George and the Unbreakable Code

by Stephen Hawking

  Ever the scientist and teacher, Eric couldn’t help reading out a few lines:

  “One oxygen bonds with two hydrogen to form H2O… . Excellent,” he murmured approvingly. “Well done, you two—it’s good to see you working so hard. Thank goodness for you—the rest of the world seems to have gone bananas, and I’m at my wits’ end trying to sort it out.”

  “Oh yes, well done,” said Annie’s mom, admiring the on-screen project. “At least I don’t have to worry about you and George. That’s such a relief. I think I’d go crazy if I had anything else to stress about right now! It’s chaos out there. I had a horrible time doing the shopping. I can’t believe anyone else has nine family members arriving from Australia, but people were buying up supplies as though they did. Someone accused me of being a hoarder!”

  Annie and George exchanged glances and sighed. Clearly the adults were going to be of no help whatsoever.

  “Dad … ,” said Annie. Eric was busy rifling through various drawers in his study. “What’s going on?”

  “Annie, honestly, we don’t know,” he said. “Computer systems all over the world are sporadically malfunctioning, and nobody can find out why. Our best guess is that somehow, all internet security protocols have been breached, messages intercepted, and rogue commands are being given—with some pretty extraordinary results.”

  “Like what?” said Annie. “The free flights?”

  “Yes, but also a dam opened in the desert,” said Eric. “Its computer systems caused the gates to open, so all the water has now flooded out. Drones—you know, those computerized aircraft the army uses—are refusing to take off. A whole bunch of computer networks have gone down too—the ones that let people chat to each other online. That’s probably not so bad, compared to everything else. But food deliveries are being affected, and we’re worried that power supplies might be next.”

  “Do you think someone is hacking into all the computers in the world?” asked George.

  “We don’t know!” Eric burst into stressy-sounding laughter—the sort of laugh grown-ups use when things aren’t really that funny. “It is literally unbelievable. But it looks like every system in the world has been hacked into! Speaking face-to-face is the only safe form of communicating now!”

  “Even cell phones?” said Annie.

  “Yup,” Eric confirmed. “Everything. It seems that every system in the world is vulnerable.” He unplugged the spare hard drive from Cosmos—the one that George had been using to check Cosmos’s systems. “I’ll take that with me, just in case I need to reference anything from Cosmos while I’m away.”

  “Who could be doing this?” George wondered.

  “We don’t know,” said Eric soberly. “It could be an individual, it could be a rogue state, it could be a corporation. Some people think that, given how random the targets are, it might actually be space weather. One or two people are speculating that this is alien interference—we’re not able to trace any signal to a location on Earth.”

  “What do you think?” said George.

  “Me? I’m afraid my hypothesis is not very popular.” Eric grimaced. “I think that someone has managed to develop a quantum computer and is using it to break into every system on Earth. But who it is and how they could have managed it when we can’t do it ourselves, I can’t tell you, because I simply don’t know. But I don’t like it … not one little bit. And now I have to go.”

  “But where?” cried Annie.

  Eric sighed, ruffled her hair, and kissed her on the forehead. “I can’t even tell you that. There’s a car waiting for me outside.

  QUANTUM COMPUTERS

  Dr. Raymond Laflamme

  Computers have become an integral piece in almost all aspects of our daily lives. Today’s computers are in our homes and our cars, and most of us carry one with us everywhere we go in our mobile devices. This technological revolution was made possible by our understanding and harnessing the properties of the world around us. At the heart of that understanding is mathematics.

  A challenge for mathematicians

  In 1900, a German mathematician—David Hilbert—posed a list of 23 problems for mathematicians to solve. When British mathematician Alan Turing worked on one of the problems, which asked mathematicians to find out if we could always discover if a mathematical proposition was true in a finite amount of time, he tackled it by proposing to build a hypothetical machine that would derive theorems in a mechanical way. This machine became known as a Turing machine, and was a blueprint for today’s computers.

  Classical vs. quantum

  Scientists like Galileo, Newton, Maxwell, and others described the world around us to high accuracy, coming up with the theories of classical mechanics. But when scientists began working at the scale of atoms and molecules, classical approaches broke down and they needed a new set of theories and rules: quantum mechanics.

  These rules are very different from those of classical mechanics. For instance, the superposition principle states that if A is a solution of an equation of quantum mechanics and B is also a solution, then A+B is also a solution. What does that mean? In the case of an electron, it means that if we have one solution with an electron here, and another solution with an electron there, we can have a solution with a single electron being here and there at the same time. Pushing this possibility to its limits led the physicist Schrödinger to show that at the quantum level we could see a cat alive and dead at the same time—something we certainly don’t see at our scale!

  Using quantum principles with computers

  1. First we transform information into a quantum bit, or qubit for short—and this can be in the state 0 and 1 at the same time!

  2. If we have two qubits, they can therefore be in four states: 00, 01, 10, and 11. Now imagine three qubits: 000, 001 … 111: a total of eight states.

  3. You can see that the number of states grows exponentially with the number of qubits. Just by changing the classical “or” (0 or 1) to a quantum “and” (0 and 1), we can have exponential increase in our computing power!

  4. This means that if we change the rules with which we compute, we can drastically change the type of problems we can solve too, though quantum computers would not necessarily have an advantage for all problems.

  5. For some problems, quantum computers therefore are formidable devices. An example is in factoring large numbers—the basis of most of today’s cybersecurity—where a quantum computer would be able to solve factoring problems with ease and break encryptions. They will also be applicable in other complex disciplines such as materials science, chemistry, drug design, health care, and much more that we have not yet imagined.

  Quantum mechanics has provided a key to understanding the very building blocks of our world. Quantum information science gives us an incredible opportunity to harness the power of quantum mechanics for the development of mind-boggling technologies such as the quantum computer, quantum cryptography, quantum sensors, and more that have not even been imagined today.

  But I’m sure you’re safe here—we’ll get this sorted out within the next few hours.”

  “But what are we supposed to do?” asked Annie.

  “Um … write your chemistry project!” replied Eric. “You finish that off, and when I get home, I’ll look forward to reading it.” He paused and typed a few commands on Cosmos’s keyboard. “I’ve given you permission to use Cosmos for your chemistry project … but just to make sure you’re safe, I’ve cut your access to any other function. He will only operate for you on matters related to your homework. I can’t imagine that will generate any interest from a malicious computer hacker, if that’s really what this is.”

  George felt his spirits sink.

  “Wait!” said Annie. “So you’re not taking Cosmos? Or Ebot?”

  “No, I don’t think so,” said Eric. “I’ll travel without my digital footprint.”

  With that, he charged out of the study, hot on the trail of another great scientific mystery that he hoped to solve befo
re anyone else. As he shot down the hallway, he cannoned into his wife; he tried in vain to hug her—she was carrying armfuls of spare bedding, so his arms didn’t reach round her. Instead, he just managed to kiss the top of her nose and then disappeared through the front door.

  “Annie!” called Susan. “Can you help me? We need to make up lots of beds.”

  “Why don’t they camp in the garden?” said Annie. “It’s not cold, and they’re always telling us on Skype about their adventures in the outback.”

  “Brilliant idea!” said her mom. “Can you find the tents and start pitching them?”

  “Yes—leave it to me!” Annie replied.

  George said to her quietly, “We didn’t get to ask your dad about IAM and the robots. Or QED. Or Cosmos. We didn’t get a chance to ask him anything!”

  “I know!” She sounded annoyed. “But what could we do? He was here and then he was gone—and we couldn’t really start talking to him in front of Cosmos.”

  “And,” said George, “he’s taken the hard drive that I was using to check Cosmos. We would have been able to tell if he had been hacked into, and if that’s what’s making him so weird. But now we can’t know for sure …”

  “You’d better go,” said Annie. “Unless you want to help canvas over my garden. Let’s meet later and I’ll see if I can find anything out while you’re gone.”

  • • •

  When George got home, his mom and dad were looking perplexed. On the table was a loaf of Daisy’s bread, which they were studying earnestly. He waited for an explanation, but they just stood there, gazing at the burned and very solid-looking rectangle sitting on the table.

  “Er, Mom and Dad … ,” said George; from the lack of noise in the house, he realized that the twins must already be in bed. “ ’Scuse me for asking, but why are you standing staring at a loaf of bread?”

  “We’re wondering,” said Terence, “why someone offered us a thousand pounds for this loaf of bread earlier today.”

  “And you didn’t sell it?” cried George. “That’s got to be a once-in-a-lifetime opportunity!”

  “I’m not sure about that,” said his mom gently. “We took our turn at the cooperative today, and people kept coming in with whole wheelbarrows of money to spend on buying our food.”

  “But the cooperative doesn’t accept money!” said George. It was a venture his parents were involved in: people exchanged goods and services without any money changing hands.

  “That’s what we said,” replied Terence. “But it looks as though there’s no food anywhere!”

  “So now people have got lots and lots of money from the bank machines,” added Daisy, “but nothing to spend it on! So we’ve decided to keep our bread and not to sell it, because money doesn’t seem to be worth anything anymore.”

  “We just can’t get over someone wanting to spend a thousand pounds on a loaf of your mother’s bread!” said Terence with a rare glint of humor.

  At that moment, with a gentle fizz and a plop, all the lights in the house went out.

  The three of them stood there in the gloom. “The babies!” cried Daisy, trying to fumble her way toward the stairs.

  “They’ll be fine,” Terence reassured her. “It’s just a power outage. Or perhaps my wind panels have come unstuck.” George’s family tried to use only the energy they could produce themselves from their own wind generator, but they were still connected to the electric grid as well.

  Blundering about in the darkness, George found the back door and peered out. The only light was coming from the stars in the sky. He realized how late it must be. “It’s everywhere!” he exclaimed. The lights had gone out all over Foxbridge. George reflected that this would be an amazing night to take a photo of Saturn: there would be no light pollution at all. But he didn’t have much time to dwell on this idea, as his dad decided it was time to become a man of action.

  “George,” he announced, “I’m going to head up onto the roof, but I’ll need your help. I want to check out our turbine. It should have kicked in, but it hasn’t, so there must be a problem. We should be able to generate enough power to get our lights back on, even in a power outage.”

  Finding their way through the dark house with George’s pocket flashlight was a surprisingly spooky experience. In the darkness, even familiar objects were scary. The cupboard where George’s dad kept his toolbox looked like it would open its jaws and swallow his dad whole. The stairs were a flight of steps in Dracula’s castle. A chest of drawers on the landing had turned into a looming tombstone, and the ticking of a clock sounded like the chimes of doom. George was glad that his dad had gone ahead and that he could hide behind him, in case anything really scary jumped out at them. Even the gentle snores of his baby sisters had started to sound like the heavy breathing of zombies lying in wait for their prey… .

  Upstairs, they tiptoed through the twins’ bedroom, and climbed out the window and onto the roof. George saw that his dad was right—one of the wind panels had come adrift.

  Most of the time the generator worked quite well. George and his dad were rightly proud of their efforts: the turbine used wind power to move a magnet around an arrangement of copper wire, generating a modest amount of electricity. It was just a shame it seemed to have fallen apart when they really needed it.

  George balanced on the broad window ledge, holding on to the toolbox, while his dad climbed up onto the roof above the attic window, where the wind panels lived. Suddenly he saw a flashing light coming from his tree house. He squinted over to try to make out what it could be. Why would there be a light on there? It didn’t make sense. He stared at it again—it looked like a flashlight being switched on and off.

  “Hammer,” instructed Terence, perched on the sloping roof.

  George obligingly handed it up to him. He didn’t dare tell his dad to look over at the tree house: if he twisted round, he might fall off the roof. So George watched in silence as the flashes came and went, some quick, some slow. After a few moments he realized that there was a pattern to them: fast, fast, fast; slow, slow, slow; fast, fast, fast.

  “Dad?” he said cautiously as his father thwacked himself on the thumb with a hammer.

  “Youch!”

  George heard noises from the other side of the house: some passersby were hurrying along the road. “I read on a website that someone captured a werewolf,” one of the unknown people said to another, his voice carrying very clearly on the still night air.

  “What is it?” Terence now had his thumb in his mouth.

  “What does three quick, then three slow, and then three quick flashes with a flashlight mean?”

  “That’s Morse code,” said his dad through a mouthful of damaged thumb. “It means ‘SOS.’ ”

  Who would be sending an SOS from the tree house?

  “Dad,” he said casually, “do you know any more Morse code?”

  His father, preoccupied with the wind panel, didn’t seem to think this was an odd question. “I’m putting on my headlight,” he said, switching on the small bulb attached to his forehead by a band of elastic. “Your flashlight is wobbling all over the place. Yes, I do know Morse code. Learned it years ago. It was the kind of thing your grandfather was very excited about.”

  “Can you do D-I-K-U?” George asked eagerly as Terence hammered away.

  “Hmm … Dash-dot-dot …” His dad aimed the hammer at the innocent nail, his strokes keeping time with the dots and dashes. “Dash dot dash” (Long tap—short tap—long tap). “Dot dot dash” (Short tap—short sharp tap—long tap with flourish at the end). He finished hammering. “What are you doing?” he asked as George transferred his instructions to flashes on his flashlight.

  “Just practicing,” said George earnestly. “How’s the generator looking?”

  “Nearly there.”

  The reply from the tree house came quickly. “Dot-dash. Dash-dot-dot-dot,” George repeated out loud. “Dad, what does that mean?”

  “Erm, let me think …” Ter
ence was now holding two nails between his lips but speaking at the same time. “That makes AB. Arrgh! I think I’ve swallowed a nail! I’m choking!”

  George reached up to thump his dad on the back, and a tiny tack popped out of his mouth.

  AB. Annie Bellis. SOS. From his tree house.

  “Dad, are you done?” George swiftly shone the flashlight on the wind panels, which had started moving again.

  “Are you in a hurry?” Terence was surprised.

  “I’ve got to go to my tree house and take a photo of Saturn,” explained George. “Before the lights come back on.”

  With that, he nipped back through the open window, past his sleeping sisters, down the stairs, out the back door, and up the ladder to his tree house.

  Sure enough, the SOS was waiting there. Even in the darkness, Annie looked panicky.

  “What were you doing on the roof?” she asked.

  “Mending the wind generator,” replied George. “With my dad. He hit his thumb and then swallowed a nail—that’s why he was shouting.”

  “Wow, your family is weird.” Annie was huddled into George’s beanbag, arms wound tightly around her knees.

  “Er, I don’t think you can talk,” said George. “Who’s got a fake robot dad? And loads of relatives arriving on free flights from Australia?”

  “Okay,” said Annie. “You win. We are way weirder. Anyway,” she added as the lights came back on in George’s house, now the only one in the row that wasn’t dark, “you guys win in another way. You might be the only people in Foxbridge with electricity.”

  “It’s just a power outage,” said George. “Isn’t it?”

  “I don’t know! Dad said not to use the Internet, so I can’t check what’s going on in other places. D’you remember, he said we shouldn’t use cell phones, either, but I don’t know if we even could—my signal keeps cutting out.”

  “Is that why you’re sending messages to me in Morse code,” asked George, “from my own tree house?”

  “Yeah,” said Annie. “I thought it would be like WhatsApp, old school! Enigma-style texting. I didn’t know if you’d crack it, but you did!”