Lecture Description
Topic: Saros Cycle
Next: Lesson 2 (www.youtube.com/playlist?list=PLE25EA806E9A420B2)
Previous: Eclipse Seasons (youtu.be/kh7VljWmcUM)
In Lesson 1, we explore the apparent motions of the stars, the sun, and the moon. We 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 learn how length of day and the height of the sun in the sky at midday vary with season and latitude. We explore lunar phases, lunar and solar eclipses, and the cycle over which all eclipses repeat.
Course Index
- Size and Scale
- Constellations and the Celestial Sphere
- Motion of the Celestial Sphere
- Sun-Earth-Moon Scale Model
- Solar vs. Sidereal Time
- Seasons
- Precession
- Lunar Phases
- Lunar Month
- Eclipses
- Eclipse Seasons
- Saros Cycle
- Stonehenge
- Geocentric Models
- Heliocentric Models
- Galilean Revolution
- Aberration of Starlight and Stellar Parallax
- Tycho and Kepler
- Kepler's Laws of Planetary Motion
- Measuring the Astronomical Unit
- Newton's Laws of Motion
- Newton's Law of Universal Gravitation
- Derivation of Kepler's Laws from Newton's Laws
- Light, Cosmic Rays, Neutrinos, and Gravitational Waves
- Particle vs. Wave Motion
- Diffraction, Interference, and Polarization
- Electromagnetic Spectrum
- Light and the Electromagnetic Field
- Thermal Radiation
- Why Are There No Green Stars?
- Spectroscopy and Kirchhoff's Laws
- Atomic Structure
- Hydrogen Spectral Series
- Kirchhoff's Laws Explained
- Doppler Effect
- Spectral Line Widths
- Basic Reflecting Telescope
- Basic Refracting Telescope
- Reflecting vs. Refracting Telescopes
- Reflecting Telescope Designs
- Detectors
- Spectrographs
- Light-Gathering Power
- Resolving Power
- Atmospheric Blurring
- High-Resolution Observing
- University of North Carolina's Telescopes
- Jansky and Reber
- Radio Telescopes
- Radio Interferometers
- Introduction to Radio Astronomy
- Space-Based Telescopes
Course Description
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.