by Colin Kapp
‘In this case,’ said Fritz, ‘I can’t help feeling that Jacko surpassed himself. He can claim to be the first man—and I suspect also the last—ever to add an audio modulator to a solid state transmitter… with a pickaxe!’
The Black Hole of Negrav
‘The basic philosophy behind the Unorthodox Engineers is simple,’ said Fritz Van Noon. ‘As our penetration of deep space continues, so communications and supply lines grow longer, finally impossibly long.
And the transport costs of even simple items become disproportionately high.
‘For instance, the price-penalties of space-freight are such that a simple spanner required on Aldebaran-seven costs sixteen times its weight of platinum on Terra. Assuming you can afford it, delivery time by hyper-ship can be anything up to three years.’
He waited until the buzz of conversation in the audience had died again. Then he continued. At his side, he was aware of Colonel Belling’s dark scowl of disapproval, but decided to ignore it.
‘If we’re to take advantage of the new space-territories the hyper-ships are opening up to us, if we’re to build out on the Rim something men can use as the foundations of a colony, we need engineering—and we need plenty of it.
‘So who should we send? Mechanics who can’t obtain any steel? Engineers whose nearest machine shop is fifty light years away? Or should we send the men who can make a plough out of a stick, a stone, and a length of creeper? The answer’s obvious. You can send a few tools, but the thing that counts most at the edge of the galaxy is man’s own unparalleled ingenuity—the ability to use anything available to your own peculiar advantage.
‘And that, Gentlemen, is the function of unorthodox engineering. It’s the habit of breaking with the traditional disciplines and learning how to construct the nucleus of a functional civilization out of bits of string and matchsticks, if necessary. To hell with what it says in the book. It may not even look like engineering—but if it works, it’s justified.’
Shortly the chairman brought the assembly back to order.
‘Well, now we’ve heard both sides of the argument—orthodoxy versus unorthodoxy in space engineering. I’m sure we’ve all been greatly enlightened, not to mention amused by Lieutenant Van Noon’s account of railways built over small volcanoes, and the use of harps as electrical power generators. While Van Noon’s approach may not seem as elegant as some of the precise and mathematical approaches we’ve heard his afternoon, it’s brought some very practical solutions to some very intractable problems. I therefore suggest we conclude this session with an opportunity for questions from the floor. Of particular interest would be a problem which orthodoxy has failed to solve.’
At his side on the speakers’ platform Van Noon felt Colonel Belling stiffen with anticipation, and knew that his worst fears were about to be confirmed. Belling’s consummate hatred of unorthodoxy was almost a legend, and a public showdown before such an influential audience was too good a chance for the Colonel to have missed.
The next question would be a loaded impossibility. Regardless of who delivered it, Belling would have had a hand in the draft.
A young officer in the uniform of the Space Territories Administration rose to his feet. He was obviously one of the new breed of academic officers not long from space college. He began with his own introduction.
‘Captain-Administrator Wilson, Rim Territories Survey. I’ve been fascinated by Van Noon’s treatise on the uses of unorthodoxy. It so happens that out on the Rim we have a good example of one of these intractable problems. We’ve known for some time that the star Springer 218G has a complex binary-planet system. But closer inspection revealed that the two bodies were of disparate size and we couldn’t understand how this orbit could be stable. That’s because the smaller one is really just a large asteroid we’ve called Negrav.’
Van Noon stole a sly look at Colonel Belling, whose expression of smug innocence confirmed his worst suspicions. This problem had been hand-picked by a master.
‘Perhaps I should explain,’ continued Wilson, ‘that the companion planet in the binary, it’s been named Leda, is a body of considerable interest to us because of its mineral resources. However, because of the rather odd complications of this system, we want to put an observation platform on the asteroid to let us study the situation before we commit expensive resources to the planet.’
Fritz Van Noon listened to this with a patient frown. So far nothing unusual had emerged. Therefore, whatever the problem was, it had to be a honey.
Wilson was deliberately avoiding looking at Belling. ‘I said the asteroid was called Negrav. The reason for the name is that the centrifugal force of its rotation at the equator exceeds the gravitational attraction of its mass. Thus except at the poles it has a negative gravity averaging about point seven Terrestrial. Unfortunately, because of its spin alignment, it’s a point on the equator we need for a base.’
‘If I understand you rightly,’ said Van Noon, ‘yours is a simple problem of securing buildings on to a surface which exhibits an effective negative gravity. This is slightly more difficult than free-fall work, but not much. Any good adhesive can get you started, and once you’ve obtained a reasonable foothold, you can anchor into the surface by any of a great number of standard methods?’
Wilson took the point sedately, but caught Colonel Belling’s eye and was hard-put to restrain the amusement which welled suddenly inside him.
‘It’s not quite as easy as that,’ he said, striving to retain his academic pose. ‘I said that Leda was one of an odd binary pair. It’s always been a puzzle how this could be stable—but now we know for sure that Negrav is not large enough to substantially affect the gravitational balance. Rather, it functions as a satellite to the real companion of Leda—which is a small black hole.’
‘A what?’ said Van Noon, sitting down weakly.
‘A black hole,’ said Wilson happily, under the approving eyes of his triumphant mentor. ‘The second component of the binary is a small black hole of roughly Terran mass, which has an event horizon of about one centimetre.’
‘And Negrav is in orbit about this?’
‘A very close elliptical orbit.’
‘How close?’ asked Fritz suspiciously.
‘It actually shaves the surface on its closest approach. Our problem on Negrav isn’t getting an observatory to adhere, it’s how to stop it being eaten by the black hole in grazing orbit—no pun intended. Orthodoxy doesn’t have any good answers. I’d be interested in hearing the unorthodox approach.’
Colonel Belling was still laughing the next morning. When Van Noon received a summons to report to his superior’s office at the Engineering Reserve he sensed it was only so that salt could be rubbed into an already smarting wound. It made a change, however, to find his commanding officer in a congenial mood so early in the morning. This was a situation Van Noon had plans to rectify.
‘Ah, Fritz! Sit down! I’ve to congratulate you. Your reputation for unorthodoxy is unimpaired. Nobody ever gave such an unorthodox reply to a question at a Space Engineering Symposium. I was particularly intrigued by what you told him to do with his black hole.’
‘It was deliberate provocation,’ said Van Noon. ‘A put-up job designed to discredit unorthodox engineering.’
‘Which it did beautifully,’ said Belling happily. ‘I always said I’d show you crackpots up for what you are.’
‘Then you haven’t heard yet?’ asked Fritz carefully.
‘Heard what?’ Belling’s suspicion was palpable.
‘General Nash was in the assembly representing Space Engineering Command.’
‘Of course. What of it?’
‘Well, the Unorthodox Engineers have pulled him out of several holes in the past. I think he saw the chance to return the favour.’
‘What chance?’
‘That building an observatory on Negrav wasn’t entirely a leg-pull. With respects, Colonel, you were so busy looking at the absurdity of it, that you overlooked the possibil
ity there might be a genuine need. It so happens there is a need. The Negrav-Leda complex promises to provide easily-won mineral resources for a large sector of the Rim, avoiding the long hauls from Terra.’
‘Go on!’ said Belling grimly.
‘Well, General Nash got together with the Director of the Space Territories Administration and offered to build the Negrav observatory for him. The Director was delighted, and an inter-Service contract was drawn up on the spot.’
‘And?’ asked Belling. He had the look of a man who knew what the answer must be, but hoped against hope that the truth could not be as bad as he imagined.
‘The contract makes this Engineering Reserve responsible for building the observatory,’ said Fritz, with an evil smile. ‘That means it’ll be your pigeon.’
‘I’ll never forgive you for this, Fritz.’
‘But I did nothing. It was you who had the matter raised.’
‘I still shan’t forgive you. It has all the hallmarks of your devious organization.’
‘And it raises a good question, Colonel. Who’re you going to send to Negrav? An orthodox engineering team —or a bunch of unorthodox crackpots?’
‘I still think it was a heck of a tough way of proving your point,’ said Sergeant Jacko Hine.
Van Noon scowled at his second in command. ‘Not even Colonel Belling believes me, but I had nothing to do with us being sent to Negrav. The construction orders came down from General Nash, and Belling had to recant on his orthodox approach because there wasn’t an orthodox way to do it.’
‘My understanding is that everybody else refused point-blank to go! I suppose it never occurred to you that there might not be an unorthodox way to do it, either?’
‘The thought did strike me, but I dismissed it as unlikely. Just how the heck we’re going to do it, I don’t have a clue at the moment. But at least it puts us marginally up on Belling’s approach.’
‘How do you figure that?’ asked Jacko dubiously.
‘Belling’s certain it can’t be done. I’m certain that it can. So all we have to figure out is how. That simplifies the problem no end.’
‘Ri-i-ight,’ said Jacko Hine slowly. ‘You’d better clue me up on black holes. If we’re to tangle with one, I’d like to know something of the enemy.’
‘The classical theory’s that of the collapse of a burned-out star. Once a star’s used up its nuclear fuel the radiation pressures holding it up fall right away. It begins to contract under its own gravity. The size of the star controls how far the collapse can go—the larger the star, the smaller it will become. If the start is large enough then nothing can prevent it continuing indefinitely. The whole thing collapses down to an infinitely small point called a singularity. Around the singularity is a region of space where the gravitational field is so strong that not even light can escape from it—this is what’s known as the “event horizon”.’
‘Since nothing that happens beyond that can ever be seen.’
‘Sure. Light—or anything else for that matter—can be drawn into a black hole by the intense gravity, but nothing, nothing at all, can ever get out again. It’s a one-way hole in space.’
‘What happens to the things it swallows?’ asked Jacko uneasily.
Ripped apart to atoms, and then those are ripped apart until all that’s left is randomised radiation. As to what lies on the far side—there are plenty of theories, but nobody actually knows.’
‘So how big is it?’
‘We can never know the radius of the singularity, but the size of the event horizon is determined by the mass of the black hole. Sol is too small to make a black hole, but if it could, the event horizon would be about three kilometres.’
‘But Wilson was speaking of one about a centimetre in size.’
‘There’s another possible way by which black holes could have been formed. In the big bang which kicked off the expansion of the universe. Theory has it that baby black holes of a mass around ten to the minus five grammes and ten to the minus thirty-three centimetres in diameter could have been formed then and would have been wandering space ever since, consuming whatever mass they chanced to find in their travels. It’s entirely possible for one of these mini black holes to be able to eat an entire planet and still not finish up much larger than a marble. It’s likely that’s what we’re dealing with at Negrav.’
‘It gives me a very curious feeling,’ said Jacko, to think of a little black hole which could eat a planet. The more I hear of this expedition, the less I begin to like it. As I said just now, I think you’ve chosen a heck of a tough way to prove your point.’
The great hyper-ship of the STA had carried them out to Chronos, on the Rim. From there another Navy vessel had taken them on to the STA base on New Australia. Here, a smaller vessel took them on the three week sub-light trip to Springer 218G, with its curious binary satellites and the asteroid Negrav. Two days from arrival, Van Noon called a conference of his five-man team.
‘Now you’ve all read the preliminary STA survey report on Negrav. When we get within telescope range, we’ll be able to supplement what we know with our own observations. I hope to be able to discover a few items which the STA observers haven’t mentioned because they weren’t looking specifically for them. It’s highly unlikely that Negrav is totally composed of nickel-iron alloy, or that its entire surface is as smooth and unbroken as the STA report suggests. Initially we’ll need to establish a foothold, and this’ll have to be well below the orbital path of the black hole, so what we want particularly is a deep fissure or crack which we can hook into and work safely below the black hole’s grazing orbit.’
‘Check!’ said Jim Fanning, the UE geologist. ‘But if the STA photographs are to be believed, you’d stand more chance of hatching ball-bearings than you do of finding fissures in the surface of Negrav.’
‘I’m aware of that,’ said Fritz. ‘The theory’s that Negrav was once a full-sized planet, and all we see now is a remnant of the core. The rest of it’s been eaten by that darned black hole. But I’m hoping at least for a blowhole or some form of depression. The frequency with which the black hole sweeps the surface gives us less than thirty-six hours between touching the surface and getting safely tucked down underground out of its way.’
‘If I judge you right,’ said Jacko, ‘you’re thinking of building the observatory beneath the surface?’
‘We obviously can’t build on the surface, because anything there gets eaten by the black hole. Besides which, it makes sense in other ways. Below the surface you don’t have to bring in construction materials. You simply carve out the shape of cavity you want. Also you can make use of the negative gravity, because the centrifugal force’ll drift you towards the roof of the cavity, thus producing a semblance of positive gravity. Once the observers get used to making their observations by peering down through windows below their feet, it should be a fairly effective working situation.’
‘All of which sounds very nice,’ said Fanning. ‘But I foresee a couple of practical snags. Like how do we get in deep enough quick enough to avoid being eaten by the black hole? And having got into the surface, how do we carve an observatory-sized cavity in what promises to be a very strong nickel-iron alloy?’
‘I admit it may be tough,’ said Van Noon.
‘Tough!’ Fanning was aghast. ‘Blasting won’t do much more than deform the surface, and oxy-acetylene cutting would take a lifetime—assuming you could get the supplies. So you’re largely back to processes like laser drills and the occasional hand file. At a rough guess, Colonel Belling was damned right when he said it couldn’t be done.’
‘I’ve told you all before,’ said Van Noon sternly. ‘Physical limitations aren’t absolutes. They’re a state of mind. They said iron ships wouldn’t float. They reached that conclusion because they hadn’t taken all the facts into account. From this distance I can’t see the answer to the Negrav problem either. But I’m sure as hell there is one: All we have to do is find it.’
Once the
y were orbit around Negrav subsequent observations did nothing to support Van Noon’s optimism. Negrav was a ball of solid nickel iron, and its surface was flawless and honed to a micro-finish which would have done credit to a precision ball-bearing. Because of its small size, the black hole remained invisible. Its relentless orbit around Negrav—or rather the orbit of the asteroid around it, which came to the same thing relatively speaking—had for some millions of years ceased to take more than microns of further material from the surface.
Now the black hole’s path hovered millimetres above the surface of Negrav and pursued a progressive rotation which effectively swept the entire sphere over a period of thirty-six hours. The position of the black hole was known with mathematical certainty at any time, but libration and other effects of the binary on the orbit of Negrav introduced an uncertainty factor. The black hole’s progress across the surface had to be described in terms of statistical paths rather than positional lines. In practice this meant that thirty-six hours was the longest period any point on the surface of Negrav could be guaranteed safe from the marauding black hole.
‘Which isn’t long enough,’ said Jacko Hine. ‘Working under space conditions and negative gravity, we wouldn’t have time to cut far enough into the surface to be any significant use. We’ve not only got to get into the hole, but around some considerable corner to prevent being drawn out by the black hole’s gravity.’
‘How far d’you estimate we could penetrate in thirty-six hours?’ asked Van Noon.
‘Judging by spectro-analysis of the surface material, we’d be hard-put to remove more than a cubic metre with the tools available. And once we get deeper, the work would slow considerably because we could only keep one man at the face.’
‘That’s not good enough,’ said Van Noon. ‘I’m going down to Negrav myself to study the problem from the surface.’
‘If it’s not a rude question, how do you intend to hold to the unbroken surface against negative gravity? Chewing gum?’