Physics lab groups finagle with laser lights to determine the critical angle of refraction for both water and Lucite. Because there are no detailed steps or an answer key for this enlightening exercise, an inexperienced physics instructor may be most comfortable assigning it. Also, because there is no lab sheet, learners must plan their own procedure and write a complete lab report. Do not discount this resource however; it offers outstanding teaching tips, a simple grading rubric, and embedded links to accompanying reading material for your class.