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Question about mirrors

  1. Jun 26, 2014 #1
    If light bounces from a mirror into your eyes it's from 1 object (the mirror) if i were to have 2 objects placed somewhere then why would the one placed further look smaller in the mirror? The light is bouncing of the same object right?(the mirror) thanks for the help and sorry for the bad english thanks
  2. jcsd
  3. Jun 26, 2014 #2


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    Science Advisor

    An object in a mirror appears to be behind the mirror- the same distance behind as it is in front of the mirror.
    Thus, if object A is farther from the mirror than object B, its image will appear to be farther behind the mirror than the image of object B, so smaller.
  4. Jun 27, 2014 #3


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    Staff: Mentor

    A flat mirror reverses the direction of the light, but the divergence and angles of the rays stay the same. The end result is that objects appear the same size in a flat mirror as they do if you were looking directly at the object. (As long as the distance the light travels between the object and your eye is the same in both cases)

    Do these pictures help?


    http://cnx.org/content/m42456/latest/Figure 26_02_06.jpg (This picture is large, so I didn't insert it into the thread.)
  5. Jun 27, 2014 #4


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    Gold Member

    You would also like to know why far objects look smaller than near objects.

    What determines the size of an object is the size of that object on the retina. A far object will produce an angle lesser than an object which is near, resulting in a smaller image produced on the retina, and thus looking smaller.

    The angle itself does not determine the actual size. A pencil may look larger than a sky scraper when it is held very close to the eye.But we know that the pencil is smaller. Why? Our 3d vision plays a great part in determining the distance. This combination of abilities is used to judge the size of the pencil.

    Our brain is adapted to think that an object closer should look larger. This is sometimes used for producing optical illusions.
    Last edited: Jun 27, 2014
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