1. Constructing Ideas in Physical Science Joan Abdallah, AAAS Darcy Hampton, DCPS Davina Pruitt-Mentle, University of Maryland CIPS Institute for Middle School Science Teachers

2. AAAS/DCPS CIPS Workshop8/2-8/13 2 Session 7 Debriefing What do you remember from yesterday’s session (no peeking at text or notes) What were the “essential questions” being asked/explored What conclusions did “we” decide

3. AAAS/DCPS CIPS Workshop8/2-8/13 3 Deeper Questions What deeper questions could you envision students asking? What misconceptions or misinterpretations can you foresee? How or what would you say?

4. AAAS/DCPS CIPS Workshop8/2-8/13 4 Deeper Questions or Possible Misinterpretations “How can we see black when black doesn’t reflect?” “Why is the sky blue? Red ?” “What’s up with a black light?” What would you say?

5. AAAS/DCPS CIPS Workshop8/2-8/13 5 Target Ideas A light interaction occurs when a source of light illuminates a nearby object During a light interaction, light energy is transferred from the source to the receiver Light travels in straight-lines To see an object, light from that object must enter the eye. Visual energy is a form of energy associated with seeing things A shiny object reflects light in a particular direction A clear object reflects light in a particular direction and transmits light A white, non-shiny object reflects light in all directions away from its surface A black object absorbs the light striking it Temperature energy is a form of energy

6. AAAS/DCPS CIPS Workshop8/2-8/13 6 Black “Absorbs” Students discovered that light energy is absorbed by black objects and is transformed into another form of energy, "temperature energy." For this reason, black objects get warmer than white ones

7. AAAS/DCPS CIPS Workshop8/2-8/13 7 Why is the Sky Blue The physical phenomenon called Rayleigh scattering causes light to scatter when it passes through particles that have a diameter one-tenth that of the wavelength (color) of the light. Sunlight is made up of all different colors of light, but because of the elements in the atmosphere (mainly nitrogen and oxygen) the color blue is scattered much more efficiently than the other colors. So when you look at the sky on a clear day, you can see the sun as a bright disk. The blueness you see everywhere else is all of the atoms in the atmosphere scattering blue light toward you. (Because red light, yellow light, green light and the other colors aren't scattered nearly as well, you see the sky as blue.) Source: http://science.howstuffworks.com/question39.htm [Local]http://science.howstuffworks.com/question39.htmLocal See also: http://www.why-is-the-sky-blue.org/ http://www.sciencemadesimple.com/sky_blue.html http://math.ucr.edu/home/baez/physics/General/BlueSky/blue_sky.html Note: the Tyndall Effect and Rayleigh Scattering are the same thing

8. AAAS/DCPS CIPS Workshop8/2-8/13 8 Project 2061 Benchmarks and Target Ideas A light interaction occurs when a source of light illuminates nearby object. The source can either be an object that emits its own light, or an object that reflects or transmits light. Electrical energy can be produced from a variety of energy sources and can be transformed into almost any other form of energy… In an electrical circuit, energy is transferred from an energy source (e.g. chemical battery, generator or solar battery) to an energy receiver (e.g. bulb, buzzer, or motor).

9. AAAS/DCPS CIPS Workshop8/2-8/13 9 How can we see black when black doesn’t reflect? Although Black absorbs most light, it doesn’t absorb everything – therefore we do have some reflections that we can see Even if it absorbed “everything”, our eye would be able to see the absence of light, and would make, at least, the outline of the object and middle –Think about the negative from black and white film. The light areas become black and white areas become black, but your eye can still make a picture Also – low light is viewed by the rods in the retina. Your eye is very sensitive to slight changes in low light so can see nuances in dark pictures/objects. It is much more difficult to see slight differences in very bright objects. For more about vision see: http://science.howstuffworks.com/eye.htm/printable [Local] http://science.howstuffworks.com/eye.htm/printableLocal

10. AAAS/DCPS CIPS Workshop8/2-8/13 10 How does a black light work? A black light mainly emits ultra-violet, not visible light (Just UV-A, not the harmful UV-B and UV-C) The ultra-violet light causes certain substance, phosphors, to glow –Some paints –Fabrics –Plastics –Fluorescent objects –Laundry detergent has phosphors to make whites glow better in sunlight See: http://science.howstuffworks.com/black-light.htm/printable [Local]http://science.howstuffworks.com/black-light.htm/printableLocal

11. AAAS/DCPS CIPS Workshop8/2-8/13 11 Other ideas—these were ideas that they wanted to know more about— about how they work Polarized light Iridescence color (bubbles) Lasers Fiber optics Single lens reflex camera Compact disc CD Holgram (interference pattern)