LIGHTS, CAMERA, REFRACTION Grade Level: Grade 4 Content Area: Physical Science Core Area: FORMS OF ENERGY – LIGHT AND SOUND Lesson Overview: What is light? Students will investigate and explore ways that light can be reflected, refracted, and diffracted by various objects, and what effect this has on our vision. They will also learn the parts of the eye and how they are specialized for sight. 2005 Standards Correlation: Grade 4 Properties of Light and Electricity Standard 4-5: The student will demonstrate an understanding of the properties of light and electricity (Physical Science). Indicators 5.1 Summarize the basic properties of light (including brightness and colors). 5.2 Illustrate the fact that light, as a form of energy, is made up of many different colors. 5.3 Summarize how light travels and explain what happens when it strikes an object (including reflection, refraction, and absorption). 5.4 Compare how light behaves when it strikes transparent, translucent, and opaque materials. 2014 Standards Correlation: Standard 4.P.4: The student will demonstrate an understanding of the properties of light and sound as forms of energy. 4.P.4A. Conceptual Understanding: Light, as a form of energy, has specific properties including color and brightness. Light travels in a straight line until it strikes an object. The way light reacts when it strikes an object depends on the object’s properties. Performance Indicators: Students who demonstrate this understanding can: 4.P.4A.1 Construct scientific arguments to support the claim that white light is made up of different colors. 4.P.4A.2 Analyze and interpret data from observations and measurements to describe how the apparent brightness of light can vary as a result of the distance and intensity of the light source. 4.P.4A.3 Obtain and communicate information to explain how the visibility of an object is related to light. 4.P.4A.4 Develop and use models to describe how light travels and interacts when it strikes an object (including reflection, refraction, and absorption) using evidence from observations. 4.P.4A.5 Plan and conduct scientific investigations to explain how light behaves when it strikes transparent, translucent, and opaque materials. Copyright © 2015 by the Board of Trustees of the University of South Carolina Page 1 of 2 Materials: Instructor’s Table: • Powerpoint, Eye model, CD, Mirror • Diffraction Glasses Each Student Table (4 students / table; occasionally 5) • Container with: o Beaker, straw and penny (1 per table) o Pencils (1 per student) o Mirrors (1 per student) o CDs (1 per student) o Diffraction Glasses (1 per student) o Copies of eye diagram (1 per student) • Water source Eye Spy Activity: • Shoe Box (1 per group) • Mirrors (4-6 per group) • Clay or mirror stands • Transparent, Translucent and Opaque objects • Targets 7E Procedures for Light lesson: ELICIT § Ask the students, “ Do you see what I see?” § Explain to the students that they can see most everything except their own face. In order to see your own face you will need to look at a reflection of your own face. § Ask the students, “ Has there ever been a time in your life when you could not see as well as you can right now?” § After some responses turn the lights off and see their reaction. § This can lead you into the explanation that you need light and a working eye to see ENGAGE § Have students look at their neighbor’s eyes and make observations of the things they see. (Answers will be parts of the eye, reflections, etc.) § Label the parts of the eye as you discuss each part. EXPLORE § There will be 3 different properties of light to be discussed: Refraction, Reflection and Diffraction. REFRACTION: Show the students an empty beaker with a straw. Ask students to make observations about the differences between the straw inside and outside the beaker. Add some water and repeat. REFLECTION: Have the students look at themselves in the mirror and then turn around and try to read the definition of reflection from the screen. Also have then to pretend to be driving a car and when they look in the “rear view mirror” what do they see. (Ambulance- and it should read correctly in the mirror) DIFFRACTION: Have students try to look at their reflection in a CD. Ask them to explain the differences they see in the CD than in the mirror. Have students look at the lights in the classroom through the diffraction glasses. EXPLAIN § Explain that light is the fastest thing in the universe; it travels at 186,451 mps (11,187,060 mpm, 671,223,600 mph) In comparison sounds travels through air at 343 mps or 767 mph. § Light travels in a straight path from one location to another. § Light can travel through liquid, gas, solid, vacuum (sound does not occur in a vacuum) § Sound needs a medium to travel through, but light does not REFRACTION: Refraction = The bending of light Remind them that they are seeing the straw because light rays from the straw are entering their eye. If they hold the straw in the air, the light rays are traveling only through a gas before reaching your eye. Put the straw in the beaker. The top of the straw is still being seen only through gas, but the bottom part is now being viewed through gas and a solid (the beaker wall). As the light passes from the gas to the solid and back, the light is bent and causes us to see the straw slightly distorted. When water is added, the light rays from the bottom of the straw are now passing through gas, solid, and liquid. The light rays are bent more and cause more distortion. This bending of light as it passes from one material to the next is called refraction. REFLECTION: Reflection = Light bouncing straight back Remind them that light from their faces is striking the mirror and bouncing back into their eyes. Is the reflection exactly correct? Have them grab their right ear. Which ear is their mirror image grabbing? Their left! Objects in mirror appear backwards (mirror image). DIFFRACTION: Diffraction = Breaking light into its parts Each wavelength has a different color – look for them in the CD ROY G BIV - Red, orange, yellow, green, blue, indigo, violet When you see this, you are observing diffraction ELABORATE § Have students complete the “Eye Spy” Engineering Activity to reinforce their knowledge of skills learned. EVALUATE § Give examples of properties of light to see if students can recall terms discussed in the lesson EXTEND § Have students go on a scavenger hunt in the classroom to find instances of Refraction, Reflection and Diffraction. List and describe in their science notebooks. Copyright © 2015 by the Board of Trustees of the University of South Carolina Page 2 of 2 Eye Spy Objective: SC Standards Correlation: The students will use an engineering design challenge to demonstrate an understanding of the properties of light. 4th Grade: Standard 4.P.4 Conceptual Understanding ____________ Performance Indicator ________________________ Materials: • Shoe Box with walls and holes at each end (1 per group) o Walls should be Transparent, Translucent and Opaque • Mirrors (4-6 per group) • Clay or mirror stands • Laser Pointer (1 per group) • Copy Paper (1 sheet per group) Procedure: § Engineering challenge: o Work as a team of secret agents (spy) to send a laser beam through a building (shoe box) that will trigger a device that will disarm your enemy. § The building contains transparent, translucent and opaque walls. § Your secret agent team has managed to infiltrate themselves into the ACME Mirror Company that is currently installing mirrors in this particular building. § You have been paid to install at least 2 mirrors in the building at any location. § The laser beam must hit the target that is outside on the other side of the building. § Encourage students to follow the engineering design process. § Allow enough time for each group to design a solution to the challenge. § Remember there is may be more than one right answer. § Allow groups to test their design with other secret agents.