Reflection

To construct a reflection diagram, draw the surface and an incident ray pointing towards it. At the point where the ray meets the surface, draw a dashed normal at 90° to the surface. Draw the reflected ray pointing away on the other side of the normal.

Some of its energy may return, some may pass into the second material, and some may be taken up by the material. These effects are called reflection, transmission and absorption. A wave that passes into the second material may also be refracted.

You may see a faint reflection in the glass, while most of the light passes through so that you can see outside. A small amount is absorbed by the glass. The proportions depend on the materials and the surface; absorption does not mean that energy has disappeared.