Dark as Day

by Charles Sheffield

  Bat inclined his head to the Ligon Industries’ gangling scientist, who stooped over the workbench like an impatient stork. “Dr. Suomi pointed out, in the politest possible terms, that although I have my own areas of expertise, I am in some fields a scientific idiot. No method known to science could cause such a fusion reaction on Jupiter. My idea would have required that Nadeen Selassie, in the closing weeks of the Great War, develop not merely a new weapon, but a whole new physics. That was not merely improbable, it was impossible.

  “Before I could relax, however, Bengt Suomi sent me the results of a later test, one which at first baffled both him and me. He is going to repeat that test now, for my benefit and yours, in a form where it is much easier to see what is happening. Dr. Suomi, if you would be so kind?”

  “Indeed. Observe closely.” Suomi stepped forward and held up what appeared to be an empty glass cylinder with a metal plug at its upper end. He turned the big cylinder, half a meter long and almost as wide, with a showman’s flourish that did not at all match his mournful appearance. His arm was long and skinny, and Milly found herself thinking, As you can see, I have nothing up my sleeves. She tried to suppress the image. This was a life-and-death matter, no cause for joking.

  “You will notice,” Suomi continued, “that the cylinder appears to be lacking in contents. That is, however, not the case. The cylinder contains two things: hydrogen, at low pressure. And, at the bottom of the cylinder, approximately a hundred small spherical nodules taken from the body of Sebastian Birch.”

  “What! Let me look.” Valnia Bloom strode forward and tried to grab the cylinder from Suomi’s hands.

  “Dr. Bloom, they are too small to see with the naked eye.”

  “I know that, better than you—I’ve been working with Sebastian Birch for months. What I want to know is, where the hell did you get those samples?”

  Bengt Suomi looked at Bat. Bat turned to Alex Ligon. Alex Ligon said—looking, Milly decided, about as guilty as a human being could look—“I’m not sure, but I think they came from a medical test lab in Earth orbit.”

  “Did they now? Well, I suppose that’s remotely possible.” Valnia Bloom handed the cylinder back to Bengt Suomi. “I’ll have a few words with Christa Matloff about this.”

  Alex Ligon did his best to fade into the background, as Suomi went on, “Here we have a perfectly stable situation. Hydrogen, and nodules composed of some inorganic materials, co-existing without undergoing any form of reaction.” He stepped over to the workbench. “Now I place the cylinder on the fixed stand, and allow the piston freedom to move.”

  The bottom of the cylinder fitted neatly into a silver ring. The metal insert at its upper end mated exactly with a round-ended arm that protruded down from a bulky silver ovoid.

  “I can control the movement of the piston up or down with this wheel, decreasing or increasing the pressure within the cylinder. The pressure itself is shown on the gauge. Note that the value holds steady, and we presently have much less than a kilogram per square centimeter. In fact, it is necessary to apply upward force to hold the piston in position. Now I propose to lower the piston. Keep your eyes on the pressure gauge.”

  Suomi moved to the wheel at the side of the instrument and began to turn it. The piston visibly, and slowly, descended. The reading on the pressure gauge, just as slowly, increased.

  Milly thought to herself, Well, big deal. Pressure inversely proportional to volume. It’s behaving just the way that a perfect gas is supposed to behave. I hurried all the way over here, sweaty and smelly, to watch a demonstration of Boyle’s Law?

  The descent of the piston continued. The pressure within the cylinder went up in exact reciprocal proportion. It had reached a few kilograms per square centimeter, and Milly was ready to conclude that Bengt Suomi and the Great Bat were both nuts, when an abrupt change occurred.

  The value shown on the pressure gauge dropped to zero. At the same time the piston moved swiftly downward until the free space at the bottom of cylinder had vanished completely.

  “A visible anomaly, a definite anomaly,” said Bengt Suomi. “The volume drops to a vanishingly small value, but so does the pressure. What has happened to our perfect gas, with its pressure inversely proportional to volume?”

  He paused. Milly decided that Suomi didn’t just sound like a showman, he was one. He was making a meal of this.

  She said, “It’s very obvious. There’s been a phase change in the hydrogen. Gas to liquid, or to solid. The pressure/volume relation doesn’t apply anymore. You have a tiny volume of material, and no pressure.”

  She knew she’d hit it right, because Suomi said glumly, “That is a correct conclusion. There has indeed been a phase transition. The contents of the cylinder have gone from the usual form of gaseous hydrogen to a far denser form. The phase change takes place through the whole body of the gas almost instantaneously, with the nodules apparently serving as a catalytic agent for the condensation. This is what our experiments revealed. But what was the significance of this? I could see no relationship to any ‘doomsday device,’ or a weapon of any kind. Nor could my staff. The subtle mind of Rustum Battachariya was needed to unravel the mystery.”

  He bowed to Bat, who said, “I formed a clear mental picture, but I didn’t know how to calculate consequences. Sebastian Birch had an unnatural obsession with the clouds of Jupiter and Saturn. I asked myself what would happen if nodules like those in Sebastian Birch’s body were released into the upper atmosphere of a gas-giant planet. At first, there would be no interaction. As we saw, the nodules have no effect on low pressure hydrogen. But the nodules themselves are dense. They would fall rapidly through the planetary outer layers, to regions where the pressure was higher. And now there would be immediate and drastic consequences. The phase change that we saw would take place and spread with great speed through the whole atmosphere. The new phase of hydrogen occupies far less volume. Jupiter would collapse, catastrophically, to become a denser sphere only a small fraction of its current size.

  “After that phase change we would have a smaller Jupiter. However, the planet’s mass would remain the same, therefore its gravitational influence would not change. Ganymede, Europa, and the other moons would continue in their present orbits, unaffected. So what would happen? Nothing? I tried to imagine myself within the dark mind of Nadeen Selassie, and I was somehow sure there would be consequences—terrible ones. What might they be? I could not say. At that point, I again needed expert assistance.”

  Bat raised his eyebrows at Bengt Suomi. Milly reached another conclusion. She would never have dreamed it of Bat, but somewhere deep inside the man was as big a ham as Bengt Suomi—and they were both loving it. They knew they had their audience hooked.

  Bengt Suomi’s next sentence confirmed it. He said, “Let us dip into the past. Sometimes old theories have their uses. During the nineteenth century, the age of the Sun was much in dispute. Biologists and geologists needed many tens of millions of years for natural processes to have the necessary effect. Physicists, on the other hand, could imagine nothing that would offer the Sun so long a lifetime. Finally, Kelvin and Helmholtz came up with a proposal. It was wrong, as it happened, but it made sense. They suggested that the Sun remained hot because it was gradually shrinking in size. During that slow collapse, gravitational potential energy was converted into heat energy. There would be enough energy to keep the Sun hot and shining for many millions of years. The same thing happens when a star suddenly collapses. A vast amount of energy is released, enough to blow the outer layers of the star far way into space.

  “Now consider our situation. If all the hydrogen on Jupiter underwent a sudden phase change to a denser form, the planet would shrink to a thousandth of its present size. There would be a gigantic release of gravitational potential energy. We would see Jupiter collapse, but at the same time flare bright enough to make the Sun appear dim. Actually, we would see only the first millisecond of that change, because Ganymede and all the other moons would instantly
become charred cinders. That was Nadeen Selassie’s ultimate weapon; a weapon not based on fission or fusion, but on the release of planetary gravitational energy. The collapse would not be stable—at those induced temperatures, the phase change would rapidly reverse. But it would come too late to save anything from here to the Oort Cloud.”

  Magrit Knudsen said, in tones of wonder, “She was insane. She wanted to kill everyone.”

  “Oh, yes.” Bat nodded with every evidence of satisfaction. “Her final vengeance. In all this, it is difficult to feel any compassion for Nadeen Selassie. Our sympathies should go to Sebastian Birch. It is clear that he enjoyed no freedom of action in what he did. He was compelled, by Nadeen Selassie’s modification of his brain and his conditioning, to seek death within the atmosphere of Jupiter or Saturn. However, it turned out that Nadeen Selassie was wrong. Somewhere in her calculations she made a fatal error. The death of Sebastian Birch, fortunately for us, did not result in the extinction of all life in the solar system. But Sebastian Birch himself—”

  Valnia Bloom said suddenly, “She wasn’t.” And, as the others stared at her, “Nadeen Selassie wasn’t wrong.”

  “But we are alive,” Bengt Suomi said. “She intended all of humanity to die. She made a mistake.”

  “No, she didn’t. You are alive because we were lucky.” Valnia Bloom walked forward and peered at the transparent cylinder. “Those nodules, plus a few more back at Christa Matloff’s facility in earth orbit, should be the only ones in existence. Every nodule inside Sebastian Birch’s body was broken down and removed from him during a sluicing operation. The final check, to make sure that sluicing was complete, ended just a couple of days ago. If he had managed to get his hands on a spacecraft before that, and flown it down to Jupiter …”

  “We would not be here to discuss his actions.” Bat gave a great and gusty sigh of satisfaction. “A fortunate outcome, and a lesson learned. Sluicing of the nodules from Sebastian Birch’s body: we were ignorant of that all-important fact. ‘Against ignorance, the gods themselves contend in vain.’ Just so.”

  He seemed well content. It was Magrit Knudsen who said urgently, “You can talk about how lucky you were later. Don’t you understand the danger? I’ll pass the word at once. Every remaining nodule, anywhere in the solar system, must be located and destroyed. If I hear you correctly, a single one of them, dropped into the atmosphere of any of the outer planets, would start an irreversible reaction that would kill us all. We’ll start here.” She moved forward and grabbed the cylinder from the bench, ignoring Bengt Suomi’s gesture of protest. “I’m taking charge of this. Dr. Bloom, I want you to call the Earth facility at once. Every nodule that they can find must be accounted for and placed in high-level quarantine until we have agreed upon a safe method for disposal. Who directed the sluicing operation?”

  “Harold Launius.”

  “I don’t know that name, but I want you to go and find him. Tell him that no matter what he’s doing, he is now on special assignment and will report directly to the Jovian cabinet. We need to know exactly what he did, and how he did it. He must talk to no one else.”

  “He’ll have it all on record. He’s the best.”

  Valnia Bloom hurried out. Magrit Knudsen advanced on Bat.

  “Rustum Battachariya, you are a genius and someday I’m going to kill you.” She moved so that she could address everyone in the room. “I’m going to make myself unpopular with all of you. I know you have other work that you’d like to be doing, but this takes precedence. Anything that you know, or think, or even suspect may be slightly relevant, we have to hear about. I’ll apologize in advance, but you are going to be pestered until you wish you’d stayed in bed and missed this meeting. If anyone else asks what’s going on, you don’t tell them. Refer them to me. Any questions?”

  Bat glowered. Alex Ligon said tentatively, “My predictive models …”

  “Will manage for a while without you. Kate Lonaker and Ole Pedersen can hold the fort. Even in your worst scenario, as I recall it, humanity had a run of at least another half century. With Nadeen Selassie’s doomsday weapon in the picture, we almost went yesterday, and we could all go tomorrow. In any case, I’m not suggesting that we abandon other work—only that this must occupy the highest priority. Anyone else?”

  Milly was tempted to ask about the SETI effort, but she kept her mouth shut. She needed to talk again to Jack Beston. She wasn’t sure that she was ready or willing to resume their curious love-hate relationship. Yesterday the SETI signal and Jack had been the most important things in her universe, but what Bat and Bengt Suomi had said was finally sinking in. Yesterday, that same yesterday when the SETI signal mattered so much, she had almost died and never known it. The whole of life was suddenly a fragile possession, a delicate mystery that could vanish as randomly and inexplicably as it had appeared.

  Milly had said nothing, but Magrit Knudsen caught something from her expression. The older woman smiled at her.

  “There are days like this, my dear. You just have to hope that you’ll live to see a lot of them.” Magrit Knudsen turned again to Bat. “One more thing. I know how much you love to collect lost weapons from the Great War. I sympathize with that, and normally I approve of it. Now, I can imagine you saying to yourself, if I could obtain a few nodules that Nadeen Selassie implanted in Sebastian Birch—or even just one—that would be the finest war relic anyone could ever hope to own. And I would enclose them and insulate them and guard them so well in the depths of the Bat Cave, the nodules would never be dangerous to anyone. I couldn’t ever mention to anyone that I had them, but they would still be mine. Well, Bat, I have just one thing to say about that line of thinking. Don’t go there. Even if your devious mind sees a way to get your hands on more nodules, don’t do it.”

  “Very well.”

  “Is that a real yes? A personal promise, from you to me?”

  “I suppose.”

  “You suppose?”

  Bat was half a meter taller than Magrit and at least four times her mass. She stood, hands on hips, staring up at him in silence as he frowned, pursed his lips, puffed out his cheeks, and gave every appearance of a man in supreme torment.

  Finally he reached a hand into the pocket of his rumpled shirt and fumbled around. His hand emerged holding a great mass of detritus. Milly saw papers, an interface coupler, three keys and a tiny electronic lens, all glued together by what appeared to be lumps of hard candy. Bat reached into the middle of the mess with his other hand and delicately removed a capped metal tube a couple of centimeters across. He handed it over.

  As he did so he sighed like an expiring whale and said, “There is more than one way to kill a man, Magrit Knudsen. Take this; and with it, you have my solemn promise.”

  35

  CLOSURE, AND OPENING

  Bat floated in the bath, eyes closed and only his face and an island of rounded belly showing above the surface. He had not bothered to remove his clothes. Either the protozoan cleansers would be smart enough to recognize and ignore them, or they would eat them away along with every trace of grime upon his body.

  He murmured, “Peace at last. Or at least the temporary illusion of peace, which is all we can hope for.”

  He spoke to the ceiling, where Mord frowned down at him. Clean clothes hung draped over rails at the side of the bath. The bathroom, on the lowest occupied level, was otherwise devoid of fixtures. It did not offer the true sanctuary of the Bat Cave, but it was the best that Ganymede had to offer. Until Bat’s departure request for Pandora was approved by Magrit Knudsen, it must serve.

  “Temporary,” Bat went on, “because of course all the difficult questions remain. Yesterday’s urgencies swept them out of sight, but they will soon return. Alex Ligon lacks a strong personality, but he possesses intelligence and a persistent temperament. He will continue to explore the erratic behavior of his predictive models. He will quickly come to realize that the Seine itself is the source of variability of his results.

  �
�And then there is the failure of the Seine. It is self-monitoring and self-correcting. How could it cease to operate, totally and System-wide, for a full seven minutes? There is no suggestion that the Seine was somehow turned off during that period. Given that its speed and parallel processing capacity exceeds human comprehension, what task could have engaged the Seine’s attention during that interval of introspection? Also, what can explain the time at which that introspective period occurred?”

  He lay silent, until at last Mord said quietly, “I suppose you have answers for all those questions.”

  “I have theories, not certainties.” Bat opened his eyes. “As you know, one of my core beliefs is that there is no such thing as certainty. There are just different degrees of uncertainty. However, I am willing to offer speculations.”

  “That might be interesting.” Mord was curiously subdued, and his voice lacked its normal sarcastic bite.

  “Then I will reveal to you the sequence of my thought processes, fragmented and disconnected as they may seem.” Bat studied Mord’s image, frowned, and went on. “Oddities of all kinds interest me. You know that, and you have contributed much to my four-sigma list. Everything concerning Nadeen Selassie belonged on that list, and led us—belatedly, and thanks to Valnia Bloom irrelevantly—to Sebastian Birch.

  “Nadeen Selassie and her weapon became my main focus. I was beguiled by what we may term the fallacy of the single issue. I sought one explanation that could explain every anomaly—this, for a system as complex as the whole of human affairs and solar system operations. However, even in my blindness I noted other peculiarities which could have nothing to do with Nadeen Selassie and her Great War legacy. A surprising number of them revolved around the subject of aliens. Naturally, since the discovery of the Wu-Beston anomaly there has been talk everywhere of intelligent aliens; however, many of the rumors and mutterings and statements without any assigned source preceded the Wu-Beston discovery.