A precondition for being a science fiction writer other than an interest in the future is that, an interest - at least an understanding of science, not necessarily a science degree but you must have a feeling for the science and its possibilities and its impossibilities, otherwise you're writing fantasy. Now, fantasy is also fine, but there is a distinction, although no one's ever been able to say just where the dividing lines come.
Arthur C. ClarkeThey will have time enough, in those endless aeons, to attempt all things, and to gather all knowledge... no Gods imagined by our minds have ever possessed the powers they will command... But for all that, they may envy us, basking in the bright afterglow of Creation; for we knew the Universe when it was young.
Arthur C. ClarkeThere's a passage about 'rivers of molten rock that wound their way... until they cooled and lay like twisted dragon-shapes vomited from the tormented earth.' That's a perfect description: how did Tolkien know, a quarter century before anyone ever saw a picture of Io? Talk about Nature imitating Art.
Arthur C. Clarke