Mirror Puzzle

[RocketManJames]

Some time ago I was asked the following question. After I really couldn't figure it out, I was given an answer, and never did understand it completely. So, I'm seeking an explanation.

When you look in a mirror, left and right is reversed. Yet, up and down are not. Why does a mirror prefer one reflection axis over another?

-RMJ

[unreal_nh]

its hurting my brain to think about it... maybe this will help you:

Link (http://science.howstuffworks.com/question415.htm)

[kidcolin]

it's not reversing anything. it doesn't "flip" left and right. it's just a point to point reflection.

[ QUOTE ]
it's not reversing anything. it doesn't "flip" left and right. it's just a point to point reflection.

[/ QUOTE ]
/images/graemlins/grin.gif /images/graemlins/grin.gif /images/graemlins/laugh.gif /images/graemlins/grin.gif

[mostsmooth]

this is hardly a puzzle

[andyfox]

I don't know the answer, but I think I'll get my car washed.

[Ezcheeze]

Rotate the mirror 90 degrees.

It's the same reason why when you're facing someone you don't agree on which way right (or left) is, but you do agree on up or down. The mirror doesn't flip anything, so when you look at it you see your right side on the right, but someone looking at you from the front would see your right side on the left.

[MMMMMM]

[ QUOTE ]

When you look in a mirror, left and right is reversed. Yet, up and down are not. Why does a mirror prefer one reflection axis over another?

[/ QUOTE ]

If you were lying on your side on the floor instead of standing, then up and down would be appear to be flipped and right and left wouldn't be flipped when you look in the mirror. That is, your "up" ear in reality would be your "other" ear in the mirror--your other ear would appear to be "up".

Therefore, it's not that the mirror has preferences one way or the other; rather it's that you are aligning your body with either the vertical or horizontal axis. (This of course postulates that the room--or gravity--determines up and down; that is, the vertical axis is always the "up-down" axis, and that your own personal frame of reference is subordinate to the greater frame of reference).

If you were to argue againstr this by claiming that even lying down it is your left and right that are switching--by looking straight ahead--you would be changing the very name of the "up/down" or "vertical" axis to the "right/left" or "horizontal" axis. In other words that would be trying to have it both ways).

[baggins]

actually, your right and left don't even change. your left side is still reflected on the left side of the mirror's surface. your right side is reflected on the right. the only thing that's different is that, if you were to look at yourself from the front, you would see a different image than if you were to look at your reflection.

[PairTheBoard]

[ QUOTE ]
Some time ago I was asked the following question. After I really couldn't figure it out, I was given an answer, and never did understand it completely. So, I'm seeking an explanation.

When you look in a mirror, left and right is reversed. Yet, up and down are not. Why does a mirror prefer one reflection axis over another?

-RMJ

[/ QUOTE ]

It's because if you were to turn around and face yourself, thus bringing your right side across from your former left side, you would be Rotating yourself around a vertical axis. You would have to rotate around a horizontal axis to reverse up/down.

PairTheBoard

[udontknowmickey]

The mirror doesn't reflect left to right, but it reflects back to front.

[Moozh]

Left and right is relative to the observer. Up and down is not.

[RocketManJames]

[ QUOTE ]
The mirror doesn't reflect left to right, but it reflects back to front.

[/ QUOTE ]

To me, this explanation makes the most sense. I am sure that many of the other explanations are equivalent, but for now I can live with this one.

Thanks, everyone.

-RMJ