# Mirrors

Dejection
Posers and Puzzles 19 Feb '09 20:27
1. 19 Feb '09 20:27
People say that mirrors flip left-to-right but not upside down.

I believe that we perceive the flip to be left to right, because when we look at any object in a mirror, for example, ourselves, we mentally rotate the object in the mirror 180 degrees, about a vertical axis, because that is how we rotate in real life. We then compare this rotated image to ourselves, and find that it is flipped left-to-right.

What if we mentally rotated the image about a horizontal axis? when we compare this rotated image to ourselves we find that it is exactly they same, but upsided down.

I think that it is wrong to say that mirrors flip left-to-right but not upside down, i think they are the same thing, it just depends on how you see it. Humans are mentally geared to see it as left-right reflection for some reason or another, that's all.
2. 20 Feb '09 05:501 edit
Originally posted by Dejection
People say that mirrors flip left-to-right but not upside down.

I believe that we perceive the flip to be left to right, because when we look at any object in a mirror, for example, ourselves, we mentally rotate the object in the mirror 180 degrees, about a vertical axis, because that is how we rotate in real life. We then compare this rotated image to ...[text shortened]... are mentally geared to see it as left-right reflection for some reason or another, that's all.
i would argue that the reason mirrors "flip left to right" is because we unconsciously attempt to shift our perspective from the self we are experiencing to the self we are viewing. when we move our right hand, the thing to the furthest right reflected in the mirror is moving. however, we place ourselves mentally in the perspective of the "mirror person" (who doesn't exist)... and we think that when we move our right hand, "he" moves his left.

it is this same perspective shift that leads us to believe text is "flipped around" by reflection, when in fact it is the act of trying to hold a book or a piece of paper for the "mirror man" to read. if you hold a 3-dimensional block of text in between yourself and the mirror, oriented so you can read it, it will look exactly the same reflected in the mirror.
3. 20 Feb '09 20:42
This is the way I think of it;

When we look at a figure, whether it be an image in a mirror or directly an actual physical object, our perception of the directions of up and down on the figure is Independent of the position of the figure relative to your own position because our perception of “up” points towards the SOME imaginary point infinitely far away but our perception of the directions of left and right on a figure is Dependent on the position of the figure relative to your own position because our perception of “left” on a figure can point to one imaginary point infinitely far away in the horizontal direction but our perception of “left” even on the same figure can point to a DIFFERENT imaginary point infinitely far away in horizontal direction if we view the figure from a different angle.
4. PocketKings
Banned from edits
21 Feb '09 03:23
You're all wrong. Those people on the other side of the mirror are highly trained to imitate your every move insantly, and to make you think your ugly.
5. 21 Feb '09 10:13
Originally posted by PocketKings
You're all wrong. Those people on the other side of the mirror are highly trained to imitate your every move insantly, and to make you think your ugly.
You mean I am actually pretty!!! ?
6. 21 Feb '09 10:281 edit
Originally posted by Andrew Hamilton
This is the way I think of it;

When we look at a figure, whether it be an image in a mirror or directly an actual physical object, our perception of the directions of up and down on the figure is Independent of the position of the figure relative to your own position because our perception of “up” points towards the SOME imaginary point infinitely ...[text shortened]... point infinitely far away in horizontal direction if we view the figure from a different angle.
I am not sure but I think actually my reasoning here may be subtly flawed ðŸ˜• :

I have failed to take into account the fact that mirrors are normally orientated vertically and the surfaces we tend to notice when seeing their reflection in the mirrors tend to also be vertical.
If you hold a book in front of you so the pages are horizontal and orientate it so that you can read the words and then place a mirror vertically slightly farther away from you but also in front of you so that you can see the reflection of the words, you will see the words in the mirror upside down and not back to front. The same applies if you swap the positions and orientations of the mirror and the book around so that the mirror is horizontal and the book is vertical.
Thus this doesn’t quite depend entirely on our perception as I suggested?
7. sonhouse
Fast and Curious
21 Feb '09 21:061 edit
Originally posted by Andrew Hamilton
I am not sure but I think actually my reasoning here may be subtly flawed ðŸ˜• :

I have failed to take into account the fact that mirrors are normally orientated vertically and the surfaces we tend to notice when seeing their reflection in the mirrors tend to also be vertical.
If you hold a book in front of you so the pages are horizontal and orie ...[text shortened]... the book is vertical.
Thus this doesn’t quite depend entirely on our perception as I suggested?
If you put two mirrors at right angles to each other, like in the corner of a room, meeting with a very accurate line, no gaps, and you look at that one, the perspective is exactly the same as if you were in that spot, that is to say, you move your right hand and the opposite hand moves, showing the perspective is exactly the same as your own, the opposite of a regular mirror, which, when you look at the image, you move your left arm and the image looks like it's moving it's left arm. It is not a matter of inner perspective, if you have both mirrors side by side, you can see the difference. Like if a wall has mirrors in it and they meet at the corner like I said, just moving over to the middle of the wall gives you the view of a normal mirror but when you look at the corner reflector, the opposite perspective shows. Try it if you don't believe me. Do the experiment, mirrors are cheap.
For it to work, however, the corner mirrors must be exactly at 90 degrees apart, otherwise overlapping images ruin the effect.
8. 14 Mar '09 20:50
It is simply because our eyes are fixed horizontally.
9. 19 Mar '09 11:18