Another Puzzle: Reversed Text? - Question of the Week 2/10-2/14

Consider this problem regarding images in a mirror: Suppose that you hold the transparency in the photograph below in front of a mirror.

How will its reflection appear? Is the image:

• (a) inverted top-to-bottom?
• (b) inverted left-to-right?
• (c) inverted front-to-back?
• (d) not inverted at all?

Write out the word LIGHT as it will appear in the mirror.

After February 14th, 2014, click Read More for the answer

The answer is (c); the image in a plane mirror is inverted front-to-back, and in no other direction. Because the transparency under consideration here has no depth, this bit of information is irrelevant, as can be seen in the photograph below.

Notice that the word is not inverted either in the top-to-bottom or the left-to-right directions. One reason for possible confusion here is that most people are used to holding up text with an opaque background in front of a mirror, in which case the image reads backwards. However, if you examine the situation carefully you will notice that in order to see the writing in the mirror the page had to be reversed, so even in this case there is no left-to-right inversion created by the mirror.

Notice, in the photograph above, that the hand is indeed reversed front-to-back!!