When our familiar patterns face change

Back in fifth grade when studying "world" history, an astonishing revelation came to me: People didn't always use crop rotation.

It sounds mundane, I know. But the notion that you have to switch which plants grow in your field from year to year just came naturally to this farm kid. One year corn towered over the field behind our house, by late summer blocking the long vista to the woods along the creek; the next year, it was squat soybeans then the following spring alfalfa or oats, which upon reaching maturity undulated like a sea against the shore of our lawn.

Medieval Europeans figured out this simple system of renewing the soil because some crops pull large amounts of nutrients from the dirt. It transformed their lives. Before then, serfs grew whatever they liked on the land and let livestock graze it when fallow.

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Crop rotation marks cycles that can last three or four years. It's a subtle symbol of tradition's strength in rural areas. All of us recognize monthly moon phases and the annual play of seasons, but crop rotation goes beyond that. The corn behind my house rose the summer before third grade, the one before seventh and the one before 11th. Mathematicians may delight that those are prime numbers (meaning they're only divisible by two numbers). Every year, the "largest" prime is found; so far, the largest is 6,320,430 digits long and was determined just last year.

People didn't always know about prime numbers, either. Euclid "discovered" them in 350 B.C. But they also altered people's lives, though more ours than the ancients. We use them in computing and cryptography.

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Much of life, interestingly, is a puzzle to be solved. As toddlers we must grasp language. As school children we tussle with social hierarchies. By our teen years, it's romance and the other gender. In adulthood, it's the politics of the work place. In the farm field, it's outguessing the weather.

For each of these, we turn to models. What does the older sibling, classmate or colleague do? We plow through experts' books and hear consultants speak. We gaze up at the sky and know that certain clouds and the feel of the wind from a certain direction signal rain.

Some despair this fact of existence - and our puzzles can at times be frustrating to the point that one turns red. Though the rest of the world moves along, fear of change rules some people's day.

Such fright isn't necessarily of the future but of the repudiation of what we've become comfortable with. Once the puzzle seems to make sense, changing means new solutions must be learned. I know. Corn should have grown behind my house when I was a junior in college because that's the pattern I'd learned.

But that year my father changed up the crop rotation and the field lay fallow. The soil needed more nourishment. That wasn't too difficult to grasp. After all, there always is one larger prime number to discover.

(originally published Dec. 5, 2004)