Why does a mirror switch left and right and not up and down?

Question

If you see your reflection in mirror, then your right hand is the left hand of the your reflection and vice versa. Why same does not happen with up and down?

And why this symmetry axis in the case of mirror is vertical?

Answer 1

Actually, the mirror switches front and back, not left and right. The image of your right hand is still on the right side of the mirror image, but the image is facing the other direction.

If you want to make a mirror switch up and down, stand on it. If you want to make it switch left and right, stand beside it. In every case, the mirror switches through the plane of the mirror.

Answer 2

It doesnt. Instead it changes foward/backward directions. Changing of left and right is just a popular myth.
Mirrors don't switch left/right orup/down, but we do especially when we rotate objects about an axis so as to orient them facing a mirror. Take a piece of paper and write a word on it. To get a mirror reflection of that word, you can flip it about the x-axis or the y-axis. The default choice is almost universally y-axis, which is why the text appears "mirror-reversed" or right-to-left. But you could as well flip the piece of paper about the x-axis, in which case the text will appear upside down, but left-to-right.

Answer 3

Place a H, T, L and R on your Head, Toe, Left and Right hands respectively. Notice in a mirror that H and T are reflected the same as R and L. The difference is that left and right 'look' the same while head and toe can't be confused.

Answer 4

It doesn't switch anything, you do. It reflects the light back exactly as it goes in. Relative to the original spatial orientation, everything is still pointing exactly where it was pointing to start with. Things that point up, still point up. Things that point east, still point east. Within a given coordinate plane, up, down, east and west are absolute directions.
Right and left, however, are always relative to the observer. When you face a friend, you both agree on what’s up and down, but right and left are relative to each of you. So it is when you look in a mirror.

Answer 5

I think that it because when you move your LEFT hand, the mirror you, also moves YOUR left hand. The retina is receiving crossed, reflected light.

So,next time you have time to spare on this and you are looking at yourself in the mirror, be very concerned if the you in the mirror moves HIS left hand in response to your LEFT hand.

This means either;

A: the mull is better than you thought
B: the mushrooms you found under the fridge are not going to be suitable for the salad you were going to make for your parents when they come over Sunday
C: it is stargate NOT a mirror and there is a stranger in your bathroom wall
D: all of the above...

Answer 6

There are axes of symmetry about which the images are rotated and in this case, the image is rotated about a vertical axis between you and the reflection in the mirror. In the case of image formation with a lens, if the image is inverted, it is also rotated right to left etc. and we have a rotation about an axis which is a horizontal line through the object, lens and the image.

Answer 7

As another answer has indicated, this has been asked before. Many of the other answers are cogent and correct.

The best reply I have seen to this was in Martin Gardner's book (see source below), but it was written by John Langdon Taylor, Jr., who had read the original magazine column and written a reply that Gardner reprinted in a subsequent issue. Taylor writes:

"Humans are superficially and grossly bilaterally symmetrical, but subjectively and behaviorally they are relatively asymmetrical. ... When we stand before a mirror, we see reflected a superficially bilaterally symmetrical structure, and we are misled by this apparent symmetry into treating the system as if ourselves and our reflection were identities rather than enantiomorphs (entities of opposite 'handedness'). ... We are ... led to the erroneous statement that when we move our right hand, our mirror image moves its left hand."

Taylor's letter is much longer and much clearer than this fragment of his splendid prose would suggest.

When R. S. Wiener read Taylor's reply, he sent his own response, also reprinted by Gardner, which is very funny and worth the price of the book. I will give you just a bit of it:

"Standing on my head on the floor in front of the mirror, I realized that I could not see all of my image. All I could see were two feet. The one that I recognized to be that which I usually term the left one was..."

Enjoy!

Answer 8

If you mark your right hand you will find it is still on the right.
To change it you would have to have your reflection turn around with it's back to you and you stay facing the same way,then you would find the right was on the left.
Head to toe is easier to imagine than left to right.

Answer 9

this question has been asked before and a mirror doesnt switch anything. it is merely a DIRECT REFLECTION of what is in front of it. if you were to hold your head sideways in front of a mirror and pull on your left ear it would appear to be your right ear in the mirror, just as it does when you are upright. the mirror doesnt 'switch" one direction and not the other.

Answer 10

While standing in front of the mirror, ask your friend to stand to the left of you.

If left and right were interchanged in the mirror, the friend’s image must be in front of you and your image must be in front of your friend.

But nothing of this sort occurs; your image is in front of you and his image is in front of him just as ups and down.