ASTRO 101 Lecture Notes - Lecture 3: Solar Calendar, Lunar Phase, Water Clock
Document Summary
Benefits of astronomy: timekeeping track seasonal changes, navigation. Night - position and phase of the moon. 3 philosophical innovation: tradition of understanding nature without relying on supernatural explanation and of working communally to debate and change ideas, use mathematics to give precision - explore implications of new ideas, reasoning from observation. Model: conceptual representation -> explain & predict observed phenomenon (ex: Geocentric model: place a spherical earth at the center of the universe. Thales - water & flat disk floating in ocean. Anaximander - empty space & surrounded by stars, sun, moon rings. Aristotle - gravity pull things together - form spherical earth. Ptolemaic model - adapt & synthesize earlier ideas into a single system. Kepler: planetary orbits like ellipse (foci & semimajor axis) Eccentricity: describe how much an ellipse is stretched out. Kepler"s laws of planetary motion: orbit of each planet about the sun is an ellipse with the sun at one focus.