A long tradition explains technological change as recombination. Within this tradition, this Element develops an innovative combinatorial model of technological change and tests it with 2,000 years of global GDP data and with data from US patents filed between 1835 and 2010. The model explains 1) the pace of technological change for a least the past two millennia, 2) patent citations and 3) the increasing complexity of tools over time. It shows that combining and modifying pre-existing goods to produce new goods generates the observed historical pattern of technological change. A long period of stasis was followed by sudden super-exponential growth in the number of goods. In this model, the sudden explosion of about 250 years ago is a combinatorial explosion that was a long time in coming, but inevitable once the process began at least two thousand years ago. This Element models the Industrial Revolution as a combinatorial explosion.

In the countryside of Oregon is a beautiful golf course called Diamond Woods. A family owns the golf course and work together to keep things running smoothly. Up the hill behind the golf course live farm animals and woods animals, and things aren't going so smoothly. The farm animals have names, but the woods animals don't. All the animals are very different. But when farm animals venture into the woods, they sometimes never come back. "The farm animals are real, with their observed personalities and behaviors integrated into the story. Very creative. A delightful read." - Tim C. Leedom - Author, editor and film-writer, Manoa Valley Publishing Illustrated by the illustrator for the grandson of the author of the Wizard of Oz.