Summarizing Some Key Astronomy Historical Ideas s1

Summarizing some Key Astronomy Historical Ideas

Cavepeople: looking at the night time sky, grunting

Greeks: Earth at the center of the universe. Motion in the sky follows perfect harmony. Objects in the sky follow perfect circular motions at constant speed. Materials in the sky were different than those on earth.

Ptolemy: Used the ancient greek ideas but tried to develop a more accurate geometry to describe the motions of the “wanderers. Created the geometry using epicycles to account for the strange motion of Mars & other wanderers.

Copernicus: Believed that a simpler model could be created by moving the Sun to the center of the universe. Still used epicycles, but his model was much simpler than Ptolemy’s. His sun-centered system not widely accepted, especially by the church and religious leaders Tycho Brahe: Built an astronomy center and collected data which was much more accurate than any other prior data. Data used by Kepler

Johannes Kepler Used Tycho’s data to plot the orbit of Mars and other “wanderers” Found that Mars’ orbit is actually elliptical, not circular Mar’s speed changes as it moves in orbit. Developed 3 laws which to this day are still valid. Believed in Copernicus model and that there must be some action that is causing Orbital motions.

Galileo Law of falling bodies, all objects on earth fall with acceleration g = 10 m/s/s Developed many of the ideas of mechanics, experiments on earth. Strongly believed in Copernicus idea of a heliocentric model of the universe, went To “jail” for this .

Newton Developed laws of motion Made a connection between the motion of the moon and the falling apple on the Earth. Developed the idea of Universal Gravitation, the reason the moon moves in an orbit is the same reason the apple falls on the earth. Ties the same rules on earth to those in the heavens. Generally believed to be one of the greatest scientists ever, if not the biggest.