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Light Concepts

Initial perceptual naive misconceptions (any age)

Misconceptions (Explanations, Naive understanding, Misconceptions, or Perceptual responses)

See also - Eyesight and Light: Examples of how difficult it is to change student's Misconceptions

Light transmission

  1. Reflected light is shine or glare not something associated with seeing objects.
  2. Light can only do some of the following: be absorbed, blocked, reflected, or refracted by an object.
  3. Light is not reflected in a predictable manner and angle.
  4. Light is not refracted in a predictable manner and angle.
  5. The reflection of an object is located on the surface of the mirror. The reflection is often thought of as a picture on a flat or curved surface.
  6. To be seen in a mirror, the object must be directly in front of the mirror or within the line-of-sight from the observer to the mirror.
  7. Light always passes straight through transparent material (without changing direction).
  8. When an object is viewed through a transparent material, the object is seen exactly where it is located.
  9. Light only reflects from mirrors and shiny objects.
  10. If students are asked what helps you see? Most will answer glasses, seeing-eye dogs, binoculars, hand lenses, or microscopes, not light.
  11. Bright light travels further than dim.
  12. Light travels further at night.
  13. Light only travels a short way.
  14. Light stops.


  1. White light is pure and colorless light.
  2. Color is a property of something other than a property of light.
  3. Sunlight is red, yellow, or orange
  4. Light travels from our eyes so we can see.
  5. Light eminates from the object being looked at (not a property of what light is reflected or absorbed).
  6. A prism or colored filter (piece of gel or plastic) puts color into light when it passes through it.


  1. Bats and owls can see in complete darkness.
  2. Humans can see in complete darkness after the eye adjusts. Students can persist with this belief by simply extending the time minutes, hours, days, years...


  1. Shadows come from me. From other people or objects.
  2. Shadows follow you.
  3. Shadows come from clouds or the sky
  4. Shadows come from the sun as it shines on us and reflects off us to make a shadow.


  1. Sunlight reflects from rain
  2. Water sprinkler makes rainbows
  3. Bubbles make rainbows
  4. Mist, moisture in air causes rainbows
  5. Pot of gold
  6. Water falls through light. The water has color in it and when it hits the light you see it.
  7. When light hits falling rain it makes all the colors in the raindrops to reflect off one another and the colors that are the same come together.

Beginning (preschool - 7 years)


  1. Light needs energy.

Intermediate (7 years - 11 years)


  1. Light travels in a straight line until it strikes an object.
  2. Light can be reflected by a mirror, refracted by a lens, or absorbed by the object.
  3. Light interacts with matter by transmission (including refraction), absorption, or scattering (including reflection).
  4. To see an object, light is emitted by the object or reflected from its surface and enters the eye.
  5. Objects are seen only if they are illuminated by light interacting with them.

Literate (11+)


  1. Light interference is when two waves mix. When waves meet or interfere the result will range from two crests or troughs combining to form a higher crest or lower trough, hence more intense or brighter light, to a crest and a trough combining to cancel each other, hence a less bright or intense light ranging from less light to dark. This can be observed in a double slit experiment when light, with the same wavelength, passes through the slits, the waves interfer with each other which can be projected onto a screen where the interference pattern can be seen as bands of light and dark.
  2. Diffraction is the spreading out of waves after light passes through a narrow gap.
  3. Refraction is the bending of light when it travels through different transparent mediums.
  4. Light is reflected at an angle proportional to the angle it strikes an object.
  5. Light is refracted at an angle related to the angle that it enters or leaves a medium and the density of the mediums. Color is a property of light.
  6. White light has all colors. Black is the absence of light and/or color. Computer code #000 or #000000 has a value of zero, hence black. Code #fff or #ffffff has the highest value, hence white. Check out base 16 for explanation of f having a number value.
  7. White light can be refracted to view a spectrum. Light is a form of energy that can be transfered or changed to other forms of energy.
  8. An electromagnetic wave model and a photon model explain features of electromagnetic radiation each describe some common applications of electromagnetic radiation.


Dr. Robert Sweetland's notes