George and the Ship of Time

by Lucy Hawking

  “Get out of here!” he yelled. And the Queen of Other Side’s avatar abruptly disappeared.

  So busy were all the grown-ups, arguing ferociously among themselves about what should happen next, that they didn’t notice the lift doors opening again. A whole stream of new arrivals burst out into the room.

  As the adults slowly realized that they had been invaded, their furious voices died away. One small figure detached itself from the group and stepped forward.

  “I have,” she said, looking around with perfect composure, “a question.”

  Chapter Twenty-Four

  “Hero!” Nimu tried to step forward but Annie, her sister, held her back.

  “No, Nimu,” she said. “Let her speak!”

  “I have a question!” said Hero again. She seemed to have grown since George last saw her. She appeared perfectly at ease and very confident.

  Dump, on the other hand, looked the opposite. “I pay you,” he snarled to his advisers, “to keep children out of here! Where is that pesky Child Hunter?”

  “You sent him away!” one of the courtiers reminded him. “With the other boy.”

  “Get him back,” said Dump. “This is totally his fault! Why are these kids here in Edenopolis? I want an answer!”

  “So do I!” said Hero. “Why did you lie to us kids? Why couldn’t we have a proper education and learn about the world as it really is?”

  Dump just gaped at her. He looked around blindly, motioning for one of his advisers to reply. But they all backed away from him.

  Instead, Annie stepped forward. She smiled at Hero. “Hello, Hero,” she said. “I’m your aunt Annie!”

  “Cool!” said Hero, obviously impressed by this glamorous but tough-looking new person. “What’s an aunt?”

  “Where did you come from with all these kids?”

  Hero looked around at the group behind her. “I freed them,” she said simply. “I went to Wonder Academy because I had to find out what had happened to the kids from the Bubble!”

  “What was Wonder Academy like?” said George, agog. He couldn’t believe she had done this all by herself.

  “It was weird and horrible! None of the kids there were learning anything.” She looked accusingly at Nimu. “They were having their brainpower sucked out of them to support Trellis Dump and make him smarter! And you wanted me to go there!”

  “I didn’t!” pleaded Nimu. “I didn’t want you to go there at all. I’m so sorry!”

  “How did you get them out?” asked Annie.

  “I had some help,” admitted Hero. “But I mostly did it on my own.”

  “Who from?” asked Annie, unable to keep quiet. “Who has been helping you?”

  “My robot,” said Hero. “The one my guardian got from the trash camps. I thought he was useless but he’s actually been quite cool.” She flashed the Digitizer. “I’ve been speaking to him through this! He helped me when I didn’t know what to do.”

  Annie looked over at Cosmos, who carried on gazing out the window. “And you got all these kids out of Wonder Academy and brought them here?” she said.

  “Well,” said Hero, “it was after a lady called Matushka told us the truth about Wonder. She’d been there, you see. Then I knew I had to go and get my friends out. So I did.”

  “But . . .” said Nimu. “How?”

  “You all,” said Hero, glaring angrily at Nimu and the other adults, “think us kids can just be bought off with loads of mindless stuff to stop us pestering you. And all the while you were trying to use our brainpower to make Eden work! And you made us think that we owed you trillions of Dumplings and would have to work really hard all our lives to pay you back! Pay you back for making us work! When you had ruined the world we live in!”

  Every adult in the room had fallen silent.

  “It’s really all thanks to George,” said Hero, smiling and showing a dimple. “He was the first person who actually bothered to tell me that things were not the way I thought they were. I didn’t believe him at first. I thought he was crazy. But he wasn’t. He was trying to help me.”

  “I was,” said George.

  “And George got me out of that Bubble.” Hero said the word with disgust. “Which was really brave of him. It was brave of me too, except I didn’t know I was being brave so it doesn’t count.”

  “You fought a tiger,” George reminded her.

  “And if George hadn’t rescued me,” continued Hero, “I might have been put to work in Wonder Academy as a brain slave for the Eden regime, just like all my friends.” She waved her hand to indicate a group of very irate-looking young people, now arranging themselves around the room.

  To George’s great relief, he saw Atticus at the back. Beside him stood a tall figure with long silver hair. George realized that it was Matushka, standing proudly with her son. She must have managed to persuade the people of the colony to join the Resistance after all, and then brought them to Edenopolis to help overthrow Dump.

  “You,” said Hero to Nimu, “have some explaining to do.”

  Nimu looked utterly crestfallen.

  “H-Hero . . .” she stuttered.

  George stepped forward. “Hero,” he said. “Your mom”—he pointed to Nimu—“is actually a bit of a hero herself. It’s not quite the way it looks. She protected you, you know, by keeping you in the Bubble, by giving you Empy, by asking me to take you to na-h Alba.”

  Hero blinked; clearly this was something she hadn’t really thought about before. Nimu shot George a grateful smile. But Hero was still on a roll. She couldn’t think about herself right now, not while there was so much else to consider. She stood taller.

  “We’ve got way more to do—there are kids all over Eden who need our help!” she said loudly to the crowd around her. “And”—now she turned accusingly to Dump—“you still haven’t answered my question!”

  “Your question.” Dump imitated her in a particularly nasty high voice. “Your question! I am President Dump, you silly little girl! I am ruler of Eden, and now of Other Side as well. I rule the world and everything in it. And you just ran up another two trillion in Dumpling debt. Enjoy paying it back, loser!”

  “I don’t think so.” George had just had a whispered conversation with Cosmos and had some new updates for the leader of Eden. “You are not President of Eden. Not anymore. You’ve just been deposed.”

  “Liar!” cried Dump. “I can’t be deposed! I passed a law saying I would be President of Eden forever more! No matter which way people voted!”

  “That means nothing now,” George continued. “You relied on the brainpower you took from these kids to make yourself clever enough to give the orders, and on the intelligent machines you used to carry them out. But you’ve lost them both. The kids are escaping and the machines have finally turned on you. I bet not one bot in Eden, from a lawn-mowing robot to the one that launches nuclear missiles, will obey you now. And, without your stolen brainpower, you won’t be able to outwit them. You are finished.”

  “Loser,” said Hero, who had clearly just picked up that word and liked it.

  Annie smiled and winked. “She’s quite right,” she said. She turned to the rest of the room. “Who here wants the reign of Dump to continue?” she called.

  Not a single person or robot spoke up.

  Annie turned back to Dump, who stood pale and crumpled in the center of the room.

  “Look,” he said. “There’s no need to be hasty . . . we can . . .”

  Nimu said something into Annie’s ear. She nodded. “Good idea!” She motioned to the robots, who swiftly grabbed Dump and dragged him out of the room.

  “Where are they taking him?” asked George as Dump disappeared, struggling against his robot escort.

  “Until we decide what to do with him, we’re going to put him in a cell with some of his most enthusiastic supporters!” said Nimu. “I can’t think of a punishment he’ll like less.”

  “But who is going to be the leader now?” asked one of the kids behind Her
o. Everyone automatically turned toward Annie. She had the air of a leader—an experienced warrior who could navigate the world away from the long-erupting state of crisis in which everyone had lived for far too long.

  “Me?” she said. “Don’t you think I’m a bit old?”

  “Well, you’re the same age as me,” said George. “In a way.”

  “But I’m not,” said Annie. “It’s time for me to hand things over. I don’t want to rule the world. I just want it to be a better place. Anyway, I think you’ve had quite enough of old people telling you what to do.”

  “Annie,” said George. “What do you mean? What are we going to do now?”

  “We?” said Annie. “I think you mean you—you and Hero. And Atticus. And all the kids. You can’t go back to the past, George. But your ship of time has brought you to now. And you can go forward into the future. This is your world now, George, yours and Hero’s. And it will be whatever you decide to make of it.”

  Time Travel and the Mystery of the Moving Clocks

  by Professor Peter McOwan

  Ticktock is the familiar sound of a clock and time passing. We all know about time—or at least we think we do! When we are together in a room, my clock shows the same time as your clock, my ticktock is the same as yours, and time passes at a steady beat. If you went on vacation to a distant country, your ticktock and mine would be the same, even if our clocks showed a different time of day.

  But time is an interesting thing because it can pass at different rates if you start to move very fast. When you measure the ticktock on a speeding spaceship like George’s, it looks slower than the ticktock of a clock back on Earth. Scientists call this strange effect time dilation, and it happens because light has a speed limit.

  To understand time dilation we need first to understand something about light.

  Light shining through the vacuum of space has a fixed speed. Scientists call this speed c, and it’s around 186,000 miles per second. Though light can slow down when it passes through thick stuff like glass, when it’s in free space its speed is c, and that speed, c, happens in whatever direction you shine the light in.

  It’s this fixed speed that gives us time dilation: time on a super-fast moving spaceship passes more slowly than time on the Earth. This is the science behind how George is able to travel one way into the future. He travels so fast that only days pass for him, while on Earth years go by.

  This all seems crazy, but that’s because you can never in reality move fast enough to notice. However, if you could move at speeds near the speed of light, then your ticktock as seen from Earth would become more of a tiiiiiicktoooooock. To get a feel for why this is, we need a light clock in a see-through spaceship.

  Our spaceship light clock is simple—a bulb on one side of the spaceship and a mirror on the other, with the super-powered engines at the back. When the spaceship is stationary, the bulb switches on, and the light from it shoots over the distance inside the ship to the mirror and is reflected back. Tick is the time taken to go over to the mirror, and tock is the time taken to come back from the mirror.

  If we had a mirror 186,000 miles away, then light from a (very bright) bulb would take one second to get to the mirror and another one second to come back, because light travels at c, so that first flash is going to travel 186,000 miles in one second, and take one second to come back.

  Back on the stationary spaceship, our light clock will happily flash its ticktock at the same rate whenever we look at it, and we can use it to set all our other clocks on Earth to the same ticktock.

  But we now launch our see-through spaceship so that it’s moving very, very quickly, and watch it from Earth. The first flash from the bulb shoots out toward the mirror but, as we look at it from being stationary on Earth, in the time the light takes to cross over to where the mirror would normally be, the mirror has moved. The distance the mirror moves will depend on how fast the spaceship is traveling; if it’s very fast, then the light takes a longer sloped path to hit the mirror. Because the light traveled farther and light speed, c, doesn’t change, from our viewpoint this could only mean that the time it took to get to the shifted mirror was longer. What was tick on our stationary light clock now becomes tiiick.

  On the reflection of the light, the same thing happens: the light coming from the mirror has to cover a longer distance to get back to where it started, so our tock is now tooock. This means that when we look from Earth, a moving clock runs slower than a stationary one and it seems that less time has passed on the moving spaceship. For example, when the spaceship’s slow-running clock has only reached one o’clock, while it’s now five o’clock on Earth, that would mean the spaceship is four hours into the Earth’s future.

  You can also think about this time dilation with some simple letter shapes. When the clock is stationary, the flashes travel back and forth like two letter I’s, as the mirror and bulb are straight across from each other. The first I is the journey to the mirror, the second I is the journey from the mirror. But when our spaceship moves, the path of the light seen from the Earth is more like a V. The light now has to travel a longer distance at an angle to bounce off the shifted mirror at the bottom of the V, and again cover a longer distance to return to the start. The difference between the II and V distance means that, from Earth, it takes longer to have a pulse reflected back when the clock is moving, so the moving clock is slower.

  That’s the basic idea behind time dilation, and it’s a prediction of the Theory of Relativity, which was one of scientist Albert Einstein’s great breakthroughs (although, of course, the details of his theory are a bit more complicated). Though Earth sees my clock as running slow, if I’m on the spaceship, then from my viewpoint I’m stationary and it’s the Earth that is moving away from me, so I see the Earth clock running slower, not mine. Both Earth and spaceship points of view are right, so why is it only on the spaceship that time travels into the future?

  If you look closely at the mathematics, it turns out that changing speed can also cause time dilation. Since only the spaceship has to change speed and direction to turn around to get back to Earth, the conditions on the spaceship’s flight are different from those on Earth. It’s the time dilation from the spaceship’s super-fast speeds and midcourse about-face that causes the time difference that shoots the returning spaceship one way into Earth’s future.

  We can’t yet fly spaceships at speeds anywhere near light speed, but we have some interesting experiments that show that Einstein and his time-dilation idea was correct. In an accelerator—like the one at CERN in Switzerland—particles are pushed to move at speeds near the speed of light, and usefully many have their own sort of clocks on board. A particle half-life is related to the time it takes for the particle to disintegrate into other smaller sub-particles. We can measure this half-life in the lab when the particle is stationary, and we can also measure it when the particle is moving. It turns out that when the particles move, the “half-life” clock does run slower than when they’re stationary, and by an amount exactly predicted by Einstein.

  Climate Change—and What We Can Do About It

  by Lord Nicholas Stern

  What does climate change mean?

  The weather can change every day; one day it’s rainy and cold, another day sunny and hot. And some months and years can be hotter or rainier than others. But when we take the weather over a long period, say thirty years, we can calculate averages of temperature and rainfall and other measures of weather. We call these averages the climate.

  During one human lifetime, in any one particular place on Earth, the climate tends to stay more or less the same. But it is different around the world. For instance, places close to the Equator tend to be warmer than places closer to the poles of the Earth. Rain forests have climates that are wetter than deserts.

  Over the past century, however, scientists have made detailed records of the climate in many different areas of the Earth, and have discovered that most places have become warmer on average. We
call this global warming, and it is having many different effects. For instance, it means that ice has started to melt in many places—such as in mountain glaciers, and in ice sheets on the land and sea around the North and South Poles. The melting land ice is then entering the world’s oceans and causing our sea levels to rise. Some places are becoming wetter and some places are becoming drier. All these impacts together are known as climate change.

  Scientists have concluded that the main reason for this change in the Earth’s climate is us: human activities. Although the Sun warms the Earth, our atmosphere makes the surface of our planet about eighty-five degrees Fahrenheit warmer than it would be if we didn’t have this atmosphere. It works like this. When energy from the Sun reaches the Earth’s surface, it raises its temperature. Heat from the Earth’s surface then escapes into space, but some of it is trapped by the gases in the atmosphere—gases such as water vapor and carbon dioxide. This is known as the greenhouse effect, as the principle is very similar to how greenhouses are heated to help grow tender plants in cold areas.

  Carbon dioxide is a very important factor here. Since the eighteenth century, the amount of carbon dioxide in the atmosphere has started to increase, causing more heat to be trapped by the atmosphere, warming the Earth. Most of this carbon dioxide has come from burning fossil fuels, such as coal, oil, and natural gas for heating, for use in industries such as steel and cement, to generate electricity, and to provide power for cars and trains. Other greenhouse gases include methane, which is produced, for instance, when garbage rots in landfill sites or from the digestive systems of cattle. Carbon dioxide is also released when we cut down trees and they are buried or they rot.