left, right, mirror

Why does a mirror changes left with right but doesn't change up with down?

A mirror doesn't change left and write. It changes back and front.

Normally you map youself onto your reflection by rotating on the upright axis. (i.e turning round). Instead, if you map yourself onto your reflection by rotating about the horizontal axis (in the plane of the mirror), by doing a handstand rather than turning around, you'll see that the mirror has in fact changed your up and your down around, not your left/right.

Magic!

Tilt you head 90 degrees clockwise, and it'll change up with down.

Bob H

Mirrors exchange left and right? Since when?

It doesn't reverse left and right (if you use an ordinary planer mirror). Try this: Write a message on a sheet of transparent plastic (e.g., viewgraph film), stand in front of a mirror and hold the message up in front of you so that you can read it off of the plastic. If you look at the message in the mirror, you will see that it can be read normally. Turn the plastic around by exchanging its left and right edges so that the message faces the mirror. The message in the mirror will appear left-right reversed, but so will the message on the plastic (as you look through it). Now start again, but turn the plastic around by exchanging it top and bottom edges. The message in the mirror will appear top-bottom reversed.

I know of two different ways that a person can quickly learn to write their name (or similar text) in 'mirror writing'. One method is to move your left and right hands symmetrically about the vertical plane that passes between the left and right halves of your body. Trace the message with your left (non-writing) hand and, write the reversed message using your right hand by mirroring the left hand's movements. Try not to concentrate on what your right hand is writing, just on making the mirror movements.

My second way is even easier, and can be learned by most people almost immediately, but isn't as flexible. Can anyone guess the second technique? Hint: I doesn't require any special equipment beyond the pen and paper, except that a book makes it easier.

Carl G.

It doesn't exchange left and rignt. Points along any line parallel to the mirror surface rmain in unchanged order in the reflection.

It does exchange near and far in the sense of reversing the order of points along lines perpendicular to the mirror surface.

'Carl G.' schrieb:

That's a good idea! Makes it clear that left is still left (d'oh!).

[Mirror writing]

Solution:

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Hold a book with a piece of paper on the underside in front of you; write on teh underside.

Have fun below

On 26 Aug 2002, Dan Cernat wrote:

A mirror doesn't change left and right, a mirror changes front and back.

Imagine the following: you've placed a red glove on your right hand, and a black one on your left, and you now face a mirror that is north of you. What is the result? Your black glove (the left one) is to the west, and the image's black glove is to the west. The red glove is to the east in both instances. However you are facing north and the image is facing

Or do it on your forehead.