1	Astr 5460 Wed., Mar. 12, 2003 Today: Reminders/Assignments Longair, Ch. 5-6 - Getting into Theory/GR (Ch. 5+) - Hogg papers Unless noted, all figs and eqs from Longair.
2	Reminders/Preliminaries Mini-Exgal-TAC on Friday Any questions at this stage? Try not to discuss with each other too much in advance, that will happen Friday Register an account on MAST? WIRO over spring break: Camera on and working, clusters selected I’ll go 1-3 nights – who else? Discuss logistics No class on Wed. March 26
3	Ex-gal TAC Assignment Next Friday in place of our usual astro-ph preprint discussion. 12 proposals, everyone has two primary proposals to lead the discussion about, plus two secondary proposals. Everyone must read all proposals and note strengths and weaknesses, and assign a preliminary grade (1=best, 5=worst), in accordance with guidelines. I’ll chair the meeting and evaluate performance. I expect this will be a challenging but very educational experience.
4	Theoretical Framework Section 5.1, the “Cosmological Principle” Isotropic, homogenous, uniform expansion Can write relativistic equations in different forms (famous names cited here…) Weyl’s postulate: “The particles of the substratum (representing the nebulae) lie in space-time on a bundle of geodesics diverging from a porint in the (finite or infinite) past.”
5	Theoretical Framework Section 5.1, the “Cosmological Principle” Geodesics are “world-lines” of galaxies and do not intersect except at a singular point in the past. Weyl’s idea predates Hubble’s law. Fundamental observers on each world line, each with standard clock measuring cosmic time from that singular point. “We are not located at any special location in the universe.”
6	Theoretical Framework Sections 5.1-5.4 cover underpinnings of GR (curved spaces, space-time metrics) and in particular the Robertson-Walker metric that we will need to describe the universe. Read and follow these sections, but we don’t have the lecture time to go into much detail with the perspective of observational astronomers in a mixed galaxies/cosmology course.
7	Theoretical Framework Section 5.5 covers observables. We’re going to jump to the chase momentarily and walk through Hogg (2000), which integrates this material with world models (Chapter 7, and a Sandage review article I will probably assign soon.)
8	Theoretical Framework
9	Theoretical Framework
10	Theoretical Framework Chapter 6 introduces General Relativity, which I won’t go over in class. Again, read through it. I expect to cover chapter 7 following spring break. WIRO and an observing manual are the “homework” over spring break…I hope!