PHYS 182 Lecture Notes - Lecture 1: Visible Spectrum, Parsec, Nuclear Fusion
PHYS182: Our Evolving Universe
2017-09-05 LEC 1
Introduction
• Professor: R. Brandenherger
o rhb@physics.mcgill.ca
• TAs: M. Anthonisen, Y. Tsiares
• Website: physics.mcgill.ca
• Textbook: Cosmic Perspective
• Grading format:
o Final – 30%
o Midterms (2) – 30% total
§ Oct. 12
§ Nov. 14
o Homework – 30%
o Report – 10%
1. Our Place in the Universe
1.1 – Our place in space
Dr. Brandenherger’s research
• Big bang: infinite density & temperature
• Understand the origin and early evolution of the universe
o What is the big bang? Was there a big bang? What came before?
• Explain observed large scale structures
o Patterns in the distribution of galazies on large scales
o Anistotrophies in CMB maps
• Make predictions for future observations
The night sky
• Individual objects in the milky way are of finite and non-finite size (to the accuracy we can
resolve them)
• There are planets and stars, but how can we tell the difference?
o Relative to the milky way, the planets move, but stars are in constant position
o Planets move relative to the majority of the stars
Gravity
• Newton’s Gravitational Law: a sun ms separated by planet mp by distance r
o Force = G(msmp/r2)
§ G is the gravity constant
• The force causes the planet to move according to Newton’s second law:
o Fp = mpap
o ap is independent of the mass of the planet (mp)
• Why is the mass the same in both of Newton’s equations?
o This is the origin of Einstein’s theory
Document Summary
Introduction: professor: r. brandenherger rhb@physics. mcgill. ca, tas: m. anthonisen, y. tsiares, website: physics. mcgill. ca, textbook: cosmic perspective, grading format, final 30, midterms (2) 30% total. Nov. 14: homework 30, report 10, our place in the universe. What came before: explain observed large scale structures, patterns in the distribution of galazies on large scales, anistotrophies in cmb maps, make predictions for future observations. Gravity: newton"s gravitational law: a sun ms separated by planet mp by distance r, force = g(msmp/r2) 3: once we know the distance of the planet, we can estimate the size. This is the maximal speed (nothing travels faster: astronomical unit of distance: light year (lyr) The distance light travels in 1 year ~ 9. 5 x 1012 km: 1 parsec (pc) ~ 3. 26 lyr. 1kpc = 103 pc, mpc = 106pc etc. Note: billion and trillion are not universal, do not use these terms, always refer by power of 10.
