Quiz

1. How did Copernicus, Tycho, and Kepler challenge the Earth centered model? • proposed Sun-centered model (published 1543) used model to determine layout of solar system (planetary distances in AU).

2. What are Kepler's three laws of planetary motion?

a. The orbit of each planet around the Sun is an ellipse with the Sun at one focus.

b. As a planet moves around its orbit, it sweeps out equal areas in equal times.

c. More distant planets orbit the Sun at slower average speeds, obeying the relationship

3. How did Galileo solidify the Copernican revolution? Earth could not be moving because objects in air would be left behind. Non-circular orbits are not “perfect” as heavens should be. If Earth were really orbiting Sun, we’d detect stellar parallax.

4. How can we distinguish science from nonscience? Science: seeks explanations that rely solely on natural causes; progresses through the creation and testing of models of nature; models must make testable predictions.

5. What is a scientific theory? A model that explains a wide variety of observations in terms of a few general principles and that has survived repeated and varied testing.

6. In what sense is the moon imperfect? The moon is not a perfect circle shape. It has deformities such as craters.

7. Why did Kepler use ellipses instead of circles? The orbit of a planet around the Sun is an ellipse having the center of mass of the planet-Sun system at one focus.

8. When was Tycho Brahe born? December 14, 1546

9. When was Johannes Kepler born? December 27, 1571

10. When was Galileo Galilei born? February 15, 1564