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.