Refraction close refractionProcess by which a wave changes speed and sometimes direction upon entering a denser or less dense medium, eg a light ray changes direction when refracted by a lens. of ...

Reflection Reflections from flat surfaces are fairly easy to understand. A reflection appears to be the same distance from the "other side" of the mirror as the viewer's eyes are from the mirror. Also ...

Introduction Can you imagine a bouncy ball that could bounce back and forth between two walls, infinitely—that is, forever? Wouldn't that be amazing? What if, instead of a ball, light was bouncing ...