Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Mirror image reversal - why only l/r, not up/down

  1. Aug 31, 2005 #1
    what explains the fact that mirrors only reverse an image left to right, not up and down?
  2. jcsd
  3. Aug 31, 2005 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Mirrors don't reverse either of those.
  4. Aug 31, 2005 #3


    User Avatar
    Homework Helper

    They reverse in/out. The reason it seems the left/right directions are reversed is because when we decide which hand our image is raising, we unconsciously put ourselves in its place, which involves rotating our orientation around our vertical axis so we face the same direction, undoing the in/out flip at the cost of a left/right flip (in our minds eye). We might just as easily flip about our horizontal axis and decide up/down is flipped, but since we are more or less symmetrical left to right (and also since we rarely physically perform that rotation), that is a much less natural choice.
    Last edited: Aug 31, 2005
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook