egamI rorriM | Mirror Image

❦ It is funny how little details of our daily lives influences how we see and think about things. Our notion of up and down is a very powerful influence. My brother used to ask all kinds of hard to answer questions, such as "Why do clouds stay clumped together and not spread out like smoke in a room." Our idea of horizontal and vertical seems equivalent. You can just rotate something 90 degrees and switch between them. But there is a subtle difference. One time my brother pointed out to me that horizontal planes can not intersect while vertical ones can; I had never thought about it before. Horizontal has a stricter definition than vertical. We could make up new vertical definitions like vertical-away and vertical-across to discriminate between types of vertical planes. Say we are facing north, then vertical-away planes that are along north-south lines can not intersect. Similarly, vertical across planes that are on east-west lines can not intersect either, like horizontal planes.

❦ Here is another simple question. Why are words reflected in a mirror flipped right and left, but not up and down? Think about it for a moment; it seems strange.

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❦ I was thinking about this mirror image problem on my commute this morning and got the idea for this post. I think this is also related to our notion of up and down versus right and left. The mirror isn't really flipping anything. What is closer to the right is closer to the right in the image, what is higher is higher in the image, etc. It seems flipped because we imagine it as looking through a piece of glass at the image on our shirt, but to do this we would walk around to the other side of the glass and face ourselves (not face away in the same orientation). We imagine up and down remaining the same and that we would rotate left or right, on a vertical axis, which exchanges left and right in the word orientation. However, if we were talented enough, we could also get to the other side of the glass by flipping over it and landing on our hands upside-down to face back towards ourselves. If we were used to getting around and looking at things this way then the mirror image would instead appear upside-down reversed to us.

❦ This is a bit of a tangent but I used to work in a printing press darkroom.  Among other things I would develop film images of magazine articles.  There was not much else to do so I would read the articles while waiting; however, the film was often reversed in the solution baths.  I got so used to reading reversed text that after a while I had to stop and think for a moment if text was in the right orientation or not.