Around the time of the Terran Caesar Augustus, a Martian artist had been composing a work of art. It could have been called a poem, a musical opus, or a philosophical treatise; it was a series of emotions arranged in tragic, logical necessity. Since it could be experienced by a human only in the sense in which a man blind from birth might have a sunset explained to him, it does not matter which category it be assigned.
Robert A. HeinleinYou got the impression that he never needed to sleep - just ten-thousand-mile checkups and dust him off occasionally.
Robert A. Heinlein