As you sight at the portion of the pencil that is submerged in the water, light travels from water to air (or from water to glass to air). Light waves can travel through objects like air, water, oil, and glass, but not through a pencil itself. Refraction is a physics concept that refers to how a wave travels through a medium. It appears as if the pencil is broken, but it is just because of the refraction of light. Pencil in water glass. 3. Above the water, the light reflects from the straw through the air and glass to your eyes. The light from the pencil is refracted as it passes from the water to the glass to air, causing it to be displaced. A light wave travels through a medium using a process known as refraction. Illustration about Refraction. Look at the pencil from the side. Play this game to review Optics. https://ezscience4kids.blogspot.com/2011/05/bending-pencil.html As you look at the portion of the pencil that is submerged in the water, light travels from water to glass to air. The reciprocal action between the molecules of reflexion and t iii r»jiii i«i t refraction of various substances and those ot the ether which pervades ]i