"The sort of SF that relies directly on state-of-the-art stuff like micro-black-holes or Piltdown Man is the only kind that really suffers when scientists move the goalposts."
"A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it."
— Max Planck
"The future is a moving target."
"Our love is like a brontosaurus. Recognized as a mistaken combination long ago, lingering only out of misplaced affection for a mistaken past."
"Once a man has changed the relationship between himself and his environment, he cannot return to the blissful ignorance he left. Motion, of necessity, involves a change in perspective."
— Commissioner Pravin Lal - "A Social History of Planet", Sid Meierís Alpha Centauri
In those white-heat-of-technology days every astronomy book had an early chapter which was invisibly entitled "Let's have a good laugh at the beliefs of those old farts in togas" (reality in those days being something called Zeta, a nuclear reactor that would soon be producing so much electricity we'd all be paid to use it).
Terry Pratchett, The Discworld Companion
"The advance of science does kill some romance. In 1950, it was still possible to think of a barely habitable Mars. There was still the possibility of canals, of liquid water, of a high civilization either alive or recently dead — at least there was no definite scientific evidence to the contrary."
— Isaac Asimov, on A.E. van Vogt's Enchanted Village