One theory which can no longer be taken very seriously is that UFOs are interstellar spaceships.
Arthur C. ClarkeAfter their encounter on the approach to Jupiter, there would aways be a secret bond between them---not of love, but of tenderness, which is often more enduring.
Arthur C. ClarkeThe intelligent minority of this world will mark 1 January 2001 as the real beginning of the 21st century and the Third Millennium.
Arthur C. ClarkeScience fiction seldom attempts to predict the future. More often than not, it tries to prevent the future.
Arthur C. ClarkeBefore you become too entranced with gorgeous gadgets and mesmerizing video displays, let me remind you that information is not knowledge, knowledge is not wisdom, and wisdom is not foresight. Each grows out of the other, and we need them all.
Arthur C. ClarkeIt is a good principle in science not to believe any 'fact'---however well attested---until it fits into some accepted frame of reference. Occasionally, of course, an observation can shatter the frame and force the construction of a new one, but that is extremely rare. Galileos and Einsteins seldom appear more than once per century, which is just as well for the equanimity of mankind.
Arthur C. Clarke