> And if you're lying on your side, one eye open, left and right are still reversed nothing to do with binocular vision or with orientation then - the 'simple' answer is that a mirror image is simply that: clockwise becomes anti-clockwise, left becomes right, helices spiral the other way a mirror in a forest with nobody looking produces the same effect. You could draw little diagrams with light rays etc. to illustrate but it's a tad difficult in text try visualising the reflection as a 'virtual' object existing behind the mirror and all should (or might) become clear.


I have no idea what any of that means. :-)

I think Darien's reference of Martin Gardner's work makes the most sense to me. Because a mirror *doesn't* reverse left and right. If you raise your left hand, isn't the hand that is raised in the mirror on the left side as you face it? Mirrors actually reverse only in the direction perpendicular to its plane -- what is in the front is moved to the back and vice versa. This appears to reverse left and right also, because left and right are indicators relative to the angle you look at something. If you look at something from the front vs. something from the back, left and right will be switched.

On the other hand, "top" and "bottom" are not indicators that depend on where you are horizontally. The top is always the top, and the bottom is always the bottom -- so these are not reversed when you look at an image that's reversed front to back.

Put the mirror face up on the floor, and it's a different story -- in that case, the perpendicular dimension is vertical, and top and bottom are therefore reversed.

Having said all that, I have no idea if this will make more sense to anyone but me than enile's explanation does.