14.4 color and polarization

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14.4 color and polarization

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

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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.

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Additive and subtractive primary colors of light
Additive primary colors of light
___________________
Additive primary colors produce _______________
when combined.
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Subtractive primary colors of light
___________________
Subtractive primary colors _________ all light
when combined.
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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.

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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.

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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.

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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.

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

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• 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.

..\..\RealPlayer Downloads\Polarized 3-D
Glasses.flv
14
Class work todays 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

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• 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

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• 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

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• 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

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• 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