This project was no longer mathematics; it was engineering. - Arthur C. Clarke

Maybe it’s a mark of a maturing culture, do you think, that secrets aren’t kept, that truth is told, that things are talked out?

"Bowman was aware of some changes in his behavior patterns; it would have been absurd to expect anything else in the circumstances. He could no longer tolerate silence; except when he was sleeping, or talking over the circuit to Earth, he kept the ship's sound system running at almost painful loudness. / At first, needing the companionship of the human voice, he had listened to classical plays — especially the works of Shaw, Ibsen, and Shakespeare — or poetry readings from Discovery's enormous library of recorded sounds. The problems they dealt with, however, seemed so remote, or so easily resolved with a little common sense, that after a while he lost patience with them. / So he switched to opera — usually in Italian or German, so that he was not distracted even by the minimal intellectual content that most operas contained. This phase lasted for two weeks before he realized that the sound of all these superbly trained voices was only exacerbating his loneliness. But what finally ended this cycle was Verdi's Requiem Mass, which he had never heard performed on Earth. The "Dies Irae," roaring with ominous appropriateness through the empty ship, left him completely shattered; and when the trumpets of Doomsday echoed from the heavens, he could endure no more. / Thereafter, he played only instrumental music. He started with the romantic composers, but shed them one by one as their emotional outpourings became too oppressive. Sibelius, Tchaikovsky, Berlioz, lasted a few weeks, Beethoven rather longer. He finally found peace, as so many others had done, in the abstract architecture of Bach, occasionally ornamented with Mozart. / And so Discovery drove on toward Saturn, as often as not pulsating with the cool music of the harpsichord, the frozen thoughts of a brain that had been dust for twice a hundred years."

Space can be mapped and crossed and occupied without definable limit; but it can never be conquered. When our race has reached its ultimate achievements, and the stars themselves are scattered no more widely than the seed of Adam, even then we shall still be like ants crawling on the face of the Earth. The ants have covered the world, but have they conquered it — for what do their countless colonies know of it, or of each other? So it will be with us as we spread out from Earth, loosening the bonds of kinship and understanding, hearing faint and belated rumors at second — or third — or thousandth hand of an ever dwindling fraction of the entire human race. Though the Earth will try to keep in touch with her children, in the end all the efforts of her archivists and historians will be defeated by time and distance, and the sheer bulk of material. For the numbers of distinct human societies or nations, when our race is twice its present age, may be far greater than the total number of all the men who have ever lived up to the present time. We have left the realm of comprehension in our vain effort to grasp the scale of the universe; so it must ever be, sooner rather than later.