Mirror Reflection: Why Does Object Look Smaller?

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Discussion Overview

The discussion revolves around the perception of object size in mirror reflections, particularly why objects appear smaller when they are farther from the mirror compared to those that are closer. It includes conceptual explorations of light behavior, image formation, and human perception.

Discussion Character

  • Conceptual clarification, Debate/contested

Main Points Raised

  • One participant questions why an object placed further from a mirror appears smaller, suggesting confusion about the light reflecting from the same object (the mirror).
  • Another participant explains that an object appears to be behind the mirror at the same distance as it is in front, leading to the conclusion that farther objects appear smaller in the mirror.
  • A different viewpoint states that a flat mirror does not change the size of objects, asserting that they appear the same size as when viewed directly, provided the distance to the eye is the same.
  • Another contribution discusses how the perceived size of an object is determined by the angle it subtends at the retina, noting that farther objects produce a smaller angle and thus appear smaller, while also mentioning the role of 3D vision in size perception.
  • This participant also highlights that the brain's adaptation to perceive closer objects as larger plays a significant role in size judgment, which can lead to optical illusions.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between distance and perceived size in mirrors, with some asserting that mirrors do not alter size perception while others argue that distance does affect perceived size. The discussion remains unresolved regarding the exact mechanisms of perception in this context.

Contextual Notes

Some assumptions about light behavior, perception, and the role of the brain in interpreting size are not fully explored, leaving room for further discussion on these topics.

Alex Jong
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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
 
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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.
 
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?

mirrorsfigure2.jpg


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