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Applied Physics Waves Unit
Chapter 28 (Color) Notes Applied Physics Waves Unit
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The Color Spectrum (28.1) _______________ _______________ was the first to make a systematic study of color. By using a _______________ he showed that sunlight is composed of a mixture of _______________. He called this spread of colors the _______________. The colors were projected in the following order: _______________, _______________, _______________, _______________, _______________, _______________, and _______________. (ROYGBIV) Sunlight is an example of _______________ light. This is a _______________ of all the colors. In white light, _______________ objects appear _______________ and _______________ objects appear in their individual _______________. _______________ is not a color, but a combination of colors. Likewise, _______________ is not a color, but is the _______________ of light. It _______________ light of all visible frequencies. Isaac Newton prism colors spectrum red orange yellow green blue indigo violet white mixture white white colored colors White black absence absorbs
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Color by Reflection (28.2) color
The _______________ of most objects is due to the way they _______________ light. Reflected light is similar to how sound is reflected from a _______________ _______________. They project sound at a set frequency. Likewise, objects’ electrons oscillate at set frequencies, allowing for a particular _______________ to be reflected to us. Other frequencies of light are mostly _______________. Objects that reflect most frequencies (absorbing none) appear _______________. Objects that absorb most frequencies (reflecting none) appear _______________. Most objects do not reflect a single frequency, but a _______________ of frequencies. For example, an object that appears yellow may not just be yellow light, but a combination of _______________ and _______________. Objects can only reflect light frequencies that are present in the _______________. (See Figure 28.5 on p. 424) color reflect tuning fork frequency absorbed white black spread red green source(s)
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Color by Transmission (28.3)
As we discovered in last chapter, _______________ objects allow light to pass through them. This is called _______________. A material in a transparent object that selectively absorbs certain light frequencies is known as a _______________. For example, colored glass absorbs all _______________ except the _______________ observed. (See Figure 28.6 on p. 424) transparent transmission pigment frequencies color
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Sunlight (28.4) _______________ light from the sun is a combination of all visible _______________. The brightness of the frequencies is _______________ though. Our sun has a greater intensity in the _____________ and ____________ regions. (See Figure 28.7 on p. 426) White frequencies uneven yellow green
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Mixing Colored Light (28.5)
______________ of all visible frequencies, when mixed, will produce _______________ light. White also results from the combination of _______________, _______________, and _______________ frequencies of light at equal brightness. Certain colors overlapped will produce the appearance of other _______________. Examples of color mixings include: (See Figure 28.8 on p. 426) Red + Green = Yellow Red + Blue = Magenta (Pinkish Shade) Blue + Green = Cyan (Bluish Green) These can be used to produce the _______________ colors. Red, Blue, and Green are called the _______________ _______________ ___________. Here colors are mixed by _______________. Light white red green blue colors other additive primary colors addition
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Color Addition and Subtraction
Color Addition (light) Color Subtraction (Pigment) Red Cyan Yellow Magenta Green Blue White Black Cyan Yellow Red Magenta Green Blue
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Complimentary Colors (28.6)
Yellow, Magenta, or Cyan can be formed when _______ of the additive primary colors are combined. (Remember that _______ of these colors added will produce __________) When two colors are added to produce __________, these are called _______________ _______________. Examples of these are as follows: (See top of p. 428) Yellow + Blue = White Magenta + Green = White Cyan + Red = White If you begin with _________ light and subtract a single color, then the resulting color will be its _______________. For example, an object that absorbs red light will appear cyan. two three white white complementary colors white compliment
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Mixing Colored Pigments (28.7)
The mixing of _______________ is an entirely different process than the mixing of _______________. The color that the pigment _______________ is the color we see. The color that the pigment _______________ is the color that we do not see. For example, blue paint absorbs red, orange, and yellow; it reflects mostly blue light, but also some violet and green. (See Figure on p. 430) _______________, _______________ , and _______________ are the best colors to use in pigments. Consider computer printers, which use these colors. These are called _______________ _______________ _______________. The reason they are referred to this way is because combinations of colored pigments _______________ more light than that of a single color. (See Table 28.1 on p. 431) pigment light reflects absorbs magenta yellow cyan subtractive primary colors absorb
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Mixing Colored Pigments (28.7)
Absorbs Reflects Red Blue, Green Green Blue, Red Blue Red, Green Yellow Cyan Magenta
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Why the Sky Is Blue (28.8) A tuning fork set into motion will redirect _______________ in all directions. Similarly, the _______________ scatters light as it comes to the earth from the sun. The atmosphere scatters _______________ frequencies better than _______________ frequencies. Thus, we see _______________, which is a _______________ frequency. If there is dust or other particles present, then the sky will appear less _______________ because more _______________ frequency light is scattered. _______________ appear white because of the varying sizes of _______________ droplets, which scatter frequencies evenly. sound atmosphere higher lower blue high blue high Clouds water
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Why Sunsets Are Red (28.9) _______________ frequencies are scattered least by our atmosphere. As the sun gets lower in the sky, the light has more _______________ to pass through. Thus, only the _______________ frequencies reach an observer for the most part. (See Figure on p. 434) Lower atmosphere lower
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Why Water is Greenish Blue (28.10)
Water is a good absorber of _______________ and _______________ frequencies. As a result (through color subtraction) the water appears greenish-blue or _______________. Many animals, such as _______________ are red so that they will appear _______________ underwater. This is an excellent source of camouflage. infrared red cyan crabs black
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The Atomic Color Code – Atomic Spectra (28.11)
Every _______________ has its own characteristic set of colors when made to emit light. (For example, iron will emit different colors than copper when heated) The glow of any _______________ is different from any other _______________. The light from glowing elements can be analyzed by a device called a _______________. Individual glowing elements produce sets of glowing lines, which are different _______________. This is not a continuous band of color. (See figure on p. 438) element element element spectroscope frequencies
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American Flag Example Stare at the American flag for about 1 minute.
Then look at the white box to the right. What do you see in the box?
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