If you can see through a material, but the objects you see through it do not look clear or distinct, then the material is translucent (trans LOO sunt). A translucent material scatters light. The soaps in Figure 17A are translucent. When you look into a room through a frosted glass door, you can make out shapes of people and objects, but the shapes are fuzzy and lack detail.
Figure 17 When light strikes a new medium, it can be reflected, absorbed, refracted, polarized, or scattered. A The translucent bars of soap scatter light, making the soaps and what you can see through them appear fuzzy. B You cannot see through the fruit because opaque materials do not transmit any light.
Most materials are opaque (oh PAYK). An opaque material either absorbs or reflects all of the light that strikes it. The fruit in Figure 17B is opaque. An opaque object does not allow any light to pass through it. You can't see through a wooden table or a metal desk. Wood and metal are examples of opaque materials.
Interactions of Light
When light encounters matter, some or all of the energy in the light can be transferred to the matter. And just as light can affect matter, matter can affect light. 
When light strikes a new medium, the light can be reflected, absorbed, or transmitted. When light is transmitted, it can be refracted, polarized, or scattered.
Reflection
When you look in a mirror, you see a clear image of yourself. An image is a copy of an object formed by reflected (or refracted) waves of light. Similarly, when you look at a still lake, you can see a sharp reflected image of the far shore. But what happens to the reflected image in the lake if the wind suddenly gusts, causing ripples in the surface of the water? The image is blurred, or fuzzy-looking. When light reflects from a smooth surface, you see a clear, sharp image. When light reflects from a rough surface, you see a blurred reflected image or no image at all.
Regular reflection occurs when parallel light waves strike a surface and reflect all in the same direction. Regular reflection happens when light hits a smooth, polished surface, like a mirror or the surface of a still body of water such as in Figure 18.
Diffuse reflection occurs when parallel light waves strike a rough, uneven surface, and reflect in many different directions. If you could look at this page of your book through a microscope, you would see that the paper has a rough surface. The rough surface causes diffuse reflection of the light that shines on it.
Figure 18 Almost all objects reflect light. A In regular reflection, a smooth surface reflects a clear image because parallel light waves reflect all in the same direction. B In diffuse reflection, parallel light waves reflect in many directions.
Table of Contents