by Paul Mceuen
The students looked bored. Their indifference surprised him. The discovery that the natural world was mathematically explicable was, to Jake, the single most significant development in the history of humanity. From this followed the obvious consequence: the world was controllable. The constituents of the world—radio waves, apples, or planets—did what the differential equations told them to do. You learn to perform some formal manipulations of symbols on a page, and the next thing you know, you’re building radios that can communicate across oceans, or launching projectiles at your enemies with a precision that was terrifying to behold. It was that simple.
“What is it?” he repeated. “No guesses?”
“Nano,” came an answer from the front.
“You got it. Nano. The realm of the ultrasmall. Small has replaced big as the terra incognita for techno-explorers. The nanoworld is the new frontier.”
Jake clicked an icon on his computer and a color photo of an Intel Core 2 Quad processor chip appeared on the ten-foot-tall screen behind him. “A modern integrated circuit is the most complex and sophisticated piece of technology ever made,” Jake said. He clicked again, and the view zoomed onto a single transistor within the circuit. “This transistor is a thousand times narrower than a human hair. It is as much smaller than you as the earth is bigger than you. Distances in this world are measured in nanometers. Nano—from the Greek nanos, meaning ‘little old man,’ indicating one billionth. That’s small. One billionth of the population of the earth wouldn’t even fill up the front row of this class.
“The power of nano makes it possible to construct an entire world in the space of a meter,” Jake continued, as the image on the screen zoomed back out, the single transistor quickly lost in the rectangular maze of transistors, capacitors, and copper interconnects. “This computer chip is a world of doors and passageways for electrons, guiding them in a dance as intricate and involved as the daily movements of millions of people in any major city. An entire city for electrons can be built in a space smaller than a postage stamp.” The image faded and was replaced by an aerial view of the gridlike streets of Midtown Manhattan. “A circuit as complex as Manhattan could fit on the tip of my finger,” he said. “And unlike a real city, there are no traffic jams, no gridlock. All of it works flawlessly. Not a single packet of electrons out of place.
“In a computer chip, time is also miniaturized. Your computer can do operations—multiply two numbers, or communicate with its neighbors—about once every nanosecond. A one-gigahertz processor makes roughly a billion computations a second. Think about it. A billion in one second. You only live for, at most, three billion seconds. In only three ticks of the clock, a computer has as many thoughts as you will have in your whole life.” Jake stopped to let that sink in. “So every three seconds, your computer is like the entire population of Manhattan living a lifetime. And people wonder why it takes so long to boot up.”
A few laughs rippled through the students.
“Miniaturization was the most revolutionary force in the second half of the twentieth century. From Bill Gates to Gordon Moore, empires have been made constructing and controlling tiny electron cities that have lifetimes of thoughts in seconds. Computers, in effect, miniaturized our thoughts. But humans do more than think. What else do we do?”
“Sleep,” someone called from the back. More laughs.
“True enough. What else?”
“Move. We walk around.”
“Right. We walk. But walking is a pretty sophisticated form of locomotion. Let’s start with something simpler. What about crawling, for example? Can we make machines that crawl?
“Let me introduce a couple of my graduate students,” Jake said. He waved, and they came up on stage. “This is Joe Xu and Dave Gruber. They’ve got something to show you.”
Jake kept going while Dave and Joe set up. “How many of you have heard of DARPA?”
A few hands went up.
“DARPA stands for Defense Advanced Research Projects Agency. It’s a kind of military venture-capital firm—always on the lookout for the Next Big Thing. The Internet, the global positioning system, and the Predator Unmanned Aerial Vehicle, those were all DARPA projects. Most sink like a stone, but those that succeed can change the world.
“In 2004, DARPA hit upon a new way to drive innovation: the DARPA Grand Challenge competitions. These are open competitions where DARPA sets a goal and teams of scientists and engineers from around the country try and tackle it. The first one was to create a car that could navigate a desert racecourse without a driver. First prize was two million dollars. In 2004, nobody succeeded. In 2005, five crossed the finish line. By 2007, the challenge had moved from the desert to city streets, and people are now seriously talking about driverless cars on America’s highways. The lesson was clear: you throw money and talent at a problem, spice it up with a little head-to-head battle, and it’s incredible how fast innovation can happen.
“For their next competition, DARPA went small,” Jake continued. “The Grand MicroChallenge was to develop a robot smaller than a dime that could survive on its own in a woodland environment, without external guidance or power, for a month. The ‘woods’ consisted of a giant terrarium DARPA set up in a storage hangar at Fort Belvoir, near Mount Vernon in Virginia. The first year was a bust. Nobody got close, including our team. All the entrants ran out of juice long before the month was out. But the next year, with Liam Connor’s help, we won it running away.” This got their attention. Liam was a legend—the old man’s wrinkled face was easily the most recognized on campus.
Joe and Dave were nearly ready, and Jake retreated to the edge of the stage. Joe, whose real name was Xinjian, was a classic physics grad student, tall and thin, with wide eyes and a love for detail. He was in his fifth year, finishing his thesis on the mechanics of micro-robot locomotion. He already had an offer for a permanent position in Hong Kong but was holding out for a Millikan Fellowship at Caltech. Gruber was a little more unusual, a third-year muscular fireplug with a flair for public speaking—he’d done some acting as an undergraduate at Yale. Each had their part down pat: Dave handled the audience, and Joe handled the Crawlers.
Joe sat at the microscope set up on the corner of the stage. The scope’s video camera was hooked up to the overhead projector. Joe flipped a switch, and several in the class gasped. A giant creature appeared on the screen: a robotic spider-monster. It scurried to the left, then stopped, turned one hundred and eighty degrees on its six legs, and took off in the opposite direction.
“Say hello to a MicroCrawler,” Dave said. “Arguably the most advanced miniature robot in the world. And don’t worry, it won’t hurt you. The image is magnified a thousand times. It has jointed silicon legs that propel it forward, and a small microprocessor in its body that controls its movement. This one here is our smallest—about the size of a mustard seed. We have models ranging up to the size of a quarter. We build them at the Cornell Nanofabrication Facility using the same patterning, depositing, and sculpting techniques people normally use to make computer chips.”
Jake watched as the students stared at the Crawler, rapt. He smiled at Dave and Joe—the three of them had been through this routine dozens of times, but the spark hadn’t faded. Jake was proud of them. Jake had designed the Crawlers and oversaw the project, but Dave and Joe had done most of the painstaking detail work needed to make the designs a reality. Thousands of hours of struggle, failure, and more struggle. The three of them had gone through years of engineering, design, tweaking, and redesign in creating these little beasts. Doing something that had never been done before was brutally hard, like assembling a model ship in the dark. Make that a ship in a very small bottle in the dark. But they had done it. And—the glory of technology—done once, it could be done again, by anyone, anywhere. All you needed were the fabrication recipes and the right tools.
Joe adjusted the microscope’s optics, zooming out so the students could see the entire petri dish that corralled the tiny robots. Ten Crawlers sc
urried around while dozens more lay motionless, littering the miniature landscape. One hopped in a tight circle, like a fly with a wounded wing.
“What’s wrong with that one?” a student in front asked.
Joe said, “On this batch, we had a bad liftoff during step twenty. When we put down the piezo actuators.”
“Step twenty?”
“It takes forty-seven separate fabrication steps to make a Crawler,” Dave said. “Forty-nine for ones with a full communications system. It rivals Intel’s most complex computer chip. Five weeks of twelve-hour days to get through the entire process, assuming nothing goes wrong.”
“And something always goes wrong,” Joe added with a pained laugh. “It’s like walking a tightrope. Each step must be perfect. Make one little mistake, it’s all over.” He picked up a pair of tweezers and guided them toward the tiny creatures, the tips appearing enormous in the microscope’s field of view. He carefully brushed away the dead Crawlers until only the scurriers and the circler remained. “Let’s put you out of your misery,” Joe said as he grabbed the circler with the forceps. He applied pressure, and its body shattered into a hundred pieces. The students cringed.
A student in the second row raised his hand. Dave called on him.
“They seem like they’re looking for something.”
“They are.”
“What?”
“Lunch.”
Joe opened up a little box marked CRAWLER FOOD, removed a handful of corn kernels, and placed them on the glass slide. First one Crawler, then another, descended on the kernels, scissoring their scalpel-sharp legs, slashing through the kernels’ fibrous skin to the soft flesh inside. Joe zoomed in on one Crawler as it stuffed bits of shredded corn into the small feeding portal on its front. “We’ve made ones that can feed on almost anything you want,” Jake said. “Corn. Grape juice. A packet of sugar can keep one going for days. Each one’s got a genetically modified fungus that lives in its belly and converts a sugar source into ethanol fuel, courtesy of Liam Connor.”
“The issue with microbots has always been power,” Jake said, stepping back to center stage. “Quite a few teams built little robots like these for the first Grand MicroChallenge, but they all had the same weakness. They were powered by onboard batteries—tiny cells that run out of juice after a couple of minutes. And you can’t load them with more batteries—they’d be too heavy to move. It was a showstopper. Everyone was stuck.
“Enter Liam Connor. He said to me, ‘No problem, my boy. You just have to teach the little fellows to eat.’ ”
Jake let that settle in before continuing.
“His idea was to create a fungus that could serve as a digester and convert food to energy. He started with something called Ustilago maydis—a fungus that lives on corn, and he added some genes from brewer’s yeast—the stuff that converts sugar to ethanol when you make beer or wine. The Crawler eats by shredding bits of food with its legs and stuffing them into a feeding portal. That portal—its mouth—leads to its stomach—a little chamber filled with the fungus. The fungus breaks down the food and voilà! Fuel. The fuel powers the Crawler, and the Crawler eats some more. It can keep going as long as the food holds out. We call them HungryCrawlers. And they are champions.”
“So what did you do with the DARPA prize money?” a student called out.
Jake laughed. “I still have my share, sitting in the bank. Joe?”
“I bought a house for my parents in China.”
“Dave?”
“I bought stock. Mostly Google and Intel. And a Segway.”
Jake said, “It’s a hazard. He rides it up and down the halls.”
A hand went up, a student down in front, wearing a red Windbreaker and matching high-tops, no more than eighteen years old. “What about intellectual property?” he asked.
“We’ve got seven patents filed,” Jake said. “Three have already been granted.” Jake was always amazed at how quickly the thoughts of today’s students went to the business side. Fifteen years ago, when he was an undergraduate, no one thought about IP, about patents. Now it was different. Kids saw dollar signs everywhere.
“Anyone license it yet?”
“Quite a few. A start-up in Boston wants every home in America to have MicroCrawler mini-Roombas running around. On countertops, walls, ceilings, cleaning away everything from crumbs to cobwebs. A medical technology company in North Carolina hopes to use them as remote surgeons that can work on a patient from the inside, excising tumors or clearing blockages without the need for incisions or the risk of infection. But our biggest suitors are a couple of military contractors. Micro-robotics is going to be the next big thing in warfare. That’s why DARPA ran the Grand MicroChallenge. Small spies, tiny assassins, things like—”
A cellphone went off. Jake was annoyed but not surprised. This happened at least once a class. Jake spotted the culprit fishing the phone out of his pocket. He did his best to shame him with his stare.
The student didn’t notice, fixated on the screen of his phone, an expression of shock on his face. What he did next surprised Jake. He whispered to his neighbors, got up, and headed for the door.
As he was working his way down the row of seats, another student pulled a phone out and started working it with his thumbs. He looked around, whispered to his friend, pointed to the door.
That’s when it really got going. Two more cellphones started ringing. Five times that number silently fished phones out from bookbags, pocketbooks, and knapsacks. More people began to leave. Jake had never seen anything like it.
He glanced at Dave and Joe. Both shook their heads, not knowing what was happening. Dave flipped open his own phone.
A couple of students near the back got up, talking louder now. “It’s Liam Connor,” one of them said, loud enough for everyone to hear.
“What? What about Liam Connor?” Jake asked.
“They just found a body in Fall Creek Gorge,” the student said.
“And?”
Dave closed his phone, face white. “Jake, this can’t be true. They’re saying that the body is Liam Connor’s.”
5
THE HILLS ON WHICH CORNELL UNIVERSITY STOOD WERE the remnants of the glacial moraine left over from the last ice age. Streams cut through this loosely packed earth and shale until they reached older, solid rock, carving the dramatic gorges and waterfalls for which the campus was famous. Fall Creek Gorge was the deepest, a huge gash in the earth defining the north boundary of campus. It was spanned by a narrow suspension footbridge linking the central part of campus to the houses and dorms farther north. From its midpoint, it was a two-hundred-foot plunge to the rushing waters of Fall Creek below.
Jake always brought the students here later in the semester when he taught “Physics for Presidents.” They stood on the bridge and stared at the water below while Jake gave them a rundown on the geology, describing the advances and retreats of the glaciers that carved out the gorges. Then Jake would give them a little demo. He would take a watermelon and drop it off the bridge. They’d all time it with their watches, the seconds ticking by until it burst on the stones below. Three-point-two seconds was the average answer. They’d compare it to what Newton predicted.
But the real lesson wasn’t Newton’s laws, the acceleration due to gravity, v2 = 2gh. That was a cover. Jake had worked up this field trip after he had lost a student to suicide. Jake knew the statistics. Over the past twenty-eight years, sixteen students had jumped from this bridge. It was a painful fact about a pressure-cooker school like Cornell, but it had hit Jake hard. He still couldn’t forget the parents at the funeral. No parent should ever have to go through that. No kid should ever put their parents through that.
The real lesson of the watermelon was about the violence of falling. The melon splattered, bits of red flesh streaking out like the sun from the point of impact. Potential energy turned into kinetic, velocity growing with every second of the fall. He brought the class here every semester to see what would happen when you
went over. Cut through the romanticism and get down to the reality. You jump, you fall, you hit.
Three-point-two seconds. Blam.
MORE PEOPLE WERE ARRIVING BY THE SECOND, MORE STUDENTS, more faculty, more police. They were coming from all across campus. Jake had joined the rush, running over from the Schwartz Auditorium lecture hall. If it truly was Liam Connor, Jake didn’t think it would stop until the entire campus was clustered up against the gorge.
Liam Connor was an icon. He’d been at Cornell for sixty years, was known to every student, faculty member, and alumnus. He was in many ways the face of Cornell, the last of the pivotal scientists—people like Hans Bethe, Richard Feynman, Carl Sagan, and Barbara McClintock—who had turned a sleepy central New York town into one of the most important centers of science in the world.
Jake kept flashing to the last time he’d seen Liam—yesterday, lunch at Banfi’s. They were both in a hurry. They’d chatted about a recent experiment; a guy at Caltech had come up with a way to make a strand of DNA assemble itself into a smiley face only fifty nanometers across. Not just one but billions and billions, all floating around in a single little test tube. “The most concentrated solution of happiness ever made,” Liam had joked. Liam was beaming. His own discovery, someone else’s, Liam barely seemed to notice the difference. He loved every new development, every step up the scientific ladder.
There was no way that Liam Connor had jumped from that bridge.
DOZENS OF PEOPLE PUSHED AGAINST HIM, CROWDING FROM all sides. Jake’s stomach churned. He hated death, despised it. Not in the way most people did, ones who mostly feared it. Jake hated it as an enemy. Hated what it took, what it left behind. Jake was in the Army for four years, a time that included the First Gulf War. No soldier spends time in a war zone without getting to know death’s sight and smell. But familiarity had bred contempt. Jake found death to be a colossal waste. Someone’s alive, and then not. It was sudden. Stark. Irreversible.
