THE PRIMACY OF DOUBT

An exploration of the amorphous concept of uncertainty, “an essential part of the human condition.”

Uncertainty is another name for chaos, a fascinating concept largely unknown until the 1950s. Palmer, a professor of physics at Oxford, works hard to explain it to lay readers. He begins with Newton’s law of gravity, which can predict the Earth-sun orbit precisely into the distant future but only works with two gravitating bodies. After three centuries of searching for a formula to predict the positions of three or more, French physicist Henri Poincare proved that “no formula exists.” Planetary orbits are “chaotic.” Like weather or stock prices, “the system appears reasonably predictable until, out of the blue, it behaves unpredictably”—which means that it’s not impossible that the Earth will one day wander out of its orbit. One of Palmer’s main characters is meteorologist and mathematician Edward Lorenz (1917-2008). Before Lorenz, scientists believed that if you had enough accurate information about current conditions (temperature, wind speed, humidity), you could feed the details into a powerful computer and predict weather far into the future. Lorenz proved that this was impossible; tiny changes in initial conditions can blow up into huge errors. Chaos theory doesn’t make prediction impossible, only erratic over the short term. Weather forecasts have grown more accurate, but they’re now expressed in percentages. Palmer believes that embracing uncertainty might explain phenomena considered hopelessly complex, and he illustrates his points with densely argued chapters on financial crashes, war, climate change, pandemics, and brain function. The author is a fluid writer, but the sections on complicated areas such as fractal geometry and quantum uncertainty may overwhelm readers unfamiliar with college physics and calculus. They should prepare by reading James Gleick’s Chaos, still in print after 35 years—and which Palmer calls “masterful.”

Read Gleick first and then turn to this informative, ingenious book.