The Unorthodox Engineers

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 layers 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.’