by Colin Kapp
High above them in the uncertain heavens a tiny fire-point denoted the position of the descending Tycho Brahe. Its visual distance belied the muted thunder of its thrusters. Even from the extreme altitude the sound carpeted the land with a pattern of sound which were reflected and amplified by the valley’s throat. With sweat on his brow, and a shielded microphone pressed at his throat, Van Noon was making the critical talkdown. At his side, Jacko, operating both rangefinder and telescope, recited a constant steam of information which served as an informative background to Fritz’s constant monologue.
The Labship, thrusters balancing its fall through the stratosphere, was weaving an erratic course into thicker air. Its point of destination was a mere approximation due to its curious deviations from the geocentric vertical. Everything now depended on the smooth continuance of the radio link with the Tycho Brahe’s pilot, and upon the pilot’s ready acceptance of Fritz’s instructions. In such a manoeuvre the pilot’s word was law. It was his decision to accept or reject advice affecting the safety of his ship, and his replies were routed via a laser link from the ship to the ground.
‘Make ready for touchdown. Central thruster to maximum…’ Van Noon’s voice continued precisely above the wave of sound as the mammoth ship loomed in the air above them. ‘Gently cut back… try for a very soft landing… don’t worry about the angle you’re making… Doing nicely now… only metres to go… Make sure the leg servos are off, and as soon as you feel the ground, cut thrusters.’
‘Are you mad? With the terrain sloping at this angle?’ The pilot’s voice came back with swift dissension.
Van Noon was firm. ‘Do as I say, or you’ve no chance whatever.’
‘Check! I can feel the ground. What about the gyro?’
‘Leave it running.’
‘Are you sure?’
‘I’m sure about nothing on Getawehi. But leave it running. Oh, and one thing more… for Pete’s sake don’t let your engineers dismantle anything. If they do, they’ll never get it re-assembled.’
A blinding hailstorm of dislodged ash soil settled in a broad area to reveal the Tycho Brahe safely planetbound but leaning at a decided angle to the vertical. Open mouthed, everyone waited for her to topple.
Those of Wooley’s team who were able to manoeuvre sleds ‘downhill’ came shooting across the valley, convinced they were on their way to a major catastrophe. Van Noon only smiled slightly to himself and directed Jacko to watch the stability of the Labship’s landing pads, which were buried deeply in the loose Getawehian soil.
As the uncertain gravity altered its angle and continued its slow rotary progress it became apparent that the towering mass of the ship was not going to topple. Jacko reported that the landing assemblies were firmly planted and showed no sign of wanting to tear out and wander, as had those of the first ferry on Getawehi. With an air of uncertainty the great craft moved in a broad arc as the angle at which the ship was leaning followed the migrating highest point of the horizon. Even so, it was nearly half an hour before the shipboard establishment cancelled the state of emergency and could be encouraged to open the hatches and leave the ship.
Characteristically, once the decision had been made, Colonel Nash was first out. He moved thirty paces from the ship, turned and looked dubiously at the huge bulk leaning above him. He winced and then set off downhill at a steady run until he was sure he had put more than a ship’s length between himself and the metal Nemesis. During the course of the run, what had been downhill became across-the-hill and finally began to curve upwards. He stopped then, shaking his head sadly, and walked the rest of the way to Fritz’s control point.
Van Noon wearily laid down the microphone and saluted. ‘Welcome to Getawehi, Colonel!’’
‘It’s an experience I could well have done without,’ said Nash. ‘I must congratulate you on safely conducting our touchdown, but it does raise a few interesting questions.’
‘Like what, sir?’
‘Like how the hell did you do it? Every other craft has either toppled or walked its way to destruction.’
‘Simple,’ said Fritz. ‘I played Getawehi at its own game. If Getawehi wants it that “up” is angled umpteen degrees from the geocentric vertical, then so be it. Let the ship come down out of vertical, and let it stay that way when it’s landed. The thing you mustn’t do is try to fight it. It’s axiomatic that Getawehi is going to have a last word.’
‘But won’t the Tycho Brahe walk?’
‘No, and for the same reason. The leg servos, which are responsive to the geocentric vertical, have been cut out. We’re not trying to use a stiff leg where a bent one is needed.’
‘I’ll take your word for it,’ said Nash heavily. His eyes were still nervously watching the trials of the leaning spaceship. Then he shrugged resignedly. ‘Very well, Fritz! You’ve got the Tycho Brahe down here, hyper-radio transmitters, computers, and all. You’ve demonstrated that the Ixion structure cannot be built— so now let’s hear your plans for an alternative.’
‘First,’ said Fritz, ‘I have to prove a theory. For that I need the computers and a lot of manpower. If I can prove what I suspect is true, I shall then need contact with Terra to verify that Getawehi itself can supply the information that Ixion was intended to collect.’
‘The entire ship’s facilities and the manpower’s yours. All I ask is that we can make a getaway from Getawehi in a reasonably short period of time. Which reminds me, you haven’t yet explained how you managed to acquire such a powerful radio transmitter.’
‘I left the details of that to Jacko Hine. But I don’t think he much likes talking about it either.’
Seven
It took three weeks. Teams ranged over a several hundred mile radius before Fritz could collect and collate the necessary information. For most of this time the shipboard computers on the Tycho Brahe worked continuously, sifting the data from the on-line transducers and from recorders which the sled teams kept bringing in. Piece by piece the pattern which Van Noon had intuitively deduced was verified and described in the mathematical detail which only a high-power computing complex has the ability to construct. From this Van Noon re-drew his simplified models more suited for communication between humans. When he was satisfied, he established a hyper-radio link with Terra. For three days more the ship’s computers chattered to and were interrogated by their counterparts back home, while Van Noon himself argued on a more prosaic level with the Ixion Project design team.
On the last day he gained the point he had been seeking, and called an immediate conference of all senior personnel concerned. When they were seated, he rose and passed the message transcript round the table.
Van noon, Tycho Brahe
We agree all points. The information supplied proves the Ixion entropy concept valid and viable. The project has now been drawn to a successful conclusion. This is a historic moment. Congratulations to all concerned
Ixion control.
After a few minutes Colonel Nash rose uncertainly to his feet.
‘Gentlemen… I’m sure we’re all glad to know that the Ixion concept is viable. And I’m sure we’re all delighted to share in the congratulations for the successful conclusion of the project—especially after it was so nearly a disaster. But I have one important question to ask. Fritz… what the hell is going on?’
Van Noon stood up, grinning broadly. ‘I must apologize, gentlemen, if the last phases of the operation seemed something of a mystery. The trouble was that I leaped to a conclusion about Getawehi which was so unorthodox that I doubt if you’d have given me a second hearing had I attempted to explain. Fortunately, events have proven me right. In case any of you haven’t already reasoned the position for yourselves, I shall now be happy to explain. Of course, the whole key lies in the peculiar nature of Getawehi’s gravity.’
‘You have an idea of what causes the variations?’ Brumas was sharply attentive.
‘Yes. I theorized that the effect was consistent with the presence of orbiting satellites of
very considerable mass. In point of fact, what we were experiencing was the result of several interacting gravitational attractions rather than the single one to which we are accustomed on Terra.’
‘Ingenious!’ said Brumas. ‘But not very convincing. To take the main point—Getawehi has no satellites.’
‘I’m afraid you’re wrong,’ said Van Noon. ‘We have orbital plottings of three major satellites and the reasonable suspicion that at least another twenty minor ones exist.’
‘Rubbish! I tell you there are no such things.’ Brumas was becoming annoyed. ‘Dammit, we’ve been observing the planet from space for over six months now.’
‘From space you wouldn’t see them. You see, Commander, they happen to be internal satellites—orbiting beneath the planetary surface.’
‘Nonsense?’ Brumas flared with anger. ‘If this is some sort of a joke… !’
Colonel Nash rose and calmed the sudden uproar. ‘Gentlemen, I think you now see why Lieutenant Van Noon didn’t attempt to discuss the matter before. Very few of you have been exposed, as I have, to Van Noon’s contempt for orthodoxy. At first sight it always hits below the belt. But somehow the damned idiot always makes it so plausible that I can assure you it’s futile to get into an argument with him.’ He turned back to Van Noon. ‘I assume, Fritz, that you do have some justification for this amazing statement?’
‘Certainly!’ Fritz was unruffled. ‘By the use of weight-loaded strain gauges distributed over a wide area, we have been able to plot the mass, size, and orbits of the three major satellites. The orbital information is precise and all orbits fall well within the mantle of Getawehi. The mass and size figures are enough to make your hair curl.’
‘Why so?’
‘Because the only material known in the universe which could possibly have that mass and density is material which has itself suffered gravitational collapse—degenerate star-matter. Matter so far collapsed on itself that its atoms are virtually in contact with each other.’
‘As would be material from completely exhausted dwarf-stars?’
‘Yes. Factually, these small satellite bodies constitute over two-thirds of Getawehi’s actual mass. Their orbital speed is low, and the planet is virtually an envelope which lollops around the variable centre of gravity of the satellite group. Getawehi’s surface gravity is a compromise between its own weak attraction and the higher, yet mobile, attraction of the hyper-dense orbiting nuclei.’
‘Are we to understand, then, that Getawehi is hollow?’ Nash was puzzled.
‘Far from it. Its internal structure is probably not too dissimilar from that of Terra, except that the crust and solid mantle of Getawehi must be many times thinner. Also the whole inner core must be in a molten state—probably molten nickel-iron. It’s within this core of liquid metal that the satellites orbit.’
‘If you say so.’ Nash settled back and chewed his moustache. ‘Very well, Fritz! I’ll accept that, because I’ve no doubt that you have it well documented. Now tell us what you used as a substitute for the Ixion assembly?’
‘In a moment,’ said Fritz. ‘First let me deal with the electrified desert, since it’s all part of the same story. There just had to be some natural mechanism available capable of producing substantial voltages at an almost limitless current. I approached the problem by considering what type of generator could produce this order of electrical output. The only reqasonable answer was a homopolar generator.’
‘A what?’
‘A homopolar generator—the simplest electrical generator ever devised. It consists essentially of a large conducting disc or rotor, spinning in a magnetic field. Once I had hit on the idea of satellites orbiting in a molten metal core, the answer was obvious. Gatewehi has a strong magnetic field, and nine-tenths of her volume is a rotating ball of conductive, liquid metal. Getawehi is a homopolar generator, and one of no mean proportions. The black rod-like terminals apparently project through the solid mantle and act as current pickoffs. I suspect that variations in output are somehow associated with satellite turbulence and to the fact that frequently the whole system gets its axis out of line with the planetary magnetic field.’
‘But you still haven’t built another Ixion,’ argued Nash.
‘I didn’t need to. As I thought, the Ixion structure was a massive but fairly simple device, intended to detect some of the oddities of entropy distribution in the continuum by measurement of fairly simple parameters. It was obvious that it was going to work because all the dimensionless numbers relating to entropy calculations are different on Getawehi—and even the dimensional numbers have adapted to follow suit.’
‘But the hardware?’
‘It wasn’t needed. The criterion of Ixion was not its complexity, but its size. When I offered Terra not a large turntable but a planet-sized ball of rotating metal complete with current pickoffs, they were overjoyed.
They had to re-calculate their parameters, but we were able to feed them in a few days of the type of data that the Ixion structure might have taken centuries to produce.’
‘Hmm!’ Nash was thoughtful. ‘As usual, Fritz, you seem to have all the answers. But I can see some of the technical boys have their toes curling up. I suggest we adjourn for a while to allow them to catch up on the figurework. As for you, Fritz, you’re coming with me.’
‘Where to, Colonel?’
‘To show me what the hell Getawehi uses as a high-power radio transmitter. I swear I’ve examined every square inch of this planet by telescope without detecting even so much as a banana plug.’
Van Noon shrugged. ‘I suppose you won’t be satisfied until you’ve seen it for yourself… and you may not believe it even then.’
As the sleds neared the range it was possible to see the light from the burning mountains even in broad daylight. Despite a favourable angle of slope, Colonel Nash halted his sled at a distance and took out his field glasses to study the phenomenon. Van Noon drew up alongside.
‘How does it work?’ asked Nash at last.
Fritz waved his hand. ‘As with the steppe, the whole ground-mass is electrified. The mountain itself is a great mineral outcrop which consists largely of conductive silicates and laminated strata of various metals including gallium and its compound arsenide.’
‘So?’
‘So the whole mountain is electrically alive, with random electrical potentials everywhere. In the high voltage periods the great mountain currents surge through the partially conducting, partially semiconducting layers, inducing all manner of curious effects. One of these effects is to cause some of the gallium arsenide layer to convert the current flow direct into light.’
‘Of course—electroluminescence!’
‘It doesn’t stop there,’ said Fritz. ‘None of the metalloid layers are particularly pure, and all of them contain numerous slip-faults. In these circumstances it is inevitable that you find a profusion of naturally formedp and n junctions which would drive a solid-state physicist psychotic. As the potentials vary you get huge transistor switching actions with thousands of amps being diverted up and down the mountainside like the great grand-daddy of all thyristors gone crazy. That’s why you get the glow running and shimmering through the mountain like that.’
‘Fantastic! If I hadn’t seen it myself I’d never have believed it.’
‘You haven’t seen anything yet,’ said Van Noon.
By the time they reached the foot of the mountain itself the glow had died as abruptly as on the occasion when Fritz and Jacko had first seen it. Now the fissured and laminated glassy blocks of the mountain lay apparently lifeless and inert, and only the instrumented probes which Fritz applied to the surface showed the drift and drain of the electrical currents still surging in the mountain.
‘Look to the end there,’ said Van Noon. ‘Where the mountain reaches down to the steppe there’s a silvery outcropping containing a series of thrust faults. That’s a typical formation distributed widely over the surface of Getawehi. Like the burning mountain, the lamellar l
ayers show marked transistor action. The outcrop is predominantly laminated silicon semiconductor layers. Subjected to the terrain currents, almost every similar outcrop is a radio transmitter at some state of the current flow.’
Nash stopped and wiped his brow. ‘I won’t buy that one, Fritz. I grant you that you have the current and you appear to have the semiconductor material. But even I know that you don’t get a radio transmitter by throwing random transistors into a box.’
‘No,’ said Fritz, ‘but there is a logical explanation. In these fractured semiconductor masses you have potentially every aspect of transmitter function: capacitance, resistance, inductance, switching, amplification, and even piezo-electric oscillation. And you have time.’
‘I don’t see what time has to do with it?’
’Evolution takes time, Colonel. Pass too much current through a transistor junction and you destroy it. Start with an infinity of potential transistor circuit paths and destroy and modify them slowly, and one day you’ll strike a circuit which will function—it will dissipate current rather than be destroyed by it. Continue the process for long enough and the only circuits which survive will be those capable of dissipating energy. Thus active circuits will become the rule rather than the exception—by a process analogous to natural selection on a biological level. The burning mountain survives by dissipating the electrical energy in the form of light. The small outcrops predominantly dissipate in the radio frequencies.’
‘I still find it hard to believe,’ said Nash.
‘When you consider the capabilities of natural selection processes, a radio transmitter is a far less unlikely product than is a human being,’ said Fritz quietly.
Nash looked at his hands reflectively, then nodded. ‘And you used one of these outcrops as a transmitter to contact the Tycho Brahe?’
‘We had to—er—modify it to suit our needs. But yes—that’s basically what we did do.’
‘I see,’ said Nash. ‘Your ingenuity does you credit, Fritz… but then I suppose that’s what we employ unorthodox engineers for.’
