History as a giant data set [The Guardian, 12 Nov 2019]
In 2010, a letter in the scientific journal Nature warned that a coming decade of dazzling technological progress risked being unravelled by mounting global political instability. This turmoil, the writer predicted, was due to peak in the US and western Europe around 2020. Human societies go through predictable periods of growth, during which the population increases and prosperity rises. Then come equally predictable periods of decline. These “secular cycles” last two or three centuries and culminate in widespread unrest – from worker uprisings to revolution.

The writer was biologist Peter Turchin, who warned that in recent decades a number of worrying social indicators – such as wealth inequality and public debt – had started to climb in western nations, indicating societies were approaching a period of upheaval. Turchin had previously used sophisticated maths to show how the interactions of predators and prey produce oscillations in animal populations in the wild. After answering all the ecological questions that interested him, he found himself drawn to history: could the rise and fall of human societies be captured by his variables and equations? Could calculating the patterns and cycles of the past lead us to an objective version of history – and help us prevent a looming crisis?