2020-09-26

Reasoning
- Evidential
  - Giving real evidence for certain reasoning
- Pragmatic
  - Giving no evidence for certain reasoning

Low signal is 0
High signal is 1
Three methods for describing the behaviour of logic gates and circuits
- Boolean expressions (boolean algebra)
- Logic diagrams
- Truth tables

Chapter 4.1: Earth and Sky
- Learning objectives:
  - Describe how latitude and longitude are used to map Earth
  - Explain how right ascension and declination are used to map the sky
Chapter 4.2: The Seasons
- Learning objectives:
  - Describe how the tilt of Earth’s axis causes the seasons
  - Explain how seasonal differences on Earth vary with latitude
Chapter 4.3: Keeping Time
- Learning objectives:
  - Explain the difference between the solar day and the sidereal day
  - Explain mean solar time and the reason for time zones
Chapter 4.5: Phases and Motions of the Moon
- Learning objectives:
  - Explain the cause of the lunar phases
  - Understand how the Moon rotates and revolves around Earth
Chapter 4.6: Ocean Tides and the Moon
- Learning objectives:
  - Describe what causes tides on Earth
  - Explain why the amplitude of tides changes during the course of a month
Chapter 4.7: Eclipses of the Sun and the Moon
- Learning objectives:
  - Describe what causes lunar and solar eclipses
  - Differentiate between a total and partial solar eclipse
  - Explain why lunar eclipses are much more common than solar eclipses
- The Sun and the Moon have the same angular size (0.5˚)
  - The Sun is 400x larger in diameter than the Moon
  - The Sun is also 400x farther away