Sep 11th, 2008

The mirror’s enigma

Ever since I was a kid I’ve been very observant, always trying to understand why things are like they are or why I perceive them the way I do. Even though I can’t say I have studied physics, philosophy, neurology or psychology very deeply during my life, they are subjects that have always fascinated me. Often, upon being perplexed by some mystery of nature, I would keenly observe and finally conclude its reasons and solve it, as if it were a puzzle. There was one such mystery that I was never able to solve, though. I believed that I was simply not smart enough, so for the longest time I forgot about it. But today, as I was waking up, I seem to have found the answer.

This mystery is a trivial one, like most others that have puzzled me over the years. The enigma is: why do we see ourselves horizontally flipped in the mirror, and never vertically? It doesn’t matter where I’m looking from, the freckle on the left side of my face will always be on the right, but my head will never be where my feet are. I had always deduced that it was a matter of perception, but I was never able to solve the riddle in its entirety.

Now I believe I have found the reason. You may already have been ‘enlightened’, but if you have not, please read on. The key is: gravity. We are beings that not only cannot imagine living without gravity, but even our bodies have been shaped to match this fact, as we are symmetrical on an axis perpendicular to the ground. What this reveals is that we find left and right to be interchangeable, but never up and down; we cannot conceive the possibility of the sky being under our feet, but we very often take a right turn when we should have taken a left.

The next key, then, are expectations. If you ask someone to turn a chair around, will you expect them to put it upside down, with its legs up in the air? Of course not: they will turn it around a vertical axis, because gravity has conditioned us to it, so it’s the most logical response. They won’t even think of doing anything other than the latter, unless they’re being playful.

You might already see where I’m going with all this. Take a look at the following picture:

The leftmost picture is what you’ve always seen when you look in the mirror; nothing new. The second is what you’d expect to see, with the image in the mirror ‘corrected’. And on the third hinges my argument. If you look carefully, the second and third reflections are the same image, rotated 180º of one another; the third was simply the result of ‘flipping’ the image (as you would a paper sheet) vertically instead of horizontally. In fact, I could flip the image around any odd axis, and the result would be the same, only crooked to a different angle. What does this boil down to, then?

We choose to see the image in our mirror as having been ‘flipped’ horizontally, when in reality it could have been any direction, simply because we are conditioned to our expectations: that the feet must be against the ground. The correct image, in our mind, is the horizontal ‘unflip’, because flipping vertically would result in an image that is opposed to gravity; thus, we eliminate any other possible unflip. So, next time you’re in front of the mirror, looking at your face, stop and think that what you see is an inverted image, and left and right, up and down, or even north and south make no difference: it’s just backwards.