This book is about the future of technology. In it we will examine some of the many recent developments in a few key fields and try, in a limited way, to forecast where they will take us in the next fifteen years or so.

If that sounds like a modest goal, it's not. Technology is the dominant force of our time and probably of all time to come. It appears in more varieties than we can count. It changes so rapidly that no scientist or engineer can keep up with his own field, much less with technology in general. It permeates and shapes our lives at every turn. We live in technology as fish live in the sea, and we have only a little better chance of forecasting the details of its changes.

Yet the task is well worth undertaking. Whatever hints we can glean about the future will help us prepare for the changes to come. Modest forecasts, evidence of trends, a few concrete developments to be expected all are better than no warning at all. And though technology has made the present much less stable than the past, and surely will make the future more turbulent still, there is good reason to hope that our lives, in sum and on average, will be better as a result. In an age of uncomfortable challenges, this is reassurance we all can use.

For an idea of what is to come—in magnitude if not in specifics—look to the past. In the last ninety years, the world has shrunk, while human experience has expanded almost beyond the recognition of those who grew up in our grandparents' generation.

A century after America's founders conceived their agrarian democracy, nearly all their descendents still lived on small farms. Since World War I, technology has extracted us from behind horse-drawn plows and plugged us into assembly lines and offices. Today it is removing many of us from offices and letting us work at home or compelling us to work on the road.

As recently as 1920, the average American baby could expect to live only fifty-four years. By the early 1990s, average life expectancy in the United States had climbed to seventy-five years, seventy-two for men and neatly seventy-nine for women. In the next twenty years, life expectancy may well rise again, even more steeply. This time it will climb, not only for the newborn but for those already well into adulthood.

In transportation and communications, the changes have been even more pronounced. As recently as World War two, the average American lived and died within 38 miles (61 kilometers) of his birthplace. For New Yorkers, the radius was only 17.5 miles (28 kilometers), as far as the subway ran. Information from the outside came by newspaper, radio, or word from the traveler's mouth; it moved intermittently and often arrived only after long delay. In 1945, when the first atomic bomb fused the sand of Alamogordo, New Mexico, the shot was not heard around the world; rumors of a massive explosion in the desert were easily contained. Only a half century later, someone born in Massachusetts is more likely than not to attend college in Chicago, find a job in Seattle, vacation in Mexico, and retire in Florida. News from London, Moscow, Sarajevo, and Pyongyang arrives instantly on CNN and, for growing numbers of people, on personal computers fed by the Internet. From our offices in suburban Virginia and rural New Hampshire, Paris, Singapore, Buenos Aires , and Sydney are all as close as Washington and Boston, none more distant than the few steps to the computer. Around the globe, we will spend the rest of our lives finding things to say to people we will never meet in person. Thus far, shared interests have proved easy to find.