Light is a very strange phenomenon. It is difficult to classify using our current ideas about the world because it seems to be schizophrenic in its nature. At times it acts like a wave; in other circumstances it acts like a particle. This dual nature can be difficult to understand for students who are at a concrete stage in their thinking. This curriculum unit is designed to make the absorption of these somewhat complex ideas easier. The curriculum unit is written to be taught in a high school physics class; however, most of the ideas could be adapted for use in a middle school or a general science class. Many of the students for whom this unit is intended struggle with basic algebra and read, write and think at about an 8th or 9th grade level. Most of these students have had very little background in science of any kind, so there will be a fair amount of basic and introductory information covered in this unit as well as some of the more advanced topics.
Light is a very important tool in many scientific pursuits. It is, however, essential in the study of astronomy. Astronomical distances are so large that humans have only traveled to our closest astronomical body, our own moon. We have been able to travel via robot to several close astronomical objects in our own solar system, but even those journeys require years of travel. As a result, most of what we know of the universe comes from the study of light emanating from, or reflected by, distant bodies. Thus, to understand the study of astronomical bodies, a sound understanding of light is essential.
This unit will begin with the basic concepts of light, its nature, anatomy and composition. Then, the information we derive from distant light sources will be discussed. Finally, the unit will conclude with a piece on how light is used to make our lives better.