Flashing Lights

Are these two boys (who happen to be my sons) happy? Looks can be deceiving...

The other day we drove one hundred miles to San Francisco. We visited the Exploratorium, a family-friendly museum with lots of hands-on stuff. At one end of the large one-room building (I believe it was originally built as an exhibition hall), there were a series of colored lights flashing randomly on the wall. A nice decoration, I thought.
We spent several hours pressing buttons, moving levers, making giant bubbles, and experimenting with sound. After awhile, out of the corner of my eye, I saw a giant butterfly made of colored lights move across the wall. I suddenly realized that those flashing lights were creating images which one could only see by following them a certain way with the eyes.
For the rest of our visit, I tried to get my family to see the images. "Look, now it's a fish! Look, now it's an image of a school bus! Can you see it? Look, now it's a scrolling message, it says, "If you can read this, tell a friend how to read this...."

My wife looked at me, convinced I was making it all up. "All I see are flashing lights," she said. I could sense she was getting annoyed at the "trick" she thought I was playing on her.

I was fascinated by the lights, even more so because I've taken an interest in optical illusions lately. A few weeks ago, I made my own stereogram (similar to the one this guy made) and handed it out to the members of my congregation on Christmas day. "The stereogram in your hands," I told my parishioners," becomes a 3-D image if you look at it the right way. You may not see it at first. You have to train your eyes and your mind to see it.... In the same way, Jesus is in the world; but the world does not always see him. Again, we have to train ourselves in order to 'see.'"

At the gift shop, I bought a book on optical illusions. Then we left, and headed to Pier 39, where we enjoyed lunch, watched the sea lions, and had ice cream. And, eating their ice cream, Ethan and Tristan were, in fact, very happy.