If the internal surface material that resembles a cone crop sectors have tended to fall more than one compound and light reflection and external surfaces will affect West and tends to reflect light in the same plane with the internal surface.
If the surface of the material with a conic section has the effect of weight and then the reflection of light incident on the surface is oriented in the same plane and the reflection of light on the inner surface.
If the surface material inside a conic section is the impact of falling more and light reflection surface is the external reflection of incident light, and in the same plane with the surface inside.