## The Clockwork Universe (CCU)

**Unit 2: The Cosmic Order and the Clockwork Universe (weeks 4-5)**

**Learning Objectives:**

- Describe the difference between a sun-centered model and an earth-centered.
- List the assumptions and arguments that Copernicus used to support his model and refute the Ptolemaic one.
- Evaluate the strengths and weaknesses of the Copernican model compared to the Ptolemaic one.
- Describe the important geometric properties of ellipses and apply these to planetary orbits.
- State Kepler’s three laws of planetary motion and apply them to appropriate astronomical situations.

**Outline:**

**Heliocentric Solar System Model**

- Copernicus’ model
- Observations made by Tycho Brahe

**Kepler’s Cosmic Harmonies (Basis of orbital mechanics)**

- Law of Ellipses
- Law of equal areas
- Harmonic Law

**Galileo’s Cosmology**

- Classical mechanics
- Observational astronomy with a telescope

**Newton**

- 1
^{st}Law: Law of motion - 2
^{nd}Law: Force Law (F=ma) - 3
^{rd}Law: Reaction Law - Law of Gravity: F= G(m
_{1}m_{2})/r^{2 }and escape velocity: v=SQRT(2GM/r)

**Class Notes**

Read Zeilik: Chapters 3 & 4

Unit 2 Exam Study Guide: Clockwork Universe

- Review all presentations.
- Review the assigned reading: Chapters 3 & 4 in textbook – or – online reading assignment.
- Be able to compare Geocentric and Heliocentric models for our solar system.
- What contributions did Ptolemy, Copernicus, Galileo, Newton, Tycho, and Kepler play in the determining how our solar system works.
- Understand what Newton’s Laws of Motion are and how they pertain to Astronomy.
- Understand what Kepler’s Laws of Planetary Motion and their ramifications.
- Describe Satellite Motion.
- Describe Parallax.
- Calculations for Newton’s 2nd Law, Kepler’s 2nd Law, Newton Law of Gravity, and Escape Velocity.

**Useful websites: **

Online Astronomy: http://astronomyonline.org