Mirror Puzzle

RocketManJames · #1 09-11-2005, 06:26 AM

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 · #2 09-11-2005, 08:45 AM

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

Link

kidcolin · #3 09-11-2005, 08:57 AM

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

#4 09-11-2005, 09:08 AM

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

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

mostsmooth · #5 09-11-2005, 10:43 AM

this is hardly a puzzle

andyfox · #6 09-11-2005, 11:48 AM

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

Ezcheeze · #7 09-11-2005, 04:21 PM

Rotate the mirror 90 degrees.

#8 09-11-2005, 07:32 PM

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 · #9 09-11-2005, 10:55 PM

[ 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 · #10 09-12-2005, 12:00 AM

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.