The first modern digital computers were developed in the 1940s for military purposes that arose during World War II. These computers filled entire rooms, and at rates of a few thousand calculations per second, they took hours to perform complex mathematical operations. In the 1970s, the first personal computers were sold. Fitting on a desktop, they were exponentially faster and more powerful than the computers that had once filled large rooms. They were also affordable to individual consumers, making it possible for many people to use them for personal, business, and academic needs. By the mid-1990s, laptop computers capable of millions of calculations per second had been developed. Currently, nearly half of American homes have a personal computer, and businesses have come to rely on computers for nearly every function. Futurists prognosticate that computers will continue to become smaller and more powerful and that they will be...