Understand That We Need Light to See Color

Lesson Plan: February 27, 2006

1. understand that we need light to see color.
2. understand that we need light and a clear substance (i.e. water) to see the visible light spectrum.
3. understand the physical process of sight.
4. create and understand the visible light spectrum and the process of “slowing down” light enough to see the colors it contains.

1. light shining through clear plastic cups filled with water, both clear and colored.

1. begin the lesson by, first warning the students, then asking Dr. Irons to turn off the lights.
2. ask the students, “What color is my shirt?”
3. explain that we need light to see color.
4. connect the reading from Chapter 1 by informing students that we have special structures in our eyes called cones that enable us to see the colors around us; the cones the send the color message to our brain.
5. explain that we need light and a clear material such as water, plastic, or glass to see the visible color spectrum and that our experiment today will prove that.
6. instruct students to get into pairs and pass out all necessary supplies.
7. instruct students to fill up three plastic cups with water.
8. instruct students to fold the provided piece of paper in half, “hamburger” style.
9. instruct students to, carefully, place one cup of water very close the edge of their table and place the paper behind it.
10. instruct students to shine their flashlight at an angle into the cup of water after asking Dr. Irons to turn of the lights again.
11. allow time for students to manipulate the light and “find” the visible light spectrum.
12. ask students what colors they can see and why they think they can see them.
13. inform students that a spectrum is made when white light traveling through the air is slowed down by going through a clear material, such as plastic and water; the slowing down causes the white light to break into the colors of the spectrum; red light is slowed the least and violet light is slowed the most.
14. ask students if they know the acronym – Roy G. Biv.
15. add food coloring to the remaining full cups of water and instruct students to repeat the process with the cups of colored water.
16. ask students what colors they can see with the colored water.
17. ask student what this means and allow time for thoughtful discussion.
18. ask students to clean up their work space and return all provided materials.