AST101H5 Lecture Notes - Lecture 5: Semi-Major And Semi-Minor Axes, Nicolaus Copernicus, Deferent And Epicycle
Document Summary
Every ancient culture observed the night sky and tried to understand it. Ancient greek astronomers established the foundation of modern astronomy by. Aristotle argued that earth is really a huge sphere. The part we see is so small that it looks flat. Merchants travelling from greece to other regions reported seeing new stars or not being able to see familiar stars. This isn"t possible if the earth is flat. Note: relative distance is like a ratio. He used numbers to assist his thinking - essential for science. At the moon"s 1st and 3rd quarter phase we see half of the moon"s day side = angle between earth-moon-sun is exactly 90 degrees. Measuring the angle between the earth and the moon between the direction to the moon and the direction to the sun sets up a triangle. Drawing the triangle to scale, his measured the relative distances of the moon and the sun.
