Total Internal Reflection

Total Internal Reflection occurs when light travels from a denser medium (like water or glass) to a less dense medium (like air) at a steep angle. Instead of passing through, the light completely bounces back into the denser medium. This happens when the angle of incidence exceeds a specific critical angle, causing no refraction (bending) into the other medium. It's the principle behind fiber optic cables, where light signals are carried over long distances with minimal loss, by bouncing internally within the glass or plastic fibers.