2009-04-05

Newton's 1st

I've always liked math. There are few greater evidences to the underlying order of the universe than the fact that so much of it can be eloquently explained by mathematics. It's too bad that everyone questions the applicability of their math classes. Math is problem solving. Life is also problem solving; adjusting for variables, determining relationships, solving for unknowns.

Subconsciously, we do really complex math all the time without even thinking about it. Even the simplest motion requires the calculation of inertia, accelerations, centers of mass. A quarterback heaving a football 30 yards to a receiver on a fade route is solving the equivalent of a physics final in a matter of a split second.

Sometimes, though, we get the math wrong. Sometimes the equations have too many unknowns, and we have to guess... Snowboarding last week as an example. I was enjoying a wonderful spring ski day. The sun was out, but the snow still had good feel. Halfway down the run, we happened upon a middle aged couple skiing somewhat slowly down the trail. She was following in his tracks, about 5 seconds behind, such that when one was on the right side of the trail, the other was on the left, a lot like two particles on a sine wave.

And thus begins the math. Visibility good? Check. Pass her or him? Him, he looks more predictable. Where to pass? My friend is to my left, I should go right. When to pass? About 3pi/2, where he's at a local minimum and turning to his left. Slope grade sufficient to gain passing speed? Check. Go to pass? Check.

Well, he didn't turn left. I realize all too late that this was more of statistical quantum mechanics problem than a classical mechanics one. As we collide, Newton's first law takes over. For a second we're just a mass of limbs and equipment, and then I'm cartwheeling down the mountain. (I've actually found cartwheeling to be a pretty good way to avoid injury and makes the crash a little more entertaining for the spectators.)

He comes to rest about 10 feet above me, fit to be tied, but physically unharmed. In a situation like this, when your math skills have failed you, you tend to feel pretty sheepish. The tongue lashing was unnecessary, but not undeserved. I was a little surprised neither of them seemed to care if I was okay, but I'll get over it. What I can't get over, though, was slow-skier's wife accusing me of not paying attention. Though guilty of many things, not paying attention was not one them. My math was just off.

But that's the thing about real life math. You can't account for all of the variables. And if you did wait until the equation was completely solvable, the moment would surely pass. That's the hardest math of all, making a decision despite the unknowns. Even though it doesn't turn out the way you expected, that doesn't necessarily make it a bad decision. Next time I'll have to show my work so I can get partial credit.