Mammoth Memory

Rough surfaces

Most surfaces are considered to be rough and reflect light, sending rays in many directions, unlike mirrors. 

 

Light from a torch reflected in a mirror can be seen by an observer at a particular angle:

Observer viewing light from a torch reflected off a mirror

 

Most surfaces are much rougher than a mirror and because of this, they reflect light rays in many different directions. If we magnify a tiny part of a surface, this is what happens to the light that hits it:

Light rays reflected off a rough surface

When we say rough, we mean rough at micro level. Even items that appear smooth, like enamel paint on a pencil, are very rough at micro level.

 

When light is reflected off a rough surface, the light rays are reflected at many different angles. This allows us to to see a surface from any angle.

Light rays reflected off a rough table top surface

Remember, light reflected from an object will spread in many directions.

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