1. 14.4 color and polarization
Recognize how additive colors affect the color of light
Recognize how pigments affected the color of reflected light.
Explain how linearly polarized light is formed and detected.

2. Color
The interaction of sunlight with matter can result in one of three wave behaviors: ____________________________________
__________________________________________________.
The color of the objects that we see are largely due to the way those objects reflect or transmit the light to our eyes. The color of an object is not actually within the object itself. Rather, the color is in the light that shines upon it and is ultimately reflected or transmitted to our eyes.

3. Additive and subtractive primary colors of light
Additive primary colors of light: ___________________
Additive primary colors produce _______________ when combined.

4. Subtractive primary colors of light: ___________________
Subtractive primary colors _________ all light when combined.

5. Blue Skies
The two most common types of matter present in the atmosphere are gaseous nitrogen and oxygen. These particles are most effective in _____________________________ portions of the visible light spectrum such as blue and violet light. This scattering process involves the absorption of a light wave by an atom followed by reemission of a light wave in a variety of directions.
All high frequency light are scattered. However, our eyes are more sensitive to light with blue frequencies. Thus, we view the skies as being blue in color.

6. What Makes a Red Sunset? There are two reasons:
As the Sun gets lower in the sky, its light is passing through more of the atmosphere to reach you. Even ________________________________, allowing the reds and yellows to pass straight through to your eyes.
The sky appears red because ________
______________________, pollution, and water vapor in the atmosphere reflect and scatter more of the reds and yellows.

7. Polarization of light waves
Light is a transverse wave that vibrate in ________________planes. A light wave which is vibrating in more than one plane is referred to as ______________________light.

8. Light can be polarized
Polarized light waves are light waves in which the vibrations occur in __________________________.
The most common method of polarization involves the use of a Polaroid filter. Polaroid filters are made of a special material which is capable of blocking one of the two planes of vibration of an electromagnetic wave. When unpolarized light is transmitted through a Polaroid filter, it emerges with one-half the intensity and with vibrations in a single plane; it emerges as polarized light.

10. Note: a longitudinal wave ____________ be polarized
Note: a longitudinal wave ____________ be polarized. ___________ wave is a longitudinal wave, sound wave _________________________________.

11. Applications of Polarization
Used in ______________________________________.
Light reflected from surfaces such as a flat road or smooth water is generally horizontally polarized. This creates an annoying and sometimes dangerous intensity of light that we experience as glare.
Polarized lenses contain a special filter that blocks this type of intense reflected light, reducing glare.

13. ..\..\RealPlayer Downloads\Polarized 3-D Glasses.flv
Polarization is also used in the entertainment industry to produce and show ___________________. Three-dimensional movies are actually two movies being shown at the same time through two projectors.
movies are actually two movies being shown at the same time through two projectors. The two movies are filmed from two slightly different camera locations. Each individual movie is then projected from different sides of the audience onto a metal screen. The movies are projected through a polarizing filter. The polarizing filter used for the projector on the left may have its polarization axis aligned horizontally while the polarizing filter used for the projector on the right would have its polarization axis aligned vertically. Consequently, there are two slightly different movies being projected onto a screen. Each movie is cast by light which is polarized with an orientation perpendicular to the other movie. The audience then wears glasses which have two Polaroid filters. Each filter has a different polarization axis - one is horizontal and the other is vertical. The result of this arrangement of projectors and filters is that the left eye sees the movie which is projected from the right projector while the right eye sees the movie which is projected from the left projector. This gives the viewer a perception of depth.
Our model of the polarization of light provides some substantial support for the wavelike nature of light. It would be extremely difficult to explain polarization phenomenon using a particle view of light. Polarization would only occur with a transverse wave. For this reason, polarization is one more reason why scientists believe that light exhibits wavelike behavior.
It is possible to transform unpolarized light into polarized light. Polarized light waves are light waves in which the vibrations occur in a single plane. The process of transforming unpolarized light into polarized light is known as polarization. There are a variety of methods of polarizing light. The four methods discussed on this page are The most common method of polarization involves the use of a Polaroid filter. Polaroid filters are made of a special material which is capable of blocking one of the two planes of vibration of an electromagnetic wave. (Remember, the notion of two planes or directions of vibration is merely a simplification which helps us to visualize the wavelike nature of the electromagnetic wave.) In this sense, a Polaroid serves as a device which filters out one-half of the vibrations upon transmission of the light through the filter. When unpolarized light is transmitted through a Polaroid filter, it emerges with one-half the intensity and with vibrations in a single plane; it emerges as polarized light.
..\..\RealPlayer Downloads\Polarized 3-D Glasses.flv
14.4 Color and Polarization

14. Class work – today’s date
Sunlight is composed of various intensities of all frequencies of visible light. The graph represents the relationship between light intensity and frequency. Based on the graph, which color of visible light has the lowest intensity?
violet
red
blue
yellow
green
orange

15. It has been suggested that fire trucks be painted yellow green instead of red. Based on the information from the graph, which is the best explanation of the advantage of using yellow-green paint instead of red?
Yellow green is brighter than red.
Red has a higher frequency than yellow green.
Yellow green has a lower intensity than red.
The brightness of the colors is proportional to their frequencies

16. As the color of light changes from red to yellow, the frequency of the light
decreases
increases
remains the same
The diagram shows a beam of light entering and leaving a "black box."  The box most likely contains a
prism
converging lens
double slit
polarizer

17. Which phenomenon does not occur when a sound wave reaches the boundary between air and a steel block?
reflection
refraction
polarization
absorption
The diagram shows sunglasses being used to eliminate glare. Which phenomenon is being represented in the diagram?
dispersion
diffraction
internal reflection
polarization

18. A house is painted with pigments that reflect red and blue light but absorb all other colors.
What color does the house appear to be when it is illuminated by white light?
What color does it appear to be under green light