Constructing%20Ideas%20in%20Physical%20Science

1
Constructing Ideas in Physical Science
CIPS Institute for Middle School Science Teachers

• Joan Abdallah , AAAS
• Darcy Hampton, DCPS
• Davina Pruitt-Mentle, University of Maryland

2
Session 6 Debriefing

• What do you remember from yesterdays session (no
  peeking at text or notes)
• What were the essential questions being
  asked/explored
• What conclusions did we decide

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
Deeper Questions or Possible Misinterpretations

• How come light only bounces off mirrors?

What would you say?
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

6
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/afteri
  mage.html
• Also see
• http//psylux.psych.tu-dresden.de/i1/kaw/diverse
  s20Material/www.illusionworks.com/html/afterimage
  .html
• http//www.wholeo.net/Color/afterImg.htm
• http//www.opticsforteens.org/illusions/afterimag
  e.asp
• http//neuro.caltech.edu/kamitani/fillingInAfter
  image/

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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/question3
  9.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/Blue
  Sky/blue_sky.html
• Note the Tyndall Effect and Rayleigh Scattering
  are the same thing

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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/reflnt
  oc.html
• http//www.physicsclassroom.com/mmedia/optics/opti
  csTOC.html

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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-ref
  ractive.htm Local
• More at
• http//science.howstuffworks.com/lens.htm
  Local
• From Thinkquest - http//www.thinkquest.org/libra
  ry/site_sum.html?tnameC003776urlC003776/ingles/
  print/contact_lenses.htm

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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-ref
ractive.htm Local
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Project 2061 Benchmarks and Target Ideas