The crossing of space ... may do much to turn men's minds outwards and away from their present tribal squabbles. In this sense, the rocket, far from being one of the destroyers of civilisation, may provide the safety-value that is needed to preserve it.
Arthur C. ClarkeIt was a pity that there was no radar to guide one across the trackless seas of life. Every man had to find his own way, steered by some secret compass of the soul. And sometimes, late or early, the compass lost its power and spun aimlessly on its bearings. Alan Bishop
Arthur C. ClarkeScience fiction does not attempt to predict. It extrapolates. It just says, "What if?" not what will be? Because you can never predict what will happen, particularly in politics and economics. You can to some extent predict in the technological sphere - flying, space travel, but even there we missed badly on some things, like computers. No one imagined the incredible impact of computers, even though robot brains of various kinds but the idea that one day every house would have a computer in every room and that one day we'd have computers built into our clothing, nobody ever thought of that.
Arthur C. ClarkeOne orbit, with a radius of 42,000 kilometers, has a period of exactly 24 hours. A body in such an orbit, if its plane coincided with that of the Earth's equator, would revolve with the Earth and would thus be stationary above the same spot on the planet. It would remain fixed in the sky of a whole hemisphere ... [to] provide coverage to half the globe, and for a world service three would be required, though more could be readily utilized. (1945) [Predidicting geosynchronous communication satellites]
Arthur C. Clarke