How are spectra and color related?
The mix of photon colors that reach our eyes determines what colors we see. We'll learn how to follow a source of light along its path to our eyes and consider how its spectrum relates to the color we see.How We See
Slideshow. This slideshow can be reviewed as a class discussion, in small groups, or on your own, as instructed by your teacher.
- Slides 1-3: Review the four key behaviors of light: emission, absorption, transmission, and reflection.
- Slide 4: Discuss as a class or group, or consider what is happening that allows the person to see the tree depicted. What is emitting the light in the image? How does the light emitted interact with the tree before coming to the person's eye?
- Slide 5: Discuss as a class or group, or consider how the blue car will appear if we shine only a yellow light on it on a moonless night.
- Slide 6: Review the steps for following the path of light that determines what we see. For any given scenario, you will want to ask yourself the questions listed in order to trace the entire path of light.
Spectrum Notebook. For each of the scenarios, imagine tracing the path of light from a source to our eyes. Describe how the light is behaving and how that leads us to see the color that we do.
- You are outside during the day, looking at a green tree. What allows you to see the tree, and why does it appear green? (Depicted in Slide 4.)
- You come out of a shopping mall on a moonless night and look at your car. Your car is painted blue, and the light illuminating the car is yellow. What color does your car appear to you in the yellow light? (Depicted in Slide 5.)
- A red and white candy cane is in a green glass jar. A white light bulb shines on the jar. What do you see, and what processes are making that happen? Be sure to describe separately what both the white and red parts of the candy cane look like when the candy cane is in the green glass jar. (Not depicted in Slideshow.)
