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CIPS Institute for Middle School Science Teachers. Constructing Ideas in Physical Science. Joan Abdallah , AAAS Darcy Hampton, DCPS Davina Pruitt-Mentle , University of Maryland. Session 6 Debriefing. What do you remember from yesterday’s session (no peeking at text or notes)
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CIPS Institute for Middle School Science Teachers Constructing Ideas in Physical Science Joan Abdallah, AAAS Darcy Hampton, DCPS Davina Pruitt-Mentle, University of Maryland
Session 6 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 8/2-8/13
Deeper Questions • What deeper questions could you envision students asking? • What misconceptions or misinterpretations can you foresee? • How or what would you say? 8/2-8/13
Deeper Questions or Possible Misinterpretations “How come light only bounces off mirrors?” What would you say? 8/2-8/13
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 8/2-8/13
Why Do We “See” After We Close Our Eyes? • You see because light enters your eyes and produces chemical changes in the retina, the light-sensitive lining at the back of your eyes. Prolonged stimulation by a bright image (here, the light source) desensitizes part of the retina. You continue to see the image for a short time after the stimulus goes away. This is called an “afterimage” • Source: http://www.exploratorium.edu/snacks/afterimage.html • Also see: • http://psylux.psych.tu-dresden.de/i1/kaw/diverses%20Material/www.illusionworks.com/html/afterimage.html • http://www.wholeo.net/Color/afterImg.htm • http://www.opticsforteens.org/illusions/afterimage.asp • http://neuro.caltech.edu/~kamitani/fillingInAfterimage/ 8/2-8/13
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] • 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 8/2-8/13
Convex vs. Concave Mirrors • A Concave mirror bends away from the viewer • Like the inside of a spoon • Tends to make things look bigger (closer) • Smaller field of view • A Convex mirror bends toward the viewer • Right side view mirror • Tends to make things look smaller (further away) • Larger field of view • Sources and for more detail • http://www.amherst.edu/~physicsqanda/Mirror2A.htm • Excellent – must see – All mirror info [Local Copy] • http://www.physicsclassroom.com/Class/refln/reflntoc.html • http://www.physicsclassroom.com/mmedia/optics/opticsTOC.html 8/2-8/13
Eye Sight • Nearsightedness (myopia) • In nearsightedness (myopia), the light from distant objects gets focused in front of the retina rather than on it. • Myopia can be corrected by using a concave lens to diverge, or spread out, the light so that when it passes through the lens system, it comes to focus on the retina. • Source: http://health.howstuffworks.com/vision-refractive.htm [Local] • More at: • http://science.howstuffworks.com/lens.htm [Local] • From Thinkquest - http://www.thinkquest.org/library/site_sum.html?tname=C003776&url=C003776/ingles/print/contact_lenses.htm 8/2-8/13
Eye Sight • Farsightedness (hyperopia) • In farsightedness (hyperopia), the light gets focused in back of the retina rather than on it. • Hyperopia can by corrected by using a convex lens to concentrate or converge the light so that when it passes through the lens system, it comes to focus on the retina. Source: http://health.howstuffworks.com/vision-refractive.htm [Local] 8/2-8/13