Author Archive
A Peek Into My Class Notes: PHY 121 – 1st Semester Descriptive Astronomy
by Merv Burger on Sep.23, 2009, under General
Ptolemy’s Geocentric Model (AD 140): was the accepted model of the universe until the Copernican Revolution
Copernicus didn’t like Ptolemy’s model because the planets had to move along complex paths called epicycles in order to explain retrograde. He realized that a heliocentric model could also explain retrograde.
In the heliocentric model, the retrograde motion occurs naturally as Earth passes a planet. It made epicycles unnecessary, and was more appealing as a scientific model. It was still inaccurate, but was closer to being correct.
Tycho Brahe: his contribution was the use of sighting instruments for precise celestial observations, reported in detailed tables. His tables were later used by Kepler to develop the 3 laws of planet motion.
His model was a “hybrid” model, the sun moon and stars revolved around the Earth, however, the rest of the planets revolved around the sun.
Brahe was also an arrogant motherfucker that didn’t fuck around. He got into a duel that took off the tip of his nose, so he got the thing replaced with fucking gold. He eventually went out in the most badass way ever, by eating and drinking himself to death. He decided to show that peon Kepler some mercy and allowed him to have his tables before dying.
Johannes Kepler: Armed to the teeth with Astronomical Tables of Brahe ™ , he studied the motion of the planets mathematically.
He found a model that predicted the position of the planets far into the future by abandoning both the geocentric universe and the uniform circular motion ideas.
Kepler’s Model was:
- Heliocentric: all the planets move around the sun
- Planets travel elliptical paths with non-uniform velocities
- Predicts the position of planets as a function of time using simple mathematical laws
Story of my fucking life…
by Merv Burger on May.17, 2009, under General
Only I could go clubbing with two girls and not be dating anyone.
Yep.




