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Medical Optical Illusion

  1. Feb 20, 2006 #1
    We are all familiar with the illusion of the wheels on a car on television appearing to spin backwards when the car is travelling forward, this being caused by a mismatch of the picture frequency and the wheel's rotational speed.

    However I have also observed this phenomenon in the real world when looking at the wheel of the car beside me as I drive down the road. This is in normal daylight, so it is not a strobing effect from artificial light.

    Can this be explained perhaps in terms of an operation frequency of the brain / sight ?
  2. jcsd
  3. Feb 20, 2006 #2
    I'm not sure if this is the reason, but it might add to it...
    The eye does not usually look directly at an object, but "quivers" from side to side. This frequency might partially explain the effect.

  4. Feb 24, 2006 #3
    Ever notice how that optical illusion does NOT occur at slow rotation speeds?
  5. Feb 25, 2006 #4
    While your driving? Keep your eyes on the road and your hands upon the wheel. :rofl: :zzz: :surprised o:)
    Last edited: Feb 25, 2006
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