What you can see Reflected and Transmitted Light

What you can see  You only see light that hits your eye.  You see reflected or transmitted light. You don’t see absorbed light.

Reflection  Specular Reflection- Reflection off a smooth surface, light keeps a similar pattern.  Diffuse Reflection- Reflection off a rough surface, light is scattered. Specular Diffuse

Images  Images are dependent upon the path light can take.  If the light can all take a similar path, an image will be preserved.  If the light is scattered, (sent in all directions) no image will be seen, just light (like when light reflects off you).

Scattering of light  Why is the sky blue?  The gases in the atmosphere scatter blue light (from the sun).  So everywhere you look you see blue light.  Why are sunsets/rises red.  Blue light is scattered when it hits the atmosphere, so by the time most light gets to the extremes the blue is gone.  Red is the other end of the spectrum.

Scattering of sunlight Atmosphere Night side Blue scatters here By the time it gets here all the blue is gone This is not to scale, the sun is larger than the Earth. Clouds and certain gases scatter all light so the sky can appear white sunlight

How much light can get through a material  Transparent- materials that allow most light and a clear image to pass through are transparent.  glass  Translucent- materials that allow some light and no image to pass through.  cloudy plastic  Opaque- materials that allow almost no light to pass through

Depth Perception  Depth perception depends the fact you have 2 eyes  You receive slightly different visions from each eye. (different angles)  Your brain merges them into one 3-D image.  People with loss of sight in one eye lose their depth perception.

3-D effect  If each eye sees a slightly different image, you can create the illusion of depth.  The brain will interpret the two images as one.  For example if the left eye sees the left side of a bee and the right eye sees the right side of the bee, it will appear as though it is right in front of you.  If both eyes see the bee from the same angle it must be further away.

homework  Read section 27.4  Pg 548 questions 11-15, 36, 38-41