X1014308482-00113-26709</DOCNO> The Lengthening of Days Lesson 1: Refraction at a Boundary Boundary Behavior Refraction and Sight The Cause of Refraction Optical Density and Light Speed The Direction of Bending The Secret of the Archer Fish Lesson 2: The Mathematics of Refraction The Angle of Refraction Snell's Law Ray Tracing and Problem-Solving Determination of n Values Lesson 3: Total Internal Reflection Boundary Behavior 