by Mark Alpert
Stop! What are you doing? Who—
Please be calm, Dorothy. Soon you will be reborn. Isn’t that what you wanted?
The red mud melted the skin off her back. She felt the hot, thick slurry seep into her chest and stomach. It dissolved her hair and leaked into her skull and drowned her thoughts. The voices inside her head grew faint.
You’re not him! You’re Satan! You’re … you’re …
I am the Word made flesh. I am the Light of the World.
FIFTEEN
Scientists are strange creatures, Sarah thought. They love to criticize and nitpick and tear apart each other’s work, but if you’re looking for someone to help you out at a moment’s notice, your best bet is to call one of your old friends from graduate school.
She sat in an office in Columbia University’s Science and Engineering Library at the corner of Broadway and West 120th Street. The office belonged to Phil Clark, a chemist who specialized in developing new polymers and other advanced materials. But that hadn’t always been his specialty. When he and Sarah had been grad students at Cornell he’d been just as obsessed with meteorites as she was. And when NASA had hired Sarah to study Martian meteorites, she’d asked Phil to help her analyze the rock that appeared to hold fossils of ancient bacteria. Phil had scrutinized the microscopic structures inside the meteorite and found that their iron-bearing minerals were remarkably pure, just as you’d expect them to be if they’d been synthesized by microbes. He’d reported this finding without any excitement. Nothing surprised Phil, not even evidence of extraterrestrial life. He was one of the most levelheaded men Sarah knew.
So now she was startled by the emotion on his face as he stared into the eyepiece of the scanning microscope on his desk. He was reexamining, for maybe the fortieth time, the sample she’d brought to his office yesterday, the half gram of metallic shavings she’d scraped off the blade of Gino Torelli’s ax. Normally, Phil was calm and methodical, but now his cheeks were flushed and his mouth hung open. He ran his hands through his thinning hair and flakes of dandruff sprinkled the back of his polo shirt. After a couple of minutes he lifted his head from the microscope and stared at a pile of printouts on his desk. The papers showed the results of all the tests Phil had performed on the sample over the past twenty-four hours: the mass spectrometry, the X-ray diffraction study, the dielectric analysis. He shook his head as he pored over the columns of numbers. He was a tall, gangly man, and his head swayed like a scarecrow’s.
He turned to Sarah. “You need to call a lawyer.” He pointed at the telephone on his desk. “But I’m not sure if you should call a criminal lawyer or a patent lawyer.”
Sarah’s stomach clenched. “Why? What did I do wrong?”
He frowned. “Where did you get this sample?”
She hadn’t told Phil about the gleaming cable she’d seen in the manhole. She was worried about the confidentiality agreement she’d signed. The Air Force could send her to prison if she said too much. “I told you, this is a sensitive thing. A national security thing. I can’t answer a lot of questions.”
“Did you steal it? From a government laboratory?”
“No, of course not!”
“I’m sorry, Sarah, but I’m having trouble believing you.” Phil folded his arms across his chest. “If you didn’t steal the sample, then you must’ve created this new material yourself. I’d be very happy for you if this were true, because the discovery would earn you many millions of dollars, assuming you hired a good patent lawyer. But I know you couldn’t have created it. You don’t have the expertise or the resources to do this kind of work.”
“I didn’t create it or steal it. I found it.”
“Then you need to tell me where you found it. Otherwise I can’t draw any useful conclusions from the test results.”
Sarah was exasperated. She didn’t know what to do. She’d given the sample to Phil rather than to General Hanson because she’d wanted to stay in control of the investigation. If the Air Force took over, they’d probably hide the results in some top-secret document and the truth would never come out. But doing it on her own was risky, not only to herself but to anyone who helped her. She didn’t want to tell Phil anything that would get him in trouble.
“Let’s just talk hypothetically. What if I said I got the sample from a space probe that crash-landed near here?”
Phil looked askance. “I’d say you were hallucinating. I haven’t heard of any spacecraft crashing into New York City lately.”
“What if it was just a piece of debris from a probe that mostly disintegrated in the atmosphere?”
“That doesn’t sound quite as insane, but I still don’t believe it.”
“Why not?”
He picked up the pile of printouts. “The material in your sample isn’t one of the alloys or composites used in spacecraft. It’s unlike anything I’ve ever seen. Most of it is an iron alloy, but it has a completely different mix of elements than the standard varieties of steel. And its crystalline structure? The way the atoms of iron and carbon and silicon stack together?” He flipped through the printouts until he found a full-page diagram, a rough schematic based on the X-ray diffraction results. “Come here and take a look at this. It’s ingenious.”
Sarah rose from her chair to look at the diagram. It showed an incredibly complex lattice of atoms, a structure that looked like a monstrous jungle gym. At its center was a tight packing of iron, carbon, and chromium atoms, a solid core that seemed to be optimized for conducting electricity. Surrounding the core were layers of semiconducting silicon, the same crystalline stuff that was at the heart of every computer chip. But the most fascinating features were at the edges. The lattice was lined with dangling strands of atoms. They extended from structures that looked like rotors and pivots. The tips of the strands were bent into minuscule hooks and cleavers.
Now she saw what had surprised Phil so much. Those strands and rotors and pivots were nanodevices. They were microscopic machines, smaller than a millionth of a millimeter, so tiny they could manipulate individual molecules and assemble them into new structures. Chemists and physicists and engineers had been working on nanotechnology for the past two decades, but most of the devices they wanted to build were still in the dream stage, and even their most outlandish dreams weren’t as sophisticated as the microscopic structures in this sample. Sarah was looking at a molecular marvel, and judging from the design of the strands, she could guess what they were supposed to do.
She let out a whistle. “Okay, this makes sense, believe it or not. These strands over here? The ones that look like fishhooks?” She pointed at the diagram. “They could bind to other molecules, right? To molecules of hematite or silicon dioxide or any of the carbonates in sedimentary minerals?”
Phil squinted at the page. After several seconds he nodded. “Yes, I suppose that’s possible. The lattice can capture the smaller molecules if they’re close enough and have the right polarity.”
“And these other strands, the ones connected to the pivots? They could pull the captured molecules apart, couldn’t they? And then the lattice could absorb all the iron and carbon atoms that get broken off.” Sarah tapped the page. “It can act as a drill, see? As it digs into the ground it would dissolve all the minerals in its way. And at the same time it would suck up the atomic pieces of the minerals and use them to enlarge the drill. To make it longer, so it could dig even deeper.”
Phil nodded again and stared at the diagram for a few more seconds. Then he raised his head and gave her a suspicious look. “You guessed its function a little too easily. I get the feeling you’ve already seen this drill in action.”
His face was close to hers, just a few inches away, which made Sarah uncomfortable. Twenty-two years ago, when they were both at Cornell, Phil had fallen in love with her. He’d spent months working up the nerve to ask her out, but by the time they actually went on a date—at a loud Mexican restaurant in Ithaca—Sarah already had her eye on Tom Gilbert, the charming, handsome postdoctoral s
tudent who was helping to design a microbe detector for NASA’s Mars probes. The next day she apologized to Phil and told him she was more interested in someone else. Phil took it stoically and never mentioned it again. Even after Tom betrayed her during the meteorite fiasco and she broke off their engagement, Phil kept his distance.
Now, in retrospect, Sarah regretted her choice, although she still felt no attraction for Phil. He was too bland for her, too serious. But, she had to admit, he’d been a loyal friend. Unlike Tom and everyone else at NASA, Phil hadn’t betrayed her. He’d continued to support her claim that microbes had once thrived on Mars. So wasn’t there a chance he’d believe her now?
Sarah put a hand on his shoulder. Trying to protect him from the truth was a losing battle, she realized. The guy was too smart. It would be better to tell him everything. Then maybe they could put their heads together and figure out what to do.
“Sit down, Phil. I’m going to start from the beginning.”
He reluctantly dropped the printouts on his desk and lowered himself into his chair. “Now you’re going to tell me where you really found that sample?”
“No, I want to go farther back.” She pulled her own chair closer to his and sat down. “Remember our date, back when we were in grad school? The night we went to Señora Rosa’s and drank too many margaritas?”
Phil winced. “Unfortunately, I do remember it.”
“You spent a lot of time talking about the Star Trek movie that had just come out.”
“Please. Don’t remind me.”
“It’s okay, you were nervous. And you said some interesting things. There was one thing in particular I remembered afterward, about the high costs of space travel.”
“Sarah, what does this—”
“You said it was ludicrous to think we’d ever send a manned spacecraft to another star system, because the real technologies for interstellar travel were so much more difficult and expensive than the fictional ones in Star Trek.”
He raised his right hand to his chin and tapped a finger against his lips. He was thinking, remembering. “I admit it, I was a little obsessed with those movies. It just bothered me that they never explained how the starships were supposed to work. The starship Enterprise had this warp drive that magically bent the space-time around it, but to really do that you’d need to generate a substance called negative energy, and that’s just not possible in—”
“Yes, Phil, you were definitely obsessed. But I was impressed by how much you knew about the real interstellar technologies, like ion thrusters and nuclear fusion rockets. You said some of those technologies could conceivably propel a manned spacecraft all the way to another star, but they’d need enormous amounts of fuel, hundreds of thousands of tons. The mission would be so expensive it would bankrupt any country that tried it.”
“And I still believe that.” Phil’s voice was emphatic. He was so earnest, so damn serious, even when he was talking about Star Trek. “The costs would be phenomenally high because the distances between stars are so immense. To get from Earth to the nearest star in less than fifty years you’d have to accelerate a spacecraft to at least ten percent of the speed of light, and you know very well how difficult that would be.”
His cheeks flushed again. The topic of interstellar travel was enlivening him, waking him up. As Sarah stared at him she recalled the twenty-five-year-old Phil Clark who’d tried so hard to impress her at Señora Rosa’s. She smiled at the memory. “Yes, I know. But I remember something else you told me. You said the cost of the mission would depend on the weight of the spacecraft. A huge manned starship like the Enterprise would need to carry tons of food and water and recycling equipment just to keep its crew alive. But if you were going to send something smaller to another star system—say, an unmanned probe that weighed only thirty or forty pounds—you’d need much, much less fuel to propel it to high speeds. You said that was the only way to get the costs down to a feasible level.”
“I still believe that too.” He seemed pleased by the logic of his youthful arguments.
“That conversation made a big impression on me. The next day I did a little research and found an article in Scientific American that said some of the same things. It said you could design an interstellar probe to be as small as a basketball. It could be accelerated by any kind of propulsion system—fusion rockets, ion thrusters, whatever—and then decelerated at the end of its journey, when it’s approaching another star. If you wanted the probe to land on one of the star’s planets, you could program it to detach from the propulsion system and equip it with an aeroshell to slow its descent to the planet’s surface. Then it could start exploring.”
Phil raised an eyebrow. “But how much exploring can it do if it’s just the size of a basketball?”
“The probe would need only two systems, and both could be miniaturized. The computer system would store the probe’s instructions and maybe an artificial intelligence program for carrying them out. Computer chips are tiny, so they wouldn’t take up much space.” Sarah leaned forward in her chair. She was getting to the most important part. “The other system is an automated manufacturing setup. It would include miniaturized tools for mining the area where the probe landed. The tools would extract useful materials from the ground and feed them to a small manufacturing module, something like a three-dimensional printer. This machine would use the local materials to build more tools and bigger machines, and maybe solar panels to power the operation. The machines would eventually assemble a full-size factory that could produce everything needed for exploring the planet—rovers, drones, whatever. It could even build rockets for sending duplicates of the probe to other planets in the star system. In other words, the probe would be self-replicating.”
Phil turned away from her and glanced at the stack of printouts on his desk. He was thinking hard, making the connections. “This sounds a lot like the drill you mentioned before. That thing could also take molecules from the ground and incorporate them into its machinery, correct?”
“Yes, exactly. The material in the sample seems perfectly suited for the extraction and manufacturing needs of a self-replicating probe.”
He picked up the printouts and leafed through the stack, studying them again. Then he turned back to Sarah. “So you were telling the truth before? When you said you got the sample from a space probe?”
“It crashed a few miles north of here. Either in the Hudson River or Inwood Hill Park. The Air Force’s Space Command spotted it on radar and assumed it was a Russian probe, maybe some kind of space weapon. They forced me to sign a confidentiality agreement, and that’s why I was so cagy with you.”
Phil looked at her intently, his eyes narrowed to slits. “But you don’t think it’s Russian, do you?”
She shook her head. “According to the radar readings, the probe was only a foot across, not much bigger than a basketball. And before it hit Earth it detached from a larger object that was speeding across the solar system at sixty-five kilometers per second. This object couldn’t have been orbiting the sun, it was moving way too fast. Which means it probably came from another star system.”
She could tell from the look on Phil’s face that he understood. He got it. His Adam’s apple bobbed, as if he were having trouble swallowing. He clearly wanted to say something, but he couldn’t speak. And at that moment Sarah felt the same fullness in her throat, the same choking sensation. Now that she’d said the words out loud it was more than just a hypothesis. It was a hard, cold fact.
Her mouth was dry. She swallowed hard so she could tell Phil the rest. “The Air Force has been searching for the probe, but they haven’t found any sign of it yet, and I don’t think they will. It doesn’t want to be found yet. Its artificial intelligence program is making sure it stays hidden.”
Phil sat there for a while, still paralyzed. Then he looked again at the printouts in his hands and shuffled through them until he found the diagram of the lattice, the monstrous jungle gym of atoms. He held the page up in the ai
r and waved it. “So you think this alloy is part of an alien probe? It was designed by extraterrestrials?”
“You said it yourself, Phil. It’s unlike anything you’ve ever seen.”
“And this probe just happens to be following the same exploration strategy that was described in an article in Scientific American?”
“The laws of physics are the same everywhere, right? If interstellar travel is difficult for us, it’s also going to be difficult for everyone else in the galaxy. Any intelligent species, wherever they are, will be more likely to launch a small interstellar probe than a big starship. And the probe would have to be self-replicating if it’s going to do any useful long-term exploration.”
Phil grimaced. He was a scientist through and through, a man who’d trained himself to suppress his biases and look only at the facts, but in this case the facts were making him uncomfortable. His eyes darted from left to right, avoiding Sarah’s gaze. He seemed to be looking for an alternative, an opposing argument. “But what about the landing site? Why would the probe land in New York City if it doesn’t want to be found?”
“Well, let’s think about it for a second. Let’s try to look at it from the probe’s point of view.” She leaned back in her chair. “From the point of view of the probe’s computer system, I mean, or the artificial intelligence program that’s running the mission. Certain instructions must’ve been programmed into the system before the probe was launched.”
“How do you know that? You know nothing about these aliens, so how can you make assumptions about their computer systems and AI programs?”
“Give me a second, I’m just thinking out loud. I think we can reasonably assume that the extraterrestrials would have studied Earth with telescopes before deciding to send a probe here. That’s what our own astronomers have been doing for the past twenty years. They’ve used their telescopes to detect thousands of planets in other star systems, and now they’re planning to study the atmospheres of those planets to see if they have any oxygen or water vapor or other chemicals. In all likelihood, the aliens focused similar telescopes on Earth and saw the chemical signatures of life in our atmosphere. Then they might’ve taken a closer look at our planet and detected some of the radio and television signals we’ve broadcast into space over the past century.”