The family must be waiting, there in the reception lounge; and now, with only seconds before the moment of reunion, Duncan felt a reluctance to face the whole Makenzie clan. He let the other travelers go hurrying past him, while he stood irresolutely, trying to pluck up his courage and clutching his precious bundle awkwardly to his chest. Then be moved forward, under the archway, and out onto the ramp.

There were so many of them! Malcolm and Colin, of course, Marissa, more beautiful and desirable than even in his most restless dreams, now free of

Calindy forever; Clyde and Carline-could she really have grown so much, in so short a time? And at least twenty nephews and nieces whose names he knew as well as his own, but just couldn’t recall at the moment.

No-it was impossible! But there she was, standing a little apart from the others, leaning heavily on her cane, yet otherwise completely

unaltered since he had 300 last seen her on the cliffs of Loch Hellbrew. Much else had changed indeed if Grandma Ellen had retamed to Oasis for the first time in fifty years.

As she saw Duncan’s astonished gaze, she gave a barely perceptible smile.

It was more than a greeting; it was a signal of reassurance. She already knows, thought Duncan. She knows and approves. When the full fury of the

Makenzies breaks upon my head I can rely on her…. There flashed into his mind an old Terran phrase, whose origin he had long ago forgotten: the Moment of Truth. Well, here it was They all crowded eagerly around him as he drew back the shawl. For an instant only he felt regret; perhaps he should have given some warning. No, it was better this way. Now they would learn that he was his own man at last, no longer a pawn of others-however much he might owe to theta, however much he might be part of them.

The child was still sleeping, but normally now, not in the, electronic trance that had protected it on the long voyage from Earth. Suddenly it threw out a chubby arm, and tiny fingers gripped Duncan’s hand with surprising strength. They looked like the pale white tentacles of a sea anemone against the dark brown of Duncan’s skin.

The little head was still empty even of dreams, and the face was as void and formless as that of any mont hold baby. But already the smooth, pink scalp bore an unmistakable trace of hair-the golden hair that would soon bring back to Titan the lost glories of the distant Sun.

ACKNOWLEDGMENTS AND NOTES

my first thanks should go to Truman Talley, who in the early ‘50’s made what was then (and for that matter still is) a most generous offer for this book, on the strenath of the title and one conversation. I have often wished that I could remember what I said then; it might have saved me much trouble, twenty years later. I now have no idea if this book bears the slightest resemblance to that early concept, but “Macls” initial encouragement kept me from abandoning it.

Like many other addicts, I was introduced to polyominoes by Martin

Gardner’s Scientific American Book of Mathematical Puzzles and Diversions, which, however, fiendishly refrains from giving the solution to the 20 X 3 rectangle. In his definitive book Polyominoes, Solomon W. Golomb takes mercy on his readers. In the hope of preventing a few nervous breakdowns,

I reproduce his answer herewith:

UXPILNFTWYZV

Anyone who wishes to construct this rectangle from the twelve pentominoes should have no difficulty in matching them with the letters they (sometimes approximately) resemble. It is easy to see that the second of the (only) two solutions is obtained by rotating a seven-element central portion.

Dr. Golomb, who is now professor of Electrical

Engineering and Mathematics at the University of

Southern California, has also invented an ingenious game called Pentominoes@ (distributed in North

America by Hallmark Cards and in Europe by Zimpfer

Puzzles). It has more openings than chess. In an earlier version of 2001: A Space Odyssey, Stanley Kubrick shot Hal playing this game against the astronauts.

I am indebted to Dr. Robert Forward of the Hughes Research Laboratory,

Malibu, for introducing me to the fascinating concept of mini black holes, and for making such encouraging noises about the somewhat outrageous propulsion system of S. S. Sirius that I am almost inclined to patent it…. Dr. Grote Reber, the father of radio astronomy and builder of the world’s first radio telescope, started me thinking about the extent of the heliosphere and, its possible consequences. I am grateful for his comments on cutoff frequencies, but he is in no way responsible for my wilder extrapolations of his ideas. Dr. Adrian Webster, of Cavendish Laboratory’s

Mullard Radio Astronomy Observatory, also gave much vital information, and he too is not to be blamed for my use of it.

I am especially indebted to Dr. Bernard Oliver, vice-president and director of research of Hewlett Packard not only for hospitality at Palo Alto but also for an advance copy of the Project CYCLOPS Design Study NASA Ames CR 114445), which he directed. And I hope Barney will forgive me for the assumption-which in fact I regard as highly improbablo–that CYCLOPS would not have detected intelligent signals, even after two hundred years of operation.

Indignant antenna designers who feel that Argus would not work as specified are invited to contemplate ABM search radars, and to Think Big. All I will say in self-defense is that the Argus elements would be superconducting, active, and divided into many switchable subsections, perhaps with cross-connections between the “spines.” I leave minor practical details (as in the case of the Asymptotic Drive) as an exercise for the student.

The “exasperated” remark in Chapter 21 was made to me at a NASA conference by Professor Neil Armstrong in July 1970. I hope it is the last word on some famous first words.

I am deeply grateful to my old friend William Mac

Quitty, producer of A Night to Remember, for much material concerning the Titanic-including the menu in Chapter 27. Collectors of unlikely

coincidences may be interested to know that just three hours after I had decided to incorporate it in the text, I read in the May 1974 Skin Diver that the

Titanic Enthusiasts of America had served this menu at their Annual

Dinner…. Some readers may feel that the coincidences-or “correspondences”-that play a key part in this story are too unlikely to be plausible. But they were, in fact, suggested by far more preposterous events in my own life; and anyone who doubts that this sort of thing can happen is referred to Arthur

Koestler’s The Roots of Coincidence. I read this fascinating book only after completing Imperial Earth, though that fact itself now seems somewhat improbable to me.

Even more improbable is the fact that when, on July 24, 1975, I appeared as a witness before the House of Representatives Subcommittee on Space Science (in the very building libeled and demolished in Chapter 33!), I was able to quote extensively from Duncan’s address to Congress in Chapter 41. Thus the

House of Representatives’ hearings now contain extracts from the

Congressional Record for July 4, 2276, which should cause confusion among future historians.

The curious acoustic behavior of the spiny sea urchin, Diadema setosum, was observed by me on Unawatuna Reef, off the south coast of Sri Lanka. I have never seen this recorded elsewhere, so it may be my one original contribution to marine biology.

Finally, my speculations about conditions on Titan were triggered by a series of papers that Dr. Carl Sagan was good enough to send me. Needless to say, I am also indebted to Carl for many other stimulating ideas, which any properly designed universe would be very foolish to ignore. “For if not true, they are well imagined…