by Larry Niven
But Vassal thought so much faster than a human being.
“I need to know this,” she said. “You told me about the weapons Council is carrying. What about the antimatter?”
“I promised Treesa that you and she and Ali would talk about this together if it came up.”
Rachel’s Library access had always been restricted to certain topics, and Astronaut had limited choices. Treesa had relieved Vassal of some restrictions, tinkering with the rule base that defined its boundaries, allowing more natural conversations. Vassal didn’t refuse queries from Rachel. Until now.
“You mean you won’t tell me anything about antimatter?”
Vassal repeated itself. “I promised Treesa that you and she and Ali would talk about this together if you asked.”
Rachel laid a last tomato in the basket she held, then gathered the other basket up, preparing to run them to the kitchens. She frowned. When AIs thought they were hitting rules, they stopped. “I have asked. Set it up.”
Three days later, Rachel walked uphill after her children’s horticulture class, a cool wind in her face, blowing down the crater and toward Clarke Base. Vassal had arranged a meeting between Rachel, Treesa, and Ali on one of the low shoulders of the outside of the crater, on a large pile of rocks topped with one huge round rock a hundred yards above Clarke Base. Ali called it “Turtle Rock.” From the crater rim, from Council Aerie, it looked like the top of a sun-baked box turtle, and from Clarke Base the edge of a long flat rock, wedged under the round one, could have been a turtle’s beak in silhouette. Turtle Rock squatted a hundred yards from the switch-backed path between Clarke Base and Council Aerie.
Rachel perched on the turtle’s beak, watching a space-plane land at the new field just past the warehouses. Probably carrying more Earth Born and Council to Selene. Idly, she wondered how her plot was growing in Aldrin. A small crew remained there to tend the city.
She scanned the sky for Treesa and Ali, who were coming from Council Aerie. Clouds were tinged light pink and orange as Apollo set, yet Harlequin’s light still illuminated three winged shapes above her. She recognized Ali’s wings—decorated with jungle camouflage colors—and Treesa’s nearly transparent wings with bright orange and red fish swimming on them. Just like Treesa to make fish fly. The third set of wings was familiar, but it took a moment to make out Bruce, the limping old Earth Born who helped pull the tree off Beth during the fire.
Rachel scrambled off the beak into the center of the turtle’s back as the others landed.
Ali was fastest out of her wings. She bounded up near Rachel. “Treesa invited Bruce along.”
“Why?” This conversation should be between Rachel and her two Council mentors! Rachel watched Bruce stack his wings neatly and start methodically up the rock toward them. He still moved carefully, favoring the leg he had injured in the fire.
Treesa beat Bruce to the side of the other women, and said, “Antimatter concerns Earth Born too. I invited Bruce; he may be helpful explaining it to you.”
Rachel shrugged, and then said, “It increases our risk.”
Treesa nodded. “Yes, it does. But it’s time to combine as many people as possible—everyone that shares our views. You already know Bruce.”
“Yes. Hello, Bruce,” Rachel said. Astronaut was supposedly blocking this meeting from most recording. They were safe enough for the moment. “Bruce, why haven’t you gone into cold sleep?”
He said, “Rachel, you always have to consider what you’re teaching. We Earth Born, we’ve been using nano to keep ourselves alive and young. It’s against our principles. We do it because some of us have to follow long-range plans, really long. But somebody has to grow old and die.”
“You?”
Bruce smiled at her. “So the rest will know they can.”
Treesa grimaced. She asked, “Bruce, what do you know about antimatter?”
“I understand physics.” He was still watching Rachel. “Antimatter is what gave us the ability to run away from Earth. Before antimatter, we didn’t have any fuel powerful enough to push a ship the size of John Glenn past the influence of Earth’s sun. We had solar sails, we had deuterium-tritium fusion, and we could get around Sol system well enough if we were patient.”
“So without antimatter, we wouldn’t have gotten here,” Treesa prompted.
“That’s right. But antimatter is hard to make. We carried everything we needed with us to get to Ymir. But the scoop went screwy, so we didn’t have the interstellar hydrogen to use as working mass, so the only way to slow down was to use too much antimatter and our whole damn water supply—” He saw she was looking blank. “John Glenn is massive. We burned most of our reserves getting here, and damn lucky to get anywhere.”
Rachel wanted to hear about it from Ali and Treesa. To Ali she said, “Remember once, before I went to the ship the first time, I asked you about making antimatter on John Glenn, and you said it was too dangerous. Tell me again why you can’t make it there?”
Treesa laughed. “Antimatter is made when things too small to see hit other things too small to see moving very fast. It takes a really long tube—longer than John Glenn is tall. After antimatter is made, it can’t touch anything we touch.”
“It can’t touch what we touch?” Rachel repeated. “How do you use it?”
“Well, when antimatter touches matter, it all disappears into energy,” Treesa said. “That happens in the engines on John Glenn, and even on the bigger tugs and ships like Water Bearer, that crashed in the fire. It happens in safe places, controlled by magnetic fields, and the immense power of tiny bits of antimatter meeting matter—on the carrier we use water and antiwater—it makes a hot explosion, and we use the energy of that explosion to drive the ship. For daily power, we use very little antimatter, and trap energy in batteries to be released later at a reasonable rate. For example, little ships, Service Armor class ships, use batteries.”
“It’s more dangerous than I thought,” Rachel said, looking accusingly at Ali. “Remember when you said that it wasn’t a very big deal, you said that most accidents wouldn’t do much harm?”
“Well,” Ali said, with dignity, “most accidents won’t.”
“But how bad would a big one be?” Rachel asked. “What would happen if a big quake hit and a bunch of antimatter dropped onto Selene? Selene is matter.”
Ali’s voice was measured. “We’re careful, Rachel, accidents like that won’t happen.”
“But what if they did?”
Ali sat up straighter, speaking slowly as if picking through her words. “Rachel, we built Selene so we could build the collider here. In Sol system, we used one of Saturn’s moons, Janus Alpha. It wasn’t inhabited, so it was a great place for a collider.”
“Selene is inhabited,” Rachel shot back.
“Well, Janus Alpha became inhabited by the people needed to make the antimatter,” Ali countered.
“Was there ever an accident on Janus Alpha?” Rachel asked.
“No.”
“You didn’t answer me,” Rachel said. “What would happen if I dropped antimatter on Selene. Say—this much?” She picked up a rock just bigger than her fist.
“I think that would be bad,” Bruce said, his face deadpan, his eyes sparkling.
Rachel wanted to laugh, but dammit, this was serious.
Treesa sighed. “Rachel, if that much antimatter dropped in Clarke Base, Clarke Base would be gone. A tug like the one that Gabriel used to bring Refuge here went almost to the sun and back—using Daedalus to gain speed—with less than a glass full.”
“So it would destroy us.”
“That’s not the problem, it won’t happen.”
“So tell me why not.”
Treesa and Ali lapsed into a long explanation of how the collider was being built, and how the antimatter was captured and stored in magnetic vacuum bottles. Each held only a small amount. There was a special process to fill the stinger in John Glenn’s stern from the vacuum bottles. That alone would take a ve
ry long time. The explanation only made Rachel a little happier.
“Yet again, why can’t you build it somewhere else?”
Treesa sputtered, “That’s—that’s what we made Selene for.”
“There are other moons. Didn’t you make Selene to make the materials to make the industry?” She looked to Bruce for support. “Your children are here, Bruce! Don’t you care that Selene could—could explode?”
“Of course I care,” he said evenly. “But, Rachel, the whole reason for Selene is the collider. I want to see John Glenn leave. I came from Earth; I know why we have to go on. I’ll stay here, stay with my kids, I’ll die here, but John Glenn does need to join the rest of mankind.”
Rachel looked at each of them, feeling alone. No one was supporting her? Was she crazy? Not if she understood.
Ali said, “Think, Rachel. This has never been a secret from you. We wanted to meet to talk to you”—subtext—we wanted to talk in person and not through Vassal—“because we thought you might be afraid of this. But you shouldn’t be. Your worry should still be how the Children can build a viable society, and convince Council to build a viable society—so that you won’t be wiped out a generation after we leave. So that you can hold Selene together. We want you to have a chance on Selene.”
Rachel blinked, confused. How could they support her so well, agree with her on so much, and not see why this was so important? “Then don’t do something this dangerous on my home.”
Treesa just looked at her. “It has to be done.”
Ali followed. “It will be safe enough.”
Rachel stood up. “You said that you want Children to have a voice on Selene. That’s why you took so many risks, to help me teach the Moon Born things that other Council won’t. Well, I’m asking. Why can’t the collider be built on some other moon? There are plenty around.”
Ali shook her head. “Neither of us is High Council.”
“Does Gabriel support this? Really support it, not just go along?”
“He’s cold,” Ali said simply.
“The restrictions about talking about this, are they gone now?”
Treesa looked tired, but she smiled at the question. “Yes. I’ll tell Vassal to answer your questions.”
That night, Rachel lay still in bed, listening to her father’s gentle snores. He had encouraged her to question Council. She trusted them—at least she trusted Treesa and Ali—but they were risking her home. They were damned picky about which technology they allowed and which they didn’t, and no one seemed afraid of antimatter. But a fist-sized blob of antiwater would destroy Clarke Base. Why had Bruce laughed?.
The math was simple. Matter + antimatter = energy. Energy in ergs was mass in grams times the speed of light squared, a tremendous number, doubled because an equal mass of matter was disappearing too. The numbers were simple; the problem was in believing the results.
She imagined Selene’s soil spinning away from the core, trees and jungle and people flying away in a burst of explosive energy.
Council used antimatter regularly, safely.
But the numbers—
If she dropped a prize antiwatermelon—a watermelon sized glob of antimatter, ten kilograms—at Clarke Base, Clarke Base would be gone, true. Curse Bruce! Selene would be gone, dust and stones and superheated plasma scattered across the moon system and beyond. No wonder Bruce had hidden a laugh. If she built the antimatter at another moon. . . . She tried it with Eris, a chaotically tumbling moon far from Harlequin, smaller than Selene, but massive . . . and dropped the same ten-kilogram glob. The math gave her radiation and meteoroids from the explosion. It would probably kill every life form on Selene.
You couldn’t get John Glenn to Ymir for ten kilograms. It took twelve hundred.
She’d had access to the numbers all along, via Astronaut, via the Library. She just hadn’t known what to look for.
CHAPTER 56
MID-WINTER AT CLARKE BASE
THREE WEEKS LATER, Shane hadn’t reassigned Rachel. She’d taken to looking over her shoulder for him, and didn’t like the feeling one bit. Mid-Winter Week came and Rachel was dismayed to notice that the Children had only one day off for their own projects. The next three days Council worked them as a group, scrubbing buildings and streets in the base. That is, everyone except the crews working on the collider. Those had no time at all away from their usual duties.
Mid-Winter Night was different too. They weren’t allowed to gather in a single group. Separate areas had been set up for the young children, the Moon Born adults like Rachel and Beth, and for the Earth Born. It wasn’t that simple of course, there was movement back and forth as parents flowed from the children’s areas to the two adult areas, and mixed married couples flowed easily between. Council patrolled everywhere, watching.
The Moon Born adults gathered in a cleared area between four greenhouses. The lights were white and utilitarian, and far too bright. Still, some effort had been made. Consuelo had herded some of the other cooks into extra duty making thin fruit cookies with rare sugar imported from John Glenn, and the usual bananas and even plates of chocolate rested on long tables. Three uniformed Council watched from the corner, protecting a tiny box that played music.
Rachel, Beth, the twins, and Dylan and Kyle sat at a table as far from the Council corner as they could get. Kyle and the twins were on the same team on the parts factory, and Beth and Kyle flirted so incessantly Rachel was betting on a contract announcement any day. The twins, at barely sixteen, were five years younger than Kyle, but already nearly as tall and broad as Kyle. Working in the parts factory had bulked them out, and they ate from plates full to overflowing.
“So,” Jacob said, “do you think the Council over there are just making sure we get enough to eat?”
Dylan grimaced. “Sure. They’re making sure the chocolate gets handed out. But I bet all the wine goes to the Earth Born.”
Beth sat with her fingers intertwined in Kyle’s. “Let’s forget about fighting, just for tonight. Beside”—she looked at Jacob and Justin—“you two aren’t old enough for wine anyway. They won’t bring that out until you little ones get to bed.”
“Well,” Jacob teased, “look at the twenty-year-old lady lording over us all.”
“She didn’t mean it that way,” Kyle said.
“I know.” Jacob grinned. “Besides, we’ll have our own party later.”
“Shhhhh,” Rachel said. It had become a tradition for the young Moon Born to hold their own party, after the rest of the groups had been handed wine, after the Selene Born had figured out how to buy or steal or trade for some of their own. “Don’t even think about going out with the older boys. Just stay where you’re supposed to, and have a good time. We don’t eat this well all year.” She popped a chunk of dark chocolate into her mouth.
Justin glanced back at the Council. One of them, a black-haired woman who looked like an official version of Consuelo, only younger, was watching their table. “Don’t worry,” he told Rachel, “Andrew told us to behave. He thinks we’re being watched.”
“Good,” Rachel said, leaning into Dylan, enjoying the feel of his arm around her shoulder.
“That doesn’t mean we won’t find girls,” Jacob said.
“No one suggested that,” Rachel said dryly. She sighed. Certainly the lesser of two evils. “But be home before dawn.”
“You’re not our mom,” Jacob said.
Justin nudged him. “We’ll be home. Tomorrow’s still a day off, but we’ll save some energy to help you with dad.”
Rachel smiled. “Thanks, Justin. I appreciate it.”
She and Dylan and Beth and Kyle watched the two younger boys start to make the rounds, moving from one table of young girls to the next, laughing and eating. After the younger people, including the twins, had been cleared out, a Councilman Rachel knew, a man named Dean, with gray hair and ice-blue eyes, stood up and addressed them.
“This has been a busy year. We appreciate the work that has been done, and toni
ght we celebrate.” The other three Council handed out wine, one silvery tall bulb for each Moon Born. Rachel smiled and took hers, opening the stopper and smelling the rich fruity aroma.
Dylan held his bulb up toward the center of the table, and whispered, just loud enough for the table of four to hear, “To a slow year for Council.”
Kyle smiled and nodded, but Rachel simply drank her wine, which had a lightly sour taste she attributed to Dylan’s toast.
CHAPTER 57
JACOB
SELENE SHIVERED. RACHEL spread her feet to gain balance. Hot coffee splashed over her hand and spilled onto the floor. She nearly dropped the cup. “Dad?” she called. “You all right?”
A moment of silence. Then her dad’s voice, shaking a little. “Just old. Haven’t felt a quake that big for a couple of years.”
Rachel wiped up the coffee, then looked around the tiny kitchen. At least nothing was broken. She poured another cup and took it to her father.
He smiled at her, and reached up to grasp the cup in his good hand. It was shaking, so Rachel guided his other hand to the cup. “Sorry, girl,” he said. “I shake up easier these days.”
“We all do.” She bent down and kissed his forehead. “Will you be all right? I’ve got to go. Sarah will be along in a few minutes. She can help.”
“I’ll be fine.” Frank took a sip of the coffee and settled back onto the couch that had been his bed for the last two days. “Take care of yourself.”
“All right, Dad. But get better, okay?” For the last few days he had barely been able to get out of bed. He slept half the time, his mouth open, snoring. His skin looked like paper.
As soon as she got out the door, Rachel sent a query to Treesa and Ali. “What would happen if you were making antimatter when this quake happened?”
There was no immediate answer. In the week that had passed since the meeting on Turtle Rock, both Council had stopped answering her questions about the collider.
As she walked down the path toward her classroom, she smiled to see Beth, Jacob, and Kyle pulling a cart with a long glass tube on it. The tube was bound for Refuge; part of a system to pump additional air in and out of Refuge if the drowned asteroid were full of people. Beth waved to Rachel, who started to walk over to the group. Maybe Jacob could go check on their dad.