A Stream of Light into the Dark Overview Using simple household materials, campers will learn about electrical circuits and properties to make their very own working flashlight. Topic (s) Grade Level Cost (per class) Time (preparation and activity) Complexity Electrical Engineering, Physics 1-2 $0.09 1 hour Medium Ontario Curriculum Links Understanding Matter and Energy: Grade 1 – Energy in our Lives Big Ideas: Everything that happens is a result of using some form of energy The sun is the principle source of energy for the earth. Humans need to be responsible for the way we use energy Specific Expectations: Describe how the everyday lives of different people and other living things would be affected if electrical energy were no longer available Use appropriate science and technology vocabulary, including explore, investigate, design, energy and survival Design and construct a device that uses energy to perform a task Demonstrate an understanding that energy is what makes the things they do or say happen Identify uses of various sources of energy Understanding Matter and Energy: Grade 2 – Properties of Liquids and Solids Big Ideas: Materials that exist as liquids and solids have specific properties Liquids and solids interact in different ways Some liquids and solids can be harmful to us and the environment Specific Expectations Use technological problem-solving skills, and knowledge acquired from previous investigations, to design, build and test, a structure that involves interactions between liquids and solids Investigate the properties of liquids (e.g. conduct experiments to compare the rate at which different liquids flow) and solids (e.g. conduct experiments to find out ways in which solids can be changed) Understanding Matter and Energy: Grade 4 – Light and Sound Page 1 of 6 ESQ Activity Write-Up 2011 A Stream of Light into the Dark Big Ideas: Light and sound are forms of energy with specific properties Sound is created by vibrations Light is required to see Technological innovations involving light and sound have an impact on the environment Specific Expectations: Investigate the basic properties of light Use technological problem-solving skills to design, build and test a device that makes use of the properties of light or sound Describe properties of light, including the following: light travels in a straight path; light can be absorbed, reflected and refracted Theory & Background Information Engineers are people who solve all kinds of problems. There are many types, including (but not limited to) civil engineers, mechanical engineers and electrical engineers. Electrical engineers are responsible for things such as figuring out how to light up a building or wire the headlights of a car, and create new technology using electricity. Electricity is a form of energy. Energy is what powers our houses, appliances, cars, and even our own bodies. It can come from renewable sources like the sun and wind, or non-renewable sources such as fossil fuels. It is the ability to do work. Some materials allow electricity to pass through, and others do not. A conductor allows energy to pass through, and includes things like water, metal, etc. An insulator does not allow energy to pass, or does so very slowly. This includes materials such as plastic or wood. A light bulb uses electricity to emit light through a simple circuit, which is the path that energy/electricity travels through. A simple circuit is made up of wire (for the electricity to travel through), a bulb (to give off light), a battery (which provides energy), and a switch (that controls when the bulb turns on and off). All of these parts must be connected for the circuit to be complete and for electricity to flow through. Light is examined in the science of physics. Physics is the study of matter and energy. Physicists are also interested in sound, motion, magnetism and heat. There are five properties of light: light travels in waves, light moves very fast, light travels in a straight line, light is a form of energy, and visible light is made up of multiple colours. White light, which comes out of a light bulb, is actually made up of all the colours of the rainbow. This can be remembered by the acronym ROY G BIV (red, orange, yellow, green, blue, indigo, violet). A prism can be used to split white light into all of its separate colours. Page 2 of 6 ESQ Activity Write-Up 2011 A Stream of Light into the Dark When light hits an object, it can act in four different ways. Absorption is when the object takes in the light and does not release any. When all of the light is absorbed, we see black. When all of the light is reflected, we see white. When some light is reflected and some is absorbed, we see colour. The colour which is reflected is the one which we see, and those which are absorbed are not. When light is reflected, it bounces off the object. Refraction is when light goes through an object, but changes speed and appears to bend. Transduction means that the light passes straight through an object. Materials Per Group of 6: Pitcher of water 2-3 skewers Per Camper: Water bottle 1 and a half sheets of constriction paper 2 small light bulbs 2 light bulb holders with wire attached to each side, and connecting the two (two wires should be approx. 8 inches long, and one should be approx. 4 inches) Paperclip Foam cup Per Camp: Several rolls of tape – duct, electrical and masking Aluminum foil Hot glue sticks 4 Hot glue guns Location St. Jerome’s, room 2009 Procedure Preparations 1. Find and clean 25 water bottles. 2. Strip and cut wire. 3. Cut felt into appropriate sized pieces. 4. Attach all wires to light bulb holders. One long wire will be used on each light bulb holder, and the short one will be used to connect them. 5. Go over connections from wires to light bulb holders with aluminum foil and masking tape Introduction 1. Enact how Hansel and Gretel led Mac and Molly to a big, dark cave that they had to cross in order to reach help on the other side. Tell the campers that they will have to build flashlights to help the characters reach their destination. Page 3 of 6 ESQ Activity Write-Up 2011 A Stream of Light into the Dark 2. Ask campers if they know what an engineer is or what they do. Tell them that engineers solve problems in order to help people and that there are many different types. a. Ask if they remember any types of engineers. Examples may include computer engineers, mechanical engineers, civil engineers, environmental engineers etc. b. Let the campers know that today they will be electrical engineers. 3. Explain that electrical engineers design circuits and create solutions using electricity. a. Tell campers that electricity is a form of energy. Ask if they know what energy is, and have them give examples of how it is used. i. Describe energy as the ability to do work. It is what powers our lights, and also our bodies. Energy can come from many different sources, such as food or the sun. 4. Tell campers that some materials allow electricity to pass through, and others do not. A conductor allows energy to pass through, and includes things like water, metal, etc. An insulator does not allow energy to pass, or does so very slowly. This includes materials such as plastic or wood. 5. Explain that today the campers will be building simple circuits to power a flashlight. Using a diagram on the chalk board, display the different parts of a circuit. a. The battery is where the energy comes from to send electricity through the circuit to power the light bulb. b. The bulb is where light is emitted, and is what uses the electricity. c. The switch can open or close to complete the circuit, and control when electricity can flow to power the light. d. Each part of the circuit is connected by wires. i. If there is time, campers can stand in a circle holding hands. They can squeeze hands and try to get the squeeze around the circle to show how electricity travels through a circuit. Have them separate at one part of the circle to show that electricity cannot travel all the way through if the circuit is broken. 6. Tell the campers that in order to understand how light works, they must also learn about physics. Explain that physics is the study of matter and energy. a. Ask campers if they know what matter is. Tell them that matter is everything around us that takes up space. 7. Write and explain the five properties of light on the board. Page 4 of 6 ESQ Activity Write-Up 2011 A Stream of Light into the Dark a. Light moves very fast. b. Light travels in waves. c. Light moves in a straight line. d. Light is a form of energy. e. Light is made up of all the colours of the rainbow. i. Introduce campers to the acronym ROY G BIV (red, orange, yellow, green, blue, indigo, violet) and tell them that those are all the colours that make up visible white light. 8. Tell campers that when light hits an object, several things can happen to it. One of the possibilities is that light can be absorbed, which means that the object takes all the light in and does not release any. Another option is that the light may be reflected. This means that the light bounces back off of the object. a. When all the light is reflected off of an object, we see white. If none of the light is reflected, and all is absorbed, we see black. If some parts of the light are absorbed and others are reflected, we see colour. b. Use different objects around the room to help campers understand these terms. For example, a point to the red shirt of a leader and have campers guess which colours are reflected, and which are absorbed. (Red light is reflected, and all others are absorbed) Activity 1. Begin by handing out one water bottle, a strip of duct tape and a large piece of felt to each camper. 2. Instruct them to wrap the construction paper around the bottle and tape it to the bottle with their duct tape. Make sure there are no gaps in the black construction paper, or light will escape through. 3. Next, hand out skewers, styrofoam cups, the pre-attached light bulb holders, light bulbs and wire. Make sure each camper has two light bulb holders and three stripped wires. 4. Get the campers to screw one light bulb into each of their holders. 5. Next, have them poke two holes in the bottom of their Styrofoam cup. The holes should be at least a couple centimeters apart. 6. The campers can then pull one long wire through each hole going from the inside of the cup to the outside. The bulb holders should be close to resting on the inside bottom of the cup with the bulbs facing up. 7. Next, give each camper a paperclip and instruct them to attach it to one end of the long wire by twisting the wire around the paper clip. The shiny part of the wire must be touching the paper clip. 8. Give each camper a small piece of tape to put over the connection of the wire and paperclip to keep it secure. 9. Hand out more tape (duct tape or masking) to each camper, and get them to attach the cup to the bottom of the water bottle. The open end of the cup should be the part that is taped to the end of the bottle. 10. Give each child another, smaller piece of construction paper and tape. Have them tape the construction paper onto the cup, ensuring that the wire is not taped down and is above the construction paper. Page 5 of 6 ESQ Activity Write-Up 2011 A Stream of Light into the Dark 11. Hand out one battery and a strip of duct tape to each camper. Instruct them to tape the battery onto the side of the water bottle, close enough that the wires are able to reach both ends. 12. Then, assist the camper in taping the shiny end of the long wire (without the paper clip) to the negative end of the battery with masking tape. 13. Leaders can then go around and fill half of each bottle with water, securing the lid after. 14. Tell campers that to turn their light bulb on, they just have to touch the paper clip to the other (positive) end of the battery. 15. The lights should be turned off so that campers can see their light well. Activity Accommodations and Extensions Accommodations If some campers are concerned about the dark, they can test their flashlights at home instead. Campers might need some help taping wires and poking holes through the cup. Extensions If there is extra time, campers can use cellophane to create colourful flashlights. They can also see what kind of shadow shapes they can make on the wall using their light. Safety Considerations Campers should be careful when handling pointy skewers. No materials should be placed in their mouths. If the battery is heating up, campers should be warned to disconnect their circuit. Resources http://www.nasa.gov/audience/forstudents/k-4/dictionary/Circuit.html Page 6 of 6 ESQ Activity Write-Up 2011