It worked, but all of our plans, carefully put in place over several weeks, had gone out the window. We live in an uncertain world, and even when you think you know what’s going to happen, the universe can bite you.Excerpted from Do Dice Play God: The Mathematics of Uncertainty, by Ian Stewart, emeritus professor of mathematics at the University of Warwick. Buy on Amazon.
On the other hand, uncertainty isn’t always bad. We like surprises, as long as they’re pleasant ones. Many of us enjoy a flutter on the horses, and most sports would be pointless if we knew at the start who was going to win. Some prospective parents are keen not to be told the sex of the baby. Most of us, I suspect, would prefer not to know in advance the date of their own death, let alone how it will occur. But those are exceptions. Life is a lottery. Uncertainty often breeds doubt, and doubt makes us feel uncomfortable, so we want to reduce, or better still eliminate, uncertainty. We worry about what will happen. We look out for the weather forecast, even though we know that weather is notoriously unpredictable and the forecast is often wrong.
Human affairs have always been messy, but even in science, the old idea of nature obeying exact laws has given way to a more flexible view. We can find rules and models that are approximately true (in some areas "approximate" means "to 10 decimal places"; in others it means "between 10 times as small and 10 times as large") but they’re always provisional, to be displaced if and when fresh evidence comes along. Chaos theory tells us that even when something does obey rigid rules, it may still be unpredictable. Quantum theory tells us that deep down at its smallest levels, the universe is inherently unpredictable.
Uncertainty isn’t just a sign of human ignorance; it’s what the world is made of.
And sometimes uncertainty can actually be useful. Many areas of technology deliberately create controlled amounts of uncertainty, in order to make devices and processes work better. Mathematical techniques for finding the best solution to an industrial problem use random disturbances to avoid getting stuck on strategies that are the best compared to near neighbors, but not as good as more distant ones. Random changes to recorded data improve the accuracy of weather forecasts. Space missions exploit chaos to save expensive fuel.