The Mirror Puzzle

Somehow, a mirror ‘knows’ to swap left and right, but not up and down.

Ok, stand in front of the mirror and it swaps left and right – you wiggle your right hand, the left hand wiggles in the mirror. But, up and down don’t get swapped, the top of your head is still at the top. More puzzling – when you lie down, the mirror still ‘knows’ when you right hand moves, and ‘shows you’ a left hand moving. Asking a few good questions leads to the real answer. Here’s another Feynman video. Enjoy.