George and the Unbreakable Code

by Stephen Hawking

  “Yup.” George was amazed at his own confidence. “We’ll tell Cosmos we need to work on the next element of life, and then we’ll send Ebot through the doorway… . Ebot is wearing your Dad’s space suit already, so the fact that your dad is traveling through the space portal should be broadcast out there. Isn’t that how I AM found us before?”

  “You’re right!” Annie got Cosmos out of the bucket, brushed off some lettuce leaves and a small slug, opened him up, and pressed the power button.

  “Do we need our suits?” asked George.

  “Um, we might,” Annie realized. “It depends. But they’re in Dad’s study.”

  George was already letting down the rope ladder.

  “You can’t!” she squeaked. “It’s too dangerous! What if they come back?”

  “I’ll be very quick,” said George confidently. “Get Cosmos working and open up the portal. I’ll be back in a nano-flash.”

  “Okey-doke,” said Annie as he disappeared from view. “Let’s get this show on the road … Cosmos!” She took a very deep breath as the computer came to life. “I want to carry on with my chemistry project. I want you to look for amino acids in space. I want you to summon the space portal and open the doorway onto a comet in the Solar System where I can find amino acids, which are the building blocks of life.”

  George scrambled back across the empty vegetable patch and went through the fence into the mysterious dense jungle of Annie’s back garden. He ran up the path, but suddenly stopped in his tracks. The back door of the Bellises’ house had been ripped off its hinges and thrown to one side. All the windows had been smashed. George picked his way across the broken glass and into the house, and found the furniture overturned, the refrigerator door hanging open, and the cupboards ransacked. Bags of flour and sugar, which had clearly burst when they’d been snatched out of the cupboards, lay on the floor, spilling their contents all over the terra-cotta tiles. Someone had stomped on a bottle of lemonade, which had sprayed across the cupboards and floor, mixing with the flour and sugar to form a gooey mess. Nearby lay a row of empty plastic tubes that looked like they belonged in a lab, not in a domestic refrigerator. The contents of these tubes seemed to have leaked out and joined the sticky lake on the floor, giving it a greenish glow. It looked as though Eric and Annie’s experiments had met an untimely end.

  “Urgh!” George tried to pick his way across the slimy floor, but he slithered on broken egg mixed with jam—which catapulted him across the kitchen, into the cold arms of the open refrigerator.

  “Ow, ow, ow!” he muttered to himself, rubbing his nose, which had collided with a shelf. All the food was gone, even the old jars of unwanted jam and mustard that usually lived at the top. Someone had reached into the fridge—and the freezer and all the cupboards—and swept out the contents, leaving behind only the damaged items, which had been thrown onto the floor to make a horrible soup of nasty fizzing sticky chemicals and food.

  George gingerly edged his way across the kitchen, but stopped when he noticed Susan’s phone surfing on a pile of gunk in the corner. Somehow, in all the chaos, her lost phone had managed to reappear—if he could reach it, he could try calling Eric!

  Eric never knew what to do in normal situations—there was no point in asking him how long you should boil an egg for or who was number one on iTunes. But he was at his best when great cosmic accidents happened, or when the world was threatened by evil, or when an alien appeared. In those circumstances, he was more useful than anyone else in the whole world. Right now, it would be really handy to know what Eric thought was going on.

  George tried to make his way across to the phone to find out if it still worked. But almost immediately he skidded, his arms flailing, looking like a surfer trying to negotiate a huge wave. As he crashed into the kitchen cupboards on the other side of the room, he realized that he was wasting precious time. In the distance he heard a roar—the same sound they had heard before the looters swept across the gardens, plundering each house as they went. It might only be minutes before they returned, desperate to scavenge any scraps they’d missed the first time around. George slithered his way round the room, feeling as if he was ice-skating, and decided to give up on the phone. This time, he teetered into the hallway and headed toward Eric’s study.

  Of all the rooms in the house, the study seemed to have suffered the least damage. It must have been ignored by the mob. A few books had been pulled off the shelves, but otherwise the room was untouched. George quickly found what he was looking for: a couple of space suits, along with all the equipment that went with them. But how could he carry everything? He decided to put on the spare suit and boots. The space boots were so big, he could fit them on over his ordinary shoes. Zipping himself in, he tied the arms of the other suit around his neck, looking as if he was carrying a very floppy person on his back. Then he put on a pair of space boots and clipped another space helmet around his wrist along with the other pair of boots. He stomped out of the study in the heavy space boots. They had far more grip than his sneakers, and he crossed the slippery kitchen floor easily, without falling over once. He marched out of the house and back across the garden, a space suit fluttering behind him like a flag, not noticing that some of the chemical ingredients from the kitchen floor had decided to come with him.

  Up in the tree house, Annie had switched Cosmos off to save power, and arranged things on the platform so that Ebot could step through the space portal without falling out of the tree. While she was doing that, she kept a worried eye out for George. There were no grown-ups around now if anything went wrong. Cosmos was more like an irritating know-it-all older cousin, and could now no longer be relied on to help them. She and George really were on their own in a strange and hostile world. The only person—and he wasn’t even a person—on their side was Ebot, and in the end, he would do whatever he was ordered to do, no matter what that might be. He wasn’t able to distinguish between what he should and should not do.

  While she was waiting, Annie heard a scuffling noise, which made her draw in her breath sharply. Screwing up all her courage, she peered over the edge of the tree house. As soon as she saw George climbing the ladder in his space suit, with the other one flying out behind him, she gave a deep sigh of relief.

  George stomped across the platform and threw down the space gear.

  But Annie was perplexed. “What’s that on your space boot?” Annie was pointing to a glistening blob of glowing slime.

  “It must be from your kitchen floor. But—hang on … it looks like it’s moving!” George realized. “It’s like it’s alive!”

  “What slime? Where did it come from?”

  “What does your dad keep in the refrigerator?”

  “Dunno for sure,” Annie replied. “He had some experiments sealed in test tubes on the refrigerator door, but he said I wasn’t to touch them—ever.”

  “I’d just like to know what this weird stuff is, and why it seems to be spreading,” said George.

  “It’s probably that protein gunk that Dad grew in space,” Annie told him. “He does that—he goes to space to grow stuff that doesn’t grow as fast on Earth. Now, listen, can we get on with things here?”

  “Okay, then … what now?” George turned to gaze anxiously across Foxbridge. It seemed quiet and still again, but they knew from experience how quickly that could change.

  “Amino acids,” said Annie decisively. “They’re the next ingredient in my recipe for life.”

  George looked down at his boot. He was sure the slime had moved again, but it didn’t seem the moment to mention it; in terms of priorities, it wasn’t number one.

  “Where do we find them?” he asked.

  “I’ve given Cosmos the command”—with the computer turned off, she was able to talk freely—“to find a comet in our Solar System. Comets are just the kind of place where we might find tiny amounts of amino acids. And it’s the ideal location for Ebot to be kidnapped, especially if we dress him in Dad’s space suit and make him u
se Dad’s space call sign. He’ll be obvious, just sitting in the middle of a comet! If I AM is monitoring all computer activity, Dad or Ebot’s presence in space should be noticed straightaway.”

  “Brilliant!” said George. “But will they be able to pick him up from a comet, rather than the Moon?”

  “Well, how would I know?” Annie sounded tense. “We’ve just got to try it; if it doesn’t work, I’ll have to persuade Cosmos that we need to look for amino acids on the Moon. That would be a bit awkward, as I don’t think there are any. Let’s put our space suits on too!” she added.

  “Annie, are we actually going into space?” asked George. “We can’t use Cosmos’s space portal again—it’s not safe.”

  “No, I agree.” She nodded. “But do you remember last time we were on a comet? It didn’t have that much gravity. If Ebot lands there, he might just fall off and drift through space.”

  “Yeah, good point,” said George. “What are we going to do about that?”

  “We put on our space suits,” said Annie decisively, “and just kind of reach through the doorway so we can peg him down onto the comet without actually stepping through ourselves. How about that?”

  “Okay, I get it!” said George. “It’s good.”

  Annie quickly got dressed in the space suit George had brought for her. “Let’s get that portal open,” George instructed Annie.

  She pressed the command on Cosmos’s keyboard.

  “Greetings,” said the great computer; it sounded as if he was smirking. “How may I assist you?”

  “We’re ready for you to open a space portal onto a comet in our Solar System so that we can investigate amino acids in space for my chemistry project,” Annie reminded him, shoving her feet into the space boots. “We—that is me; my friend George; and my father, Eric, who is just over there—would like to use your space portal for our research.”

  “Eric?” said Cosmos in some excitement. “Eric is going into space?”

  The friends glanced at each other—would this work?

  “Yes, that’s right,” Annie confirmed. “Can you make that happen for us?”

  “Affirmative,” replied Cosmos. “I have already located a comet in the region of Jupiter.”

  “Okay.” Now entirely encased in her space suit, Annie saluted George. She propped up Ebot and held him at the ready.

  George wondered about the probability of their plan working. Now, instead of having a normal vacation, he was about to push an android through a space portal onto a comet near Jupiter as a decoy for his best friend’s dad. It was all so strange … better not to think about it too deeply or he would begin to freak out entirely.

  “We won’t be long,” said Annie. But she sounded very nervous too. “We just have to collect the amino acid sample and then return to Earth, okay? There’s no need for you to even close the portal door behind us. In fact, I’d like you to leave it open. My father might walk out onto the comet, but George and I won’t. Will this work with your rules? You won’t try and blow us up again, will you?”

  “Provided one passenger passes through the portal,” said Cosmos, “there will be no errors of that description.”

  The portal glowed, and gradually became a solid object through which the three of them could walk. The door opened, and they saw a grayish-white, rocky expanse. On either side of Ebot, George and Annie prepared themselves to step through.

  “Remember, the gravity will be lower!” Annie whispered out of Cosmos’s hearing. “So push Ebot through, and we’ll hold him down on the comet, hammer in the space pegs, and let go.”

  “Got it!” said George. “Good luck in space!”

  With that, they shoved the android in front of them, through the doorway, and onto a comet. A comet in orbit around Jupiter, the most magnificent planet of all.

  The last time George and Annie landed on a comet, they had fallen through space toward it, traveling in great circles until they touched down on the surface with a bump. That was on their first ever space journey together. Annie had opened up the space portal in a fit of pique, to prove to George that she knew how to fly in space. It had been the start of George’s cosmic journeys; an amazing beginning to a series of strange and wonderful adventures.

  But this time the space doorway didn’t deposit them above the comet; it opened right onto the comet itself—and to George’s relief, they were able to push Ebot through, exactly as planned, onto the crunchy, rock-strewn ground.

  As soon as the android passed through, they felt the effects of the much lower gravity. He immediately flew up into the air, and they had to drag him down to the surface. The robot looked at them, a quizzical expression on his face visible through the space helmet. They knew it was impossible, but they wondered if it was an expression of betrayal; if he knew what they were up to.

  “Here—quickly.” Annie passed some space pegs, a tiny space hammer, and a length of space rope, which came as standard issue in each space suit, over to George. “You jam a couple of pegs into the surface—try to tie him down so that he doesn’t float away.”

  It reminded George of helping his father fix the wind turbine. He carefully let go of Ebot and knelt down to thwack a couple of pegs into the crumbly surface of the comet, one on either side of the portal, waiting for the back kick of the reaction as he hammered. The android’s legs were now floating around in the air, while Annie clung on to him from behind.

  Neither of them were in the mood for sightseeing, but even so, they couldn’t help noticing the extraordinary close-up view of the biggest planet in our Solar System. However crazy and dangerous their current predicament had become, Jupiter wasn’t something they could ignore. It hung before them, dominating the starry backdrop like a vastly outsize ball on which someone had painted an uneven row of tiger stripes.

  “It’s so … so Jupiter-ish!” George heard Annie’s voice whispering through the voice transmitter in his helmet. “How did they know, hundreds of years ago, that it would be exactly the right name for it?”

  “It’s so red!” said George, taking a quick break from hammering in order to study the red spot—the storm that had been raging on Jupiter for over 300 years. Astronomers on Earth had been able to see it through telescopes for centuries, but he and Annie could now see it right before their eyes, and turning like a whirlpool of orangey red, against the distinctive cream-and-brown stripes of the mighty planet.

  As George gazed at the awesome sight, he realized that Ebot was starting to drift away from the space doorway again.

  “Hurry up!” Annie whispered, struggling to hold on to the robot.

  “Done!” George said, winding a length of space rope around the pegs and then tying it to Ebot’s suit loops, as though he was a helium balloon back on Earth. “You can let go of him now!”

  As Annie watched Ebot, silhouetted against the backdrop of Jupiter, she had a strange thought. When they traveled into space, they usually regarded going home as a journey back to safety, to what they knew best. This time things were very different. This time they both felt freer and safer in space than they had on Earth.

  She pulled herself back through the space portal. “Oops—we nearly forgot the main thing!” she exclaimed. “We have to get Ebot to use Dad’s call sign so that anyone who is tracking interspace communications thinks that he’s in space. We don’t know what Cosmos is passing on, so we need to make sure that I AM knows he is there.”

  “I can’t believe we forgot about that!” said George. “Quick—call Ebot and get him to reply.”

  “E-Eric,” said Annie. “Can you reply to my signal?”

  “Yes,” replied the robot.

  “Are you in space?”

  “Yes,” said the robot again.

  “Are you on a comet?”

  “Yes.”

  “How long can we keep the doorway open?” George whispered to Annie.

  “Not long,” she admitted. She checked Cosmos’s battery life. It was running down fast. She tapped a few keys and zoomed
the space portal out, so that Ebot seemed farther away.

  They watched him through the doorway for a few more minutes, but they were both horribly aware that it was getting much darker on planet Earth now. Even though it was early summer, and the northern hemisphere received much more daylight than it did in winter, the light couldn’t hold for much longer; they realized that it was getting dangerous for them to stay outside. Cosmos and the space portal gave off a considerable glow, which, once it got dark in Foxbridge, would be all too visible and make them a target if the mob returned.

  “I think we’d better shut down the portal,” said George reluctantly. “Anyway, Cosmos has hardly any battery life left. Space travel drains him of energy.”

  They took one last lingering look at Ebot, floating gracefully like a tethered kite against the glistening, icy stream of gas and dust behind the comet. It looked like a small person on a Jet Ski was motoring across the sky.

  “Bye, Ebo— er, I mean, Dad,” said Annie sadly. Then, whispering, “I hope you get kidnapped soon.”

  “Bye … er, Eric,” said George.

  “Rats.” Annie’s finger hovered over the keyboard, ready to give the command to shut down the portal. “I was so sure this was going to work; I was so sure that I AM would be monitoring all space communication channels and that Dad showing up in space would cause him to swoop down on him like the robots did last time.”

  “Perhaps we should have gone to the Moon,” said George. “Maybe that’s the only place I AM hangs out.”

  “But how could we?” asked Annie. “We can only get Cosmos to take us to a place where there’s stuff for my chemistry project—and that’s not the place where we needed to be.”

  HOW LONG IS A “DAY” ON EARTH?

  Why is a day in winter shorter than a day in summer?

  It’s because the Earth tilts on its axis as it orbits around the Sun. If the Earth stayed upright throughout its whole orbit, day and night would be exactly the same length on all days of the year. But as the Earth orbits, it is at an angle of 23.5 degrees, and this means that at one point in its orbit, the North Pole and the region we call the Arctic Circle is angled so far away from the Sun that it receives no daylight at all.