago), read the Turner article.

   1. In the introduction, Turner quickly outlines the basic physics of big bang cosmology, and highlights the "three pillars" of evidence which provide the strongest support for the theory. what are they? What is strongest evidence for them?
   2. In your view, to what extent is cosmology solved?
   3. What questions/issues in cosmology remain unsolved--not only those Turner mentions, but others that occur to you? What would you add to Turner's checklist for this decade in cosmology?
   
   
4. General Relativity.

   Take look at either the initial discussion in Chapter 1 of Peacock, and/or the Baez & Bunn article, and/or the very nice first paragraphs of Chapter 4 in Carroll, reading for concepts more than for the formalism. Clearly, this reading is not going to teach you General Relativity from scratch, but is only meant to give you a flavor of the philosophy and some of the results of this beautiful theory. To really understand GR, take Stu Shapiro's course!

   Given these limited goals with respect to GR, the questions here are just to help you think about the basics.

   1. What is the equivalence principle? State it as clearly and precisely as you can. Also state it in simple everyday terms you would use when talking to someone at Kam's or a similar non-scientific institution.
   2. Give an example of an experiment which verifies the equivalence principle.
   3. How could the equivalence principle be used to argue that gravity is not a force but rather has a geometrical explanation?
   4. What does it mean to say space is curved? What is an experiment you can do to determine if you live in a curved space but you and your measuring device are much smaller than the curvature radius? (Hint: the surface of the Earth is an excellent example.)
   5. Bonus for style points: What does it mean to say spacetime is curved? What is an experiment you can do to determine if you live in a curved spacetime (hint: the surface of the Earth is one)?
   
   
5. What material did you find difficult, confusing, or unclear? What material would you like to know more about?