Light Properties
Because of light, we can see color and reflections. A portable glucose meter is one example of medical devices that use color changes to detect body chemicals.Copyright 2004 (top) Microsoft Corporation, One Microsoft Way, Redmond, WA 98052-6399 USA. All rights reserved. (bottom) US Food and Drug Administration http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm276191.htm
Students learn about the basic properties of light and how light interacts with objects. They are introduced to the additive and subtractive color systems, and the phenomena of refraction. Students further explore the differences between the additive and subtractive color systems via predictions, observations and analysis during three demonstrations. These topics help students gain a better understanding of how light is connected to color, bringing them closer to answering an overarching engineering challenge question.
A deep understanding and exploration of the properties of light has enabled engineers and scientists to illuminate our world with everything from computer monitors, TV screens, and lasers to fiber optic cables and medical devices. For example, fiber optic cables give us the ability to communicate and transmit data over long distances at high rates by guiding light through refraction. Since first demonstrated in the 1840s, engineers and scientists have adapted fiber optics to many applications, including communication and medical imaging. Portable glucose monitors are one example of medical devices that use color change as a way to detect body chemicals. With this device, a diabetes patient can independently monitor his/her glucose levels, greatly increasing his/her quality of life. Before designing a solution to a challenge, engineers conduct research and gather information as a key step in the engineering design process. Through this legacy cycle lesson, students continue to gather the knowledge necessary to devise solutions to the engineering challenge outlined in lesson 1 of this unit.
After this lesson, students should be able to:
- Explain how objects appear to be a certain color.
- Explain how monitors and TVs display color.
- Describe opaque, translucent and transparent objects.
- Identify additive and subtractive color phenomena.
- Explain the difference between additive and subtractive color.