# Optical Illusions

Length: Two class periods.

To commemorate Nashville's role in the historic Civil Rights Movement, the Metro Arts Commission approved the selection of artist Walter Hood to create new public art.  His design for Witness Walls utilizes iconic photos of the Civil Rights movement in Nashville to honor the events and the people who created the blueprint for nonviolent protest.  The installation will be located on the west side of the historic Metro Nashville Courthouse, steps away from the historic April 19, 1960 student-led protest.

Through this Physics lesson, students will be able to:

• distinguish the different properties of light
• complete optical labs with appropriate steps
• use different diagrams (such as the Witness Walls) to demonstrate the path of lights with different mirrors
• identify the different meanings of domain specific language in text
• look at the Witness Walls piece and describe the different optical illusions taking place, created by the convex and concave images.

### Standards & Objectives

Learning objectives:

Content standards:

• CLE 3231.4.3 Explore the optics of lenses
• CLE 3231.4.4 Analyze the optics of mirrors

State Performance Indicators:

• SPI.3231.4.5 Identify the properties of light related to reflection, refraction, diffraction, and interference of light waves
• SPI.3231.4.6 Using light ray diagrams, identify the path of light using a convex lens, a concave lens, a plane mirror, a concave mirror and a convex mirror.
Essential and guiding questions:

Assessing questions:

• What are the similarities and differences between concave and convex lenses?
• What is the difference between a lens and a mirror?
• What ability of glass allows us to magnify, or make things larger?
• How do light waves act when they hit a smooth or shiny surface?

• What effect does changing the distance between the lens and the object viewed have on the orientation and size of the image produced using a convex and a concave lens?
• What are some real world examples of the following: concave mirror, convex mirror and concave lens?
• Why do convex and concave mirrors make some images more powerful?

### Lesson Variations

Blooms taxonomy level:
Analyzing
Differentiation suggestions: