Use of an Umbrella and a Globe to Help Students Understand Apparent Nocturnal Motion
Apparent celestial motion is a common topic which is included in many earth science classes. It is fundamental to understanding the motion of the stars, moon and sun. It is also a topic which quickly becomes confusing to many students. Much of this difficulty arises from problems in spatial imagery and the inability to transfer one's point of view to another location. A careful progression of steps from the development of one's horizon to an understanding of apparent circumpolar motion and even general apparent motion can be accomplished with three-dimensional modeling. In this approach, small groups of students use two simple three-dementional tools, an umbrella and a small globe. In addition, the instructor must carefully monitor and pace the progression of steps or critical concepts can easily be missed.