Students predict gnomon results at various localities. Students are encouraged to observe circumpolar constellations. Models of Tilting Activity 1 Consideration of three different explanations for observations to date. Few students will have ever questioned the standard model for the earth-sun relationship. The Strength of a Model Reading Selection 0.5 Motions of circumpolar constellations provide further evidence.
Students apply their personal observations to the problem at hand.
Relative Motion Reading Selection 0.5 Provides background. The assumption is made that students will not yet be conversant with Newtonian mechanics. Refining a Model Activity 0.5 Seeking a model which satisfies all observations to date. The value of the selected model will lie in its compliance with the largest number of observations. Meteor frequencies may be more so, and certainly more accessible.