Topic: Geocentric Models

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In Lesson 2, we explore the apparent motions of the planets, as well as attempts to explain these motions throughout history. Specifically, we explore the geocentric models of Aristotle and Ptolemy and the heliocentric models Aristarchus, Copernicus, and Kepler, culminating in Kepler's three laws of planetary motion. We explore tests of these models by Galileo and others. Finally, we learn how Newton explained Kepler's empirical laws with physical law and universal law. But we begin by exploring Stonehenge as an example pre-written-history astronomy, or archaeoastronomy.

1. Size and Scale
2. Constellations and the Celestial Sphere
3. Motion of the Celestial Sphere
4. Sun-Earth-Moon Scale Model
5. Solar vs. Sidereal Time
6. Seasons
7. Precession
8. Lunar Phases
9. Lunar Month
10. Eclipses
11. Eclipse Seasons
12. Saros Cycle
13. Stonehenge
14. Geocentric Models
15. Heliocentric Models
16. Galilean Revolution
17. Aberration of Starlight and Stellar Parallax
18. Tycho and Kepler
19. Kepler's Laws of Planetary Motion
20. Measuring the Astronomical Unit
21. Newton's Laws of Motion
22. Newton's Law of Universal Gravitation
23. Derivation of Kepler's Laws from Newton's Laws
24. Light, Cosmic Rays, Neutrinos, and Gravitational Waves
25. Particle vs. Wave Motion
26. Diffraction, Interference, and Polarization
27. Electromagnetic Spectrum
28. Light and the Electromagnetic Field
29. Thermal Radiation
30. Why Are There No Green Stars?
31. Spectroscopy and Kirchhoff's Laws
32. Atomic Structure
33. Hydrogen Spectral Series
34. Kirchhoff's Laws Explained
35. Doppler Effect
36. Spectral Line Widths
37. Basic Reflecting Telescope
38. Basic Refracting Telescope
39. Reflecting vs. Refracting Telescopes
40. Reflecting Telescope Designs
41. Detectors
42. Spectrographs
43. Light-Gathering Power
44. Resolving Power
45. Atmospheric Blurring
46. High-Resolution Observing
47. University of North Carolina's Telescopes
48. Jansky and Reber
49. Radio Telescopes
50. Radio Interferometers
51. Introduction to Radio Astronomy
52. Space-Based Telescopes

In Lesson 1, we will explore the apparent motions of the stars, the sun, and the moon. We will explain the apparent motions of the stars and the sun in terms of the motions of Earth: its daily spin on its axis, its annual orbit around the sun, and the long-term precession of its spin axis. We will learn how length of day and the height of the sun in the sky at midday vary with season and latitude. We will explore lunar phases, lunar and solar eclipses, and the cycle over which all eclipses repeat.

In Lesson 2, we explore the apparent motions of the planets, as well as attempts to explain these motions throughout history. Specifically, we explore the geocentric models of Aristotle and Ptolemy and the heliocentric models Aristarchus, Copernicus, and Kepler, culminating in Kepler's three laws of planetary motion. We explore tests of these models by Galileo and others. Finally, we learn how Newton explained Kepler's empirical laws with physical law and universal law. But we begin by exploring Stonehenge as an example pre-written-history astronomy, or archaeoastronomy.

In Lesson 3, we explore how we receive information from the universe, primarily in the form of light. We explore the nature of light, beginning with whether it is a particle or a wave. If it is a wave, what is the medium in which the wave travels? We explore how light is created, and study two examples in detail: thermal radiation and atomic absorption and emission lines. We study the absorption and emission lines of hydrogen, the most abundant element in the universe, in particular. We learn how all of this information can be used to measure compositions and temperatures. We explore the Doppler effect and how it can be used to measure line-of-sight velocities, internal motions, etc.

Lesson 4 is focused on the basics of telescopes, how they work, how to set them up, and how to use them.