Light is the basis for many important processes on Earth, and this course is designed to introduce students to many of these fundamental processes. The first third of the course focuses on the nature of light and its interaction with matter. We then turn to the process of vision and how light is detected by humans and animals. The second third focuses on light as an important energy source. We discuss the natural process of photosynthesis and the role that it plays in the global carbon cycle. The role that sunlight plays in the phenomenon of global warming and the effects of global warming will also be explored. We also discuss the artificial capture and harnessing of light energy, as in solar energy. The last part of the course will explore how light interacts with humans directly. Topics to be discussed include how light affects our moods and seasonal affective disorder and the role of light in the onset of melanoma and other UV- light-related health problems. This course provides an introduction to the importance of light in the living world for basic biological processes. Final project for the course will be the generation of a podcast or a Web site on a topic or related topic from the class.