Lesson Plan - Get It!
Imagine you live in a world without color, and you see life like an old black-and-white television show.
- Where has the color gone?
- Why can't you see it?
Image by CBS Television, via Wikimedia Commons, is in the public domain.
In the previous Related Lessons, found in the right-hand sidebar, you learned how humans are able to see in color.
To review, write a few sentences explaining why grass is green. When you are finished, have your teacher or parent check your work.
Sunlight, which is white light, shines down on grass. White light is composed of all the colors of the visible spectrum. When sunlight hits the grass, all the colors of the visible spectrum are absorbed except green. Green is reflected off the grass and back to your eyes, causing you to see green.
- Did you explain the answer correctly?
Based on what you know about the way humans see color, predict what causes humans to see black and white. Write your predictions on a separate piece of paper, then show your predictions to your teacher or parent.
Like the way humans perceive all colors, seeing black and white has to do with the way light is absorbed and reflected.
- What is white light made of?
Tell your teacher or parent.
White light is all the colors of the visible spectrum, the part of the electromagnetic spectrum that humans can see. When you see white, it is because all the colors of the visible spectrum are being reflected off the object and back to your eyes, causing you to see white.
When you see black, it is because all the colors of the visible spectrum are being absorbed by the object. When all the colors of the visible spectrum are absorbed by an object, your brain perceives the object as black.
Find one white and one black object in your house or classroom. Show the objects to your teacher or parent and explain why you see them as white and black. Then, move on to the Got It? section to complete an experiment that proves white reflects light and black absorbs light.