4 ms·

Put a mirror on the ceiling and it will "flip" things vertically and not horizontally.

• quietbritishjim 6y ago
  There are really two "flips" that are often talked about with a mirror: 1. It flips things in the direction perpendicular to the mirror. If you're facing a normal wall-mounted mirror then that means it flips your "forward" into your "backwards". This is a real physical effect that no one would normally dispute. 2. It appears to flip things left to right, and most people (before mirror-flipping enlightment) would reasonably believe this. But it's a human psychological effect, not a real physical one. This article is about the second point. You're talking about the first point. The placement of the mirror is a red herring: even with a ceiling mounted mirror, if you show a piece of paper to it by putting it above your head in the natural unenlightened way and look up, you'll find the text is still flipped left to right. In fact it maybe even emphasises the illusion because you can turn to face any direction (and without thinking you'll turn the piece of paper too of course) and still see the same effect! (BTW I upvoted your comment because it's not the only comment to post this mix up - but it seems to be the first - so I think it deserves a bit of visibility for others thinking the same thing.)