What is shadow?

摘要

This paper has two parts. In the first part, intended for physics students as well as for engineering students whose primary interest is not physics, a new lesson related to shadow properties is given as a part of lectures on light. The effects resulting from a shadow ’motion’ observed on a screen were looked into. The relationship between the parameters that define the screen placement and the parameters related to the conditions of shadow formation is given. The possibility of information transfer in the optimal geometrical conditions is analyzed as well. The second part of the paper contains homework assignments. Assignments designed for physics students differ from those proposed for engineering students. The assignments are intended to encourage students to reason and to take a creative approach.