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Name: Don
Status: other
Age: 50s
Location: N/A
Country: N/A
Date: 1999 

why does a mirror reflect my image right to left but not top to bottom

If you didn't have feet you wouldn't be asking this question.

The mirror doesn't reflect your image right to left. Whatever is actually on your left still appears to be on your left when you look in the mirror. The right-to-left business is all from the viewpoint of some other person looking at you, and that person sees your left as their right.

Why is this? To put yourself in the position of someone looking at you from behind the mirror, you could imagine a copy of yourself walking through the mirror to the other side. To see you, your copy would then have to turn around, and this presents several options: people with feet tend to rotate about the vertical, so that their feet remain on the ground (and then they forget that a rotation has even taken place, because it's such a common motion). This rotation swaps right and left. If you were a fish, you might equally well decide to rotate about a horizontal line (i.e., do a half somersault), and this would swap top and bottom.

Tim Mooney


The mirror image is a reflection, not a reversal, of the incoming image (light). As the image hits the mirror, so is it seen in its reflection. If we stand in front of the mirror and hold our hand and move it to our left, we see the image also moving left. The same applies to all other directions, including 'up' and 'down'. For a mirror to reverse things, i.e. to project an 'up' movement as a reflection when a down is actually done, or vice versa would be complex, and would have to be accomplished with additional mirror(s) to invert the image in one way or another. As it is, it simply captures light and reflects it back at the viewer without otherwise affecting the image. You can imagine how altering the normal flat mirror also could produce effects you suggest. An example of this would be the funhouse mirrors with concave/convex and combination surfaces. Those mirrors also bend the image in various ways producing humorous results.

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