ASTR 3 Chapter Notes - Chapter 1-1: Semi-Major And Semi-Minor Axes, Ecliptic, Uraniborg
Document Summary
Galileo galilei built a telescope and discovered the moon has mountains, valleys, and craters just like earth, sun has imperfections known as sunspots and inferred sun rotates once per month around axis perpendicular to ecliptic plane. Four small points of light orbit planet jupiter, they were moons. Venus showed complete cycle of phases, just like moon, so it must orbit the sun. All these observations contradicted accepted beliefs of the day. After publishing his beliefs, galileo was instructed to stop and recant. But he continued his experiments, so he was forced to recant and placed under house arrest. Objectivity eventually prevailed: checking, confirming, and refining experimental tests 3 centuries after copernicus proved that the heliocentric model is indeed true. Tycho brahe had an observatory called uraniborg in denmark where he used instruments of his own design and maintained accurtate records of the stars, planets, celestial events. Brahe then moved to prague where he employed johannes kepler.
