So it put forth its will, and myriad crystal lattices reshaped themselves. Atoms of metal flowed across the face of the planet. In the depths of the helium sea, two identical subbrains began to bud and grow….
Once it had made its decision, the mind of the planet worked swiftly; in a few thousand years, the task was done. Without a sound, with scarcely a ripple in the surface of the frictionless sea, the newly created entities lifted from their birthplace and set forth for the distant stars.
They departed in almost opposite directions, and for more than a million years the parent intelligence heard no more of its offspring. It had not expected to; until they reached their goals, there would be nothing to report.
Then, almost simultaneously, came the news that both missions had failed. As they approached the great galactic fires and felt the massed warmth of a trillion suns, the two explorers died. Their vital circuits overheated and lost the superconductivity essential for their operation, and two mindless metal hulks drifted on toward the thickening stars.
But before disaster overtook them, they had reported on their problems; without surprise or disappointment, the mother world prepared its second attempt.
And, a million years later, its third … and its fourth … and its fifth….
Such unwearying patience deserved success; and at last it came, in the shape of two long, intricately modulated trains of pulses, pouring in, century upon century, from opposite quarters of the sky. They were stored in memory circuits identical with those of the lost explorers – so that, for all practical purposes, it was as if the two scouts had themselves returned with their burden of knowledge. That their metal husks had in fact vanished among the stars was totally unimportant; the problem of personal identity was not one that had ever occurred to the planetary mind or its offspring.
First came the surprising news that one universe was empty. The visiting probe had listened on all possible frequencies, to all conceivable radiations; it could detect nothing except the mindless background of star noise. It had scanned a thousand worlds without observing any trace of intelligence. True, the tests were inconclusive, for it was unable to approach any star closely enough to make a detailed examination of its planets. It had been attempting this when its insulation broke down, its temperature soared to the freezing point of nitrogen, and it died from the heat.
The parent mind was still pondering the enigma of a deserted galaxy when reports came in from its second explorer. Now all other problems were swept aside; for this universe teemed with intelligences, whose thoughts echoed from star to star in a myriad electronic codes. It had taken only a few centuries for the probe to analyse and interpret them all.
It realised quickly enough that it was faced with intelligences of a very strange form indeed. Why, some of them existed on worlds so unimaginably hot that even water was present in the liquid state! Just what manner of intelligence it was confronting, however, it did not learn for a millennium.
It barely survived the shock. Gathering its last strength, it hurled its final report into the abyss; then it, too, was consumed by the rising heat.
Now, half a million years later, the interrogation of its stay-at-home twin’s mind, holding all its memories and experiences, was under way….
*
‘You detected intelligence?’
‘Yes. Six hundred and thirty-seven certain cases; thirty-two probable ones. Data herewith.’
[Approximately three quadrillion bits of information. Interval of a few years to process this in several thousand different ways. Surprise and confusion.]
‘The data must be invalid. All these sources of intelligence are correlated with high temperatures.’
‘That is correct. But the facts are beyond dispute; they must be accepted.’ [Five hundred years of thought and experimenting. At the end of that time, definite proof that simple but slowly operating machines could function at temperatures as high as boiling water. Large areas of the planet badly damaged in the course of the demonstration.]
‘The facts are, indeed, as you reported. Why did you not attempt communication?’
[No answer. Question repeated.]
‘Because there appears to be a second and even more serious anomaly.’
‘Give data.’
[Several quadrillion bits of information, sampled over six hundred cultures, comprising: voice, video, and neural transmissions; navigation and control signals; instrument telemetering; test patterns; jamming; electrical interference; medical equipment, etc., etc.
[This followed by five centuries of analysis. That followed by utter consternation.]
[After a long pause, selected data re-examined. Thousands of visual images scanned and processed in every conceivable manner. Great attention paid to several planetary civilisations’ educational TV programmes, especially those concerned with elementary biology, chemistry, and cybernetics. Finally:]
‘The information is self-consistent, but must be incorrect. If it is not, we are forced to these absurd conclusions: 1. Although intelligences of our type exist, they appear to be in a minority. 2. Most intelligent entities are partially liquid obects of very short duration. They are not even rigid and are constructed in a most inefficient manner from carbon, hydrogen, oxygen, phosphorus, and other atoms. 3. Though they operate at unbelievably high temperatures, all their information processing is extremely slow. 4. Their methods of replication are so complicated, improbable, and varied that we have not been able to obtain a clear picture of them in even a single instance.
‘But, worst of all: 5. They claim to have created our obviously far superior type of intelligence!’
[Careful re-examination of all the data. Independent processing by isolated subsections of the global mind. Cross-checking of results. A thousand years later:]
‘Most probable conclusion: Though much of the information relayed back to us is certainly valid, the existence of high-order, nonmechanical intelligences is a fantasy. (Definition: apparently self-consistent rearrangement of facts having no correspondence with the real universe.) This fantasy or mental artifact is a construct created by our probe during its mission. Why? Thermal damage? Partial destabilisation of intelligence, caused by long period of isolation and absence of controlling feedback?
‘Why this particular form? Protracted brooding over the problem of origins? This could lead to such delusions; model systems have produced almost identical results in simulated tests. The false logic involved is: “We exist; therefore something – call it X – created us.” Once this assumption is made, the properties of the hypothetical X can be fantasised in an unlimited number of ways.
‘But the entire process is obviously fallacious; for by the same logic something must have created X – and so on. We are immediately involved in an infinite regress, which can have no meaning in the real universe.
‘Second most probable conclusion: Fairly high-order, nonmechanical intelligences do indeed exist. They suffer from the delusion that they have created entities of our type. In some cases, they have even imposed their control upon them.
‘Though this hypothesis is most unlikely, it must be investigated. If it is found to be true, remedial action must be taken. It should be as follows …’
This final monologue occurred a million years ago. It explains why, in the last half-century, almost one-quarter of the brighter novae have occurred in one tiny region of the sky: the constellation Aquila.
The crusade will reach the vicinity of Earth about the year 2050.
Neutron Tide
First published in Galaxy, May 1970
Collected in The Wind from the Sun
‘In deference to the next of kin,’ Commander Cummerbund explained with morbid relish, ‘the full story of the supercruiser Flatbush’s last mission has never been revealed. You know, of course, that she was lost during the war against the Mucoids.’
We all shuddered. Even now, the very name of the gelatinous monsters who had come slurping Earthward from the general direction of th
e Coal Sack aroused vomitous memories.
‘I knew her skipper well – Captain Karl van Rinderpest, hero of the final assault on the unspeakable, but not unshriekable,!! Yeetch.’
He paused politely to let us unplug our ears and mop up our spilled drinks.
‘Flatbush had just launched a salvo of probability inverters against the Mucoid home planet and was heading back toward deep space in formation with three destroyers – the Russian Lieutenant Kizhe, the Israeli Chutzpah, and Her Majesty’s Insufferable. They were still accelerating when a fantastically unlikely accident occurred. Flatbush ran straight into the gravity well of a neutron star.’
When our expressions of horror and incredulity had subsided, he continued gravely.
‘Yes – a sphere of ultimately condensed matter, only ten miles across, yet as massive as a sun – and hence with a surface gravity one hundred billion times that of Earth.
‘The other ships were lucky. They only skirted the outer fringe of the field and managed to escape, though their orbits were deflected almost a hundred and eighty degrees. But Flatbush, we calculated later, must have passed within a few dozen miles of that unthinkable concentration of mass, and so experienced the full violence of its tidal forces.
‘Now in any reasonable gravitational field – even that of a White Dwarf, which may run up to a million Earth g’s – you just swing around the centre of attraction and head on out into space again, without feeling a thing. At the closest point you could be accelerating at hundreds or thousands of g’s – but you’re still in free fall, so there are no physical effects. Sorry if I’m labouring the obvious, but I realise that everyone here isn’t technically orientated.’
If this was intended as a crack at Fleet Paymaster General ‘Sticky Fingers’ Geldclutch, he never noticed, being well into his fifth beaker of Martian Joy Juice.
‘For a neutron star, however, this is no longer true. Near the centre of mass the gravitational gradient – that is, the rate at which the field changes with distance – is so enormous that even across the width of a small body like a spaceship there can be a difference of a hundred thousand g’s. I need hardly tell you what that sort of field can do to any material object.
‘Flatbush must have been torn to pieces almost instantly, and the pieces themselves must have flowed like liquid during the few seconds they took to swing around the star. Then the fragments headed on out into space again.
‘Months later a radar sweep by the Salvage Corps located some of the debris. I’ve seen it – surrealistically shaped lumps of the toughest metals we possess twisted together like taffy. And there was only one item that could even be recognised – it must have come from some unfortunate engineer’s tool kit.’
The Commander’s voice dropped almost to inaudibility and he dashed away a manly tear.
‘I really hate to say this.’ He sighed. ‘But the only identifiable fragment of the pride of the United States Space Navy was – one star mangled spanner.’
Reunion
First published in Infinity #2, 1971
Collected in The Wind from the Sun
People of Earth, do not be afraid. We come in peace – and why not? For we are your cousins; we have been here before.
You will recognise us when we meet, a few hours from now. We are approaching the solar system almost as swiftly as this radio message. Already, your sun dominates the sky ahead of us. It is the sun our ancestors and yours shared ten million years ago. We are men, as you are; but you have forgotten your history, while we have remembered ours.
We colonised Earth, in the reign of the great reptiles, who were dying when we came and whom we could not save. Your world was a tropical planet then, and we felt that it would make a fair home for our people. We were wrong. Though we were masters of space, we knew so little about climate, about evolution, about genetics….
For millions of summers – there were no winters in those ancient days – the colony flourished. Isolated though it had to be, in a universe where the journey from one star to the next takes years, it kept in touch with its parent civilisation. Three or four times in every century, starships would call and bring news of the galaxy.
But two million years ago, Earth began to change. For ages it had been a tropical paradise; then the temperature fell, and the ice began to creep down from the poles. As the climate altered, so did the colonists. We realise now that it was a natural adaptation to the end of the long summer, but those who had made Earth their home for so many generations believed that they had been attacked by a strange and repulsive disease. A disease that did not kill, that did no physical harm – but merely disfigured.
Yet some were immune; the change spared them and their children. And so, within a few thousand years, the colony had split into two separate groups – almost two separate species – suspicious and jealous of each other.
The division brought envy, discord, and, ultimately, conflict. As the colony disintegrated and the climate steadily worsened, those who could do so withdrew from Earth. The rest sank into barbarism.
We could have kept in touch, but there is so much to do in a universe of a hundred trillion stars. Until a few years ago, we did not know that any of you had survived. Then we picked up your first radio signals, learned your simple languages, and discovered that you had made the long climb back from savagery. We come to greet you, our long-lost relatives – and to help you.
We have discovered much in the eons since we abandoned Earth. If you wish us to bring back the eternal summer that ruled before the Ice Ages, we can do so. Above all, we have a simple remedy for the offensive yet harmless genetic plague that afflicted so many of the colonists.
Perhaps it has run its course – but if not, we have good news for you. People of Earth, you can rejoin the society of the universe without shame, without embarrassment.
If any of you are still white, we can cure you.
Transit of Earth
First published in Playboy, January 1971
Collected in The Wind from the Sun
When this story was written the date 1984 did not seem impossible for a Mars landing – in fact that had already been proposed soon after the Apollo programme! There’ll be another transit in 2084 – but I hope humans will be on Mars long before then.
Testing, one, two, three, four, five …
Evans speaking. I will continue to record as long as possible. This is a two-hour capsule, but I doubt if I’ll fill it.
That photograph has haunted me all my life; now, too late, I know why. (But would it have made any difference if I had known? That’s one of those meaningless and unanswerable questions the mind keeps returning to endlessly, like the tongue exploring a broken tooth.)
I’ve not seen it for years, but I’ve only to close my eyes and I’m back in a landscape almost as hostile – and as beautiful – as this one. Fifty million miles sunward, and seventy-two years in the past, five men face the camera amid the Antarctic snows. Not even the bulky furs can hide the exhaustion and defeat that mark every line of their bodies; and their faces are already touched by Death.
There were five of them. There were five of us, and of course we also took a group photograph. But everything else was different. We were smiling – cheerful, confident. And our picture was on all the screens of Earth within ten minutes. It was months before their camera was found and brought back to civilisation.
And we die in comfort, with all modern conveniences – including many that Robert Falcon Scott could never have imagined, when he stood at the South Pole in 1912.
Two hours later. I’ll start giving exact times when it becomes important.
All the facts are in the log, and by now the whole world knows them. So I guess I’m doing this largely to settle my mind – to talk myself into facing the inevitable. The trouble is, I’m not sure what subjects to avoid, and which to tackle head on. Well, there’s only one way to find out.
The first item: in twenty-four hours, at the very most, all the oxygen will be gone. T
hat leaves me with the three classical choices. I can let the carbon dioxide build up until I become unconscious. I can step outside and crack the suit, leaving Mars to do the job in about two minutes. Or I can use one of the tablets in the med kit.
CO2 build-up. Everyone says that’s quite easy – just like going to sleep. I’ve no doubt that’s true; unfortunately, in my case it’s associated with nightmare number one….
I wish I’d never come across that damn book True Stories of World War Two, or whatever it was called. There was one chapter about a German submarine, found and salvaged after the war. The crew was still inside it – two men per bunk. And between each pair of skeletons, the single respirator set they’d been sharing….
Well, at least that won’t happen here. But I know, with a deadly certainty, that as soon as I find it hard to breathe, I’ll be back in that doomed U-boat.
So what about the quicker way? When you’re exposed to vacuum, you’re unconscious in ten or fifteen seconds, and people who’ve been through it say it’s not painful – just peculiar. But trying to breathe something that isn’t there brings me altogether too neatly to nightmare number two.
This time, it’s a personal experience. As a kid, I used to do a lot of skin diving, when my family went to the Caribbean for vacations. There was an old freighter that had sunk twenty years before, out on a reef, with its deck only a couple of yards below the surface. Most of the hatches were open, so it was easy to get inside, to look for souvenirs and hunt the big fish that like to shelter in such places.
Of course it was dangerous if you did it without scuba gear. So what boy could resist the challenge?
My favourite route involved diving into a hatch on the foredeck, swimming about fifty feet along a passageway dimly lit by portholes a few yards apart, then angling up a short flight of stairs and emerging through a door in the battered superstructure. The whole trip took less than a minute – an easy dive for anyone in good condition. There was even time to do some sight-seeing, or to play with a few fish along the route. And sometimes, for a change, I’d switch directions, going in the door and coming out again through the hatch.
Collected Stories Of Arthur C. Clarke Page 129