THE future is radically unpredictable. It’s unpredictable because we can only track change. We can’t predict futures. Humans can do a little better than other species in predicting futures, but because of the rate of change of technology in human society, constantly throwing out new problems because of the complexity of the social changes that are occurring, then predicting the future becomes extremely hard.
"That is why I say in many respects it’s radically unpredictable. What I do insist is that we have the freedom to make choices about it … but we don’t have infinite flexibility in making those choices …we are constrained by our evolutionary past, by our biological givens — none of us can walk on water, any more than we can grow wings." Steven Rose in The two Steves debate 
"Towards the end of the 19th century, the famous physicist William Thomson, more commonly known as Lord Kelvin, proclaimed the end of physics. Despite the silliness of declaring a field moribund, particularly one that had been subject to so many important developments not so long before Thomson’s ill-fated pronouncement, you can’t really fault the poor devil for not foreseeing quantum mechanics and relativity and the revolutionary impact they would have. Seriously, how could anyone, even someone as smart as Lord Kelvin, have predicted quantum mechanics?" Lisa Randall, Physicist, Harvard University 
"I used to think you could … In Profiles of the Future, Arthur C Clarke made it seem so easy. "
And so did all those other experts who confidently predicted the paperless office, the artificial intelligentsia who for decades predicted ‘human equivalence in 10 years’, the nanotechnology prophets who kept foreseeing major advances toward molecular manufacturing within 15 years, and so on.
"Mostly, the predictions of science and technology types were wonderful: space colonies, flying cars in everyone’s garage, the conquest (or even reversal) of ageing. (There were of course the doomsayers, too, such as the population-bomb theorists who said the world would run out of food by the turn of the century.)
"But at last, after watching all those forecasts not come true, and in fact become falsified in a crashing, breathtaking manner, I began to question the entire business of making predictions.
"And then I finally decided that I knew the source of this incredible mismatch between confident forecast and actual result. The universe is a complex system in which countless causal chains are acting and interacting independently and simultaneously (the ultimate nature of some of them unknown to science even today).
"There are in fact so many causal sequences and forces at work, all of them running in parallel, and each of them often affecting the course of the others, that it is hopeless to try to specify in advance what’s going to happen as they jointly work themselves out.
"Formerly, when I heard or read a prediction, I believed it. Nowadays I just roll my eyes, shake my head, and turn the page." Ed Regis, Science Writer, from an article at www.edge.org