Chapter 3 Quiz Allison Thompson

1. How did Copernicus, Tycho, and Kepler challenge the Earth centered model?
            - Copernicus proposed the sun was the center.
         - He used the model to determine the layout of the solar system.
         - The model was no more accurate than Ptolemaic model in prediction planetary position because it still used perfect circles.
         - Brahe compiled most accurate naked eye measurements ever made of planetary position.
         - Still could not detect stellar parallax and thus still thought earth is center of solar system.
         - Hired Kepler who used Tycho's observations to discover the truth about planetary motion.
         -Kepler first tried Tycho's observation with circular orbits.
         - But 8 arcminute discrepancy led him eventually to ellipses.
  
2.What are Kepler's three laws of planetary motion?
  1) Orbit of each planet around the sun is an ellipse with sun at one focus.
 2) As a planet moves around its orbit, it sweeps out equally in time/ area (faster near the sun, slower when away).
3) More distant planets orbit at slower average speed obeying the realtionship. (p^2=a^3)
                                       p= orbited period in years
                                       a= average distance from sun in AU

3.How did Galileo solidify the Copernican revolution?
      - Earth could not be moving because objects would be left behind.
     - Non-circular orbits are not perfect as heaven should be.
     - If earth was really orbiting the sun we'd detect stellar parallax.

4.How can we distinguish science from nonscience?
     - Defining science can be surprisingly difficult.
     - Science comes from Latin "knowledge" 
     - Not all knowledge comes from science.

 5.What is a scientific theory?
  - Theory has a different meaning in science than everyday life.
    - In science theory is NOT the same as Hypothesis
             - Explain a wide variety  of observations with a few simple principles.
   - Be supported by a large compelling body of evidence.
   - Not failed crucial test of validation. 

6.What does the universe look like from Earth?
    - The universe has 2000 stars along with 88 constellations that can be seen throughout the different seasons of the year.

7. Why was planetary motion so hard to explain?
 - Because the planets drift making it hard explain.

8.Why did the ancient Greeks reject the real explanation for planetary motion?
 - Because it was wrong to be believe that the sun revolved around the earth.

9.In what ways do all humans use scientific thinking?
 - Scientific thinking is based on everyday ideas of observation and trial and error experiments.

10.How did astronomical observations benefit ancient societies?
 - Keeps track of time/season.
    - Practical purpose (agriculture)
    - Religious/Ceremonial Purpose.
    - In aiding navigation.
    - Ancient people of central Africa could predict seasons by the orientation of crescent moon.
    - Days of the week come from planets.