Recently, the computer has touched off a storm of fresh ideas about man as an interacting part of larger systems, about his physiology, the way he learns, the way he remembers, the way he makes decisions. Virtually every intellectual discipline from political science to family psychology has been hit by a wave of imaginative hypotheses triggered by the invention and diffusion of the computer – and its full impact has not yet struck. And so the innovative cycle, feeding on itself, speeds up.

If technology, however, is to be regarded as a great engine, a mighty accelerator, then knowledge must be regarded as its fuel. And we thus come to the crux of the accelerative process in society, for the engine is being fed a richer and richer fuel every day.

The rate at which man has been storing up useful knowledge about himself and the universe has been spiraling upward for 10,000 years. The rate took a sharp upward leap with the invention of writing, but even so it remained painfully slow over centuries of time. The next great leap forward in knowledge – acquisition did not occur until the invention of movable type in the fifteenth century by Gutenberg and others. Prior to 1500, by the most optimistic estimates, Europe was producing books at a rate of 1000 titles per year. This means, give or take a bit, that it would take a full century to produce a library of 100,000 titles. By 1950, four and a half centuries later, the rate had accelerated so sharply that Europe was producing 120,000 titles a year. What once took a century now took only ten months. By 1960, a single decade later, the rate had made another significant jump, so that a century's work could be completed in seven and a half months. And, by the mid-sixties, the output of books on a world scale, Europe included, approached the prodigious figure of 1000 titles per day.

One can hardly argue that every book is a net gain for the advancement of knowledge. Nevertheless, we find that the accelerative curve in book publication does, in fact, crudely parallel the rate at which man discovered new knowledge. For example, prior to Gutenberg only 11 chemical elements were known. Antimony, the 12th, was discovered at about the time he was working on his invention. It was fully 200 years since the 11th, arsenic, had been discovered. Had the same rate of discovery continued, we would by now have added only two or three additional elements to the periodic table since Gutenberg. Instead, in the 450 years after his time, some seventy additional elements were discovered. And since 1900 we have been isolating the remaining elements not at a rate of one every two centuries, but of one every three years.

Furthermore, there is reason to believe that the rate is still rising sharply. Today, for example, the number of scientific journals and articles is doubling, like industrial production in the advanced countries, about every fifteen years, and according to biochemist Philip Siekevitz, "what has been learned in the last three decades about the nature of living beings dwarfs in extent of knowledge any comparable period of scientific discovery in the history of mankind." Today the United States government alone generates 100,000 reports each year, plus 450,000 articles, books and papers. On a worldwide basis, scientific and technical literature mounts at a rate of some 60,000,000 pages a year.

The computer burst upon the scene around 1950. With its unprecedented power for analysis and dissemination of extremely varied kinds of data in unbelievable quantities and at mind-staggering speeds, it has become a major force behind the latest acceleration in knowledge-acquisition. Combined with other increasingly powerful analytical tools for observing the invisible universe around us, it has raised the rate of knowledge-acquisition to dumbfounding speeds.

Francis Bacon told us that "Knowledge ... is power." This can now be translated into contemporary terms. In our social setting, "Knowledge is change" – and accelerating knowledge-acquisition, fueling the great engine of technology, means accelerating change.

Discovery. Application. Impact. Discovery. We see here a chain reaction of change, a long, sharply rising curve of acceleration in human social development. This accelerative thrust has now reached a level at which it can no longer, by any stretch of the imagination, be regarded as "normal." The normal institutions of industrial society can no longer contain it, and its impact is shaking up all our social institutions. Acceleration is one of the most important and least understood of all social forces.

This, however, is only half the story. For the speed-up of change is a psychological force as well. Although it has been almost totally ignored by psychology, the rising rate of change in the world around us disturbs our inner equilibrium, altering the very way in which we experience life. Acceleration without translates into acceleration within.

This can be illustrated, though in a highly oversimplified fashion, if we think of an individual life as a great channel through which experience flows. This flow of experience consists – or is conceived of consisting – of innumerable "situations." Acceleration of change in the surrounding society drastically alters the flow of situations through this channel.

There is no neat definition of a situation, yet we would find it impossible to cope with experience if we did not mentally cut it up into these manageable units. Moreover, while the boundary lines between situations may be indistinct, every situation has a certain "wholeness" about it, a certain integration. Every situation also has certain identifiable components. These include "things" – a physical setting of natural or man-made objects. Every situation occurs in a "place" – a location or arena within which the action occurs. (It is not accidental that the Latin root "situ" means place.) Every social situation also has, by definition, a cast of characters – people. Situations also involve a location in the organizational network of society and a context of ideas or information. Any situation can be analyzed in terms of these five components.

But situations also involve a separate dimension which, because it cuts across all the others, is frequently overlooked. This is duration – the span of time over which the situation occurs. Two situations alike in all other respects are not the same at all if one lasts longer than another. For time enters into the mix in a crucial way, changing the meaning or content of situations. Just as the funeral march played at too high a speed becomes a merry tinkle of sounds, so a situation that is dragged out has a distinctly different flavor or meaning than one that strikes us in staccato fashion, erupting suddenly and subsiding as quickly.

Here, then, is the first delicate point at which the accelerative thrust in the larger society crashes up against the ordinary daily experience of the contemporary individual. For the acceleration of change, as we shall show, shortens the duration of many situations. This not only drastically alters their "flavor," but hastens their passage through the experiential channel. Compared with life in a less rapidly changing society, more situations now flow through the channel in any given interval of time – and this implies profound changes in human psychology.

For while we tend to focus on only one situation at a time, the increased rate at which situations flow past us vastly complicates the entire structure of life, multiplying the number of roles we must play and the number of choices we are forced to make. This, in turn, accounts for the choking sense of complexity about contemporary life.

Moreover, the speeded-up flow-through of situations demands much more work from the complex focusing mechanisms by which we shift our attention from one situation to another. There is more switching back and forth, less time for extended, peaceful attention to one problem or situation at a time. This is what lies behind the vague feeling noted earlier that "Things are moving faster." They are. Around us. And through us.