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Phase Reversal? in Mirrors
Name: Kamille M.
Status: student
Age: 17
Location: N/A
Country: N/A
Date: 2000-2001
Question:
How come when you face a mirror and raise your right
hand, it seemed that your left hand was reflected? Is this what they call
phase reversal?
Replies:
Kamille,
It's referred to as image reversal. The mirror simply reflects back to you a
point-to-point reproduction of what it "sees." If you imagine yourself to
be on
the other side of the mirror standing behind the image, it only appears that
your image raised the hand opposite to the one you actually raised. This
happens because you and your image are not the same thing. Because of this
reversal, when you look in a mirror, you don't see what the world sees
when it
looks directly at you. You're quite accustomed to seeing your mirror image.
Except in a photograph, you probably have never seen a reflection of yourself
that was not left-to-right reversed.
If you would like to see a mirror image of yourself that is not reversed
left-to-right, here's how to do it:
Place two mirrors at a 90 degree angle to each other so that their vertical
edges are touching. Stand directly in front of the pair and look at the
intersection point, Now, try to comb your hair while looking at the image of
your face. Interesting isn't it? The paired mirrors produce a double
reflection. the second reflection reverses the first reversal and you're
seeing
yourself as others see you.
Here are two even more interesting questions you might want to investigate:
1. Since the mirror appears to reverse things left-to-right, why doesn't it
reverse things top-to-bottom?
2. What is the shortest "full-length" mirror that will let you see yourself
full-length?
Have fun.
Regards,
ProfHoff
It is not phase reversal. It is front-back inversion due to the reflection
process. It is similar to taking every piece of the "front" of your body
and switching it with the corresponding "back" piece. What is closest to
the floor remains closest to the floor. What is closest to the wall on your
left remains closest to that wall. However, the front and back of your body
reflection are facing opposite those of your real body.
Kenneth Mellendorf
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Update: June 2012
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