What else are we guessing?

Want to see a magic trick?

Close your left eye and look at the plus sign in the green box. Change the distance of your face from the screen until you're about a foot away and you should notice, without looking directly at it, that the dot in the yellow box has disappeared.

Go ahead. Try it.

This happens because the human eye has a blind spot. In the back of the eye are photoreceptors which are sensitive to light and act like film in a camera. It receives a picture and passes it on to the brain.

The way it passes information through the brain is the optic nerve, a bundle of optic neurons. The optic nerve is like a cable that is in the back of your eye, and for that reason it cannot reflect or receive information. This forms the blind spot that is a couple of inches in diameter in the middle of what you think you're seeing at any give time. No information. Totally blind.

So why isn't there a giant hole of nothingness in the middle of what you're looking at, all the time?

This is because your brain strategically guesses what it thinks you should be seeing based on what's around it. And because, when you look at the picture, there are no dots around what you're looking at, it guesses yellow.

And in this particular example it guesses wrong. So what you think you see isn't really there. Or rather, there is something there that you cannot see.

I love this stuff not only because I'm a geek but because I love having my world turned upside down. I love learning things that I didn't know before.

I love knowing that I don't always know what I think I know. What I think I see isn't always what I'm actually seeing.

Now I suppose this could be a really terrifying thought. But for me this adds an element of mystery to the world, and hopefully a sense of humility.

Knowing that we don't know is a beautiful thing. Not that this would free us from our convictions, but that it might free us from our dogmas-- religious or secular. Not that it would eliminate truth but that it might eliminate arrogance. And not that it would foster doubt but that it might foster openness.

Too many times we think we need certainty when what we need is strength amidst uncertainty. Little revelations like the one above help us take off the training wheels of our own dogmas and certainties and begin to trust the process of discovery. For the dogmatic the risk comes with holding our beliefs a little looser-- not with less passion but with less superiority. For the curious the risk is holding onto something a little tighter. Like a person afraid of falling in love, sometimes we're afraid of falling into faith, even if that person or idea seems to be trustworthy, attractive and (against all odds) interested in us.

So where are you in that tension? Are you in need of loosening your grip on what you know to be true, or are you the one who's gripping nothing, and is in need of a little encouragement to try a little of what terrifies you most: belief.