'Our home galaxy, again, with its hundred billion suns,' repeated the commentator, 'most of them are little suns like our own-too small to be visible on this scale. All those you see here are giants; ours is only a dwarf, despite its overwhelming importance to us.
'And of those hundred billion suns, large and small– how many shine upon worlds that carry life? Perhaps most of them, for matter has the same properties throughout the universe. We know that life arose independently on Earth and Mars. we believe that it arises automatically on all worlds that are not too hot or cold, that have the common elements of oxygen and carbon and hydrogen, and that are bathed by sunlight for a few billion years.
'Yet even if life is common, intelligence may be rare; in the long story of Earth, it has evolved only once. Nevertheless, there may be millions of advanced cultures scattered throughout the Galaxy-but they will be separated by gulfs that light itself takes years to span.'
Two arrows appeared, aimed at stars so close together in the sparsely populated outer arms of the Galaxy that they seemed to be neighbors.
'If this was our Sun, and we sent a radio signal to a planet circling this nearby one, it would take a thousand years for the reply…. Or, to put it in another way, we might expect an answer now, if the message left our world around the birth of Christ…. And this would be a conversation with one of the closest of our galactic neighbors.
'Yet even if it takes thousands of years to travel from star to star, a really advanced race might attempt the feat. It could send robot ships exploring for it-as Man has already sent his robots ahead of him to explore the Moon and planets.'
There were shots of ungainly space probes-some familiar, others obviously imaginary-drifting across the stars, peering down at passing worlds with their television eyes.
'Or they might build huge space arks-mobile planetoids which could travel between the stars for centuries, while generation after generation lived and died upon them….
'Or they might hibernate, or be frozen in the changeless sleep of suspended animation, to be awakened by robots when their age-long journey neared its end….
'Even these are not the only possibilities. A very advanced race might be able to build ships that could attain almost the speed of light. According to Einstein, no material object can travel faster than this; it is the natural built-in speed limit of our universe. However, as we approach this speed, time itself appears to slow down. A space traveler might fly to a distant star in what, to him, appeared to be only a few months-or even a few hours.
'But only to him. When he returned from his destination, he would find that years or centuries had passed, that all his friends were dead, and, perhaps, that his very civilization had vanished. That would be the price of stellar exploration-trading Time for Space, with no possibility of refund. Yet the price might be attractive, to creatures whose lives are much longer than ours.
'Finally-perhaps Einstein's theory, like so many theories in the past, does not tell the whole truth. There may be subtle ways of circumventing it, and so exceeding the speed of light. Perhaps there are roads through the universe which we have not yet discovered-shortcuts through higher dimensions. 'Wormholes in Space,' some mathematicians have called them; one might step through such a hole-and reappear instantaneously, a thousand light-years away.
'But even if this is true-and most scientists think it pure fantasy-the exploration of the universe will still require unimaginable ages. There are more suns in the whole of space than there are grains of sand on all the shores of Earth; and on any one of those grains, there may be civilizations that will make us look like primitive, ignorant savages.
'What will we say to the peoples of such worlds, when at last we meet? And what will they say to us?'
'Thank you, Victor,' said Manning when the screen blanked out and the red light in the dubbing room went off. 'I knew you'd do it. Don't worry about the fluffs– we'll fix them. Anyway-what did you think of it?'
'Not bad-not bad. But I wish you hadn't put in that nonsense at the end.'
'Eh? What nonsense?'
'Higher dimensions, wormholes in space, and all that rubbish. That's not science; it's not even good science fiction. It's pure fantasy.'
'Well, that's exactly what the script said '
'Then why bring it in? Whose bright idea was it?'
'One Dr. Heywood Floyd's, if you want to know. I suggest you take it up with him.'
Kaminski really meant it, but somehow the matter slipped his mind. There was so much work to do, so much to learn, that it was months before he thought of it again.
And then it was far, far too late.
ANCESTRAL VOICES
The ape-man stood on a low, rocky hill, grasping a pointed stone and looking out across a dusty African plain. Overhead, the sky was cloudless, and a hot sun baked the yellowing grass of the savannah and the stunted trees which provided the only shade. In the middle distance, a small herd of gazelles was browsing, watched intently by a saber-toothed tiger crouching in the scrub.
There were more ape-men-about a dozen of them– scattered over the crown of the little hill. Propped up against a large boulder, one female was nursing her baby; not far away, two juveniles were quarreling over a hunk of meat-all that was left of some small dismembered animal. One bent and gray-haired male was trying to suck the marrow from a cracked bone; another was curled up asleep; two females were grooming each other for lice; and yet another male was hunting through a pile of dried bones in search of future weapons.
'It's a beautiful model,' said Bowman at last, when he and his two companions had looked their fill.
'Thank you,' answered the curator of Anthropology. 'It's as accurate as humanly possible several years of work went into it.'
Dr. Anna Brailsford was a striking, dark-haired woman in her early forties, who seemed much too vivacious to have devoted her life to fossils. Though she was a famous explorer and veteran of many expeditions, she had lost none of her femininity; it was hard to believe that she was one of the world's leading authorities on early Man.
'So these,' said Phillip Goode, Bowman's understudy, 'are the characters the pyramid-makers would have met, if they landed on Earth three million years ago?'
'Not necessarily. It depends on the thoroughness of their investigation. Australopithecus was probably not very common; he might easily have been overlooked among the elephants and giraffes and other more conspicuous animals. In fact, he wasn't even the most impressive of the primates. To a casual visitor, he might have seemed just another ape.'
It was rather difficult, thought Bowman, to take so detached a view. His great-to-the-hundred– thousandth grandfather was not a very prepossessing sight, but there was a wistful sadness about the hairy, no-longer-quite animal face staring at him through the glass of the diorama. He was not ashamed to admit kinship with his remote ancestor across the unimaginable ages that sundered them. 'I rather doubt,' he said dryly, 'that creatures landing on Earth back in the Pleistocene would have been casual visitors. And this is one of the things we wanted to discuss with you-their motivations.'
'Well, I can only tell you how I'd behave, in the same circumstances. I'd note that Earth was teeming with advanced life forms, but that none of them had developed high intelligence. However, I'd probably guess-I might even be able to predict, with the knowledge I'd undoubtedly have-that intelligence would arise in a few million years.
'So I'd leave behind some intelligence monitors-or, better still, civilization detectors. I might put some of them on Earth, though I'd realize that they would probably be destroyed or buried before they had a chance to operate. But the Moon would be an ideal spot for such a device especially if I was only interested in civilizations that had reached the space-faring stage. Any culture still planet-bound might be too primitive to concern me.'
'So you're in favor of the fire-alarm theory, as we call it, to explain TMA-1?'
'Yes-it seems very plausible. But perhaps it's too plausible. Human motivations vary so much that any attempt to analyze wholly alien behavior must be pure guesswork.'
'But guesswork is all we have to go on for the present. We're trying to think of every possibility that may arise, when and if we do catch up with the creatures who built TMA-1.'
