December 16, 2007

Root Cause

Hello Callum. For Christmas this year I've given you a rocket that runs on water. The energy from the batteries breaks the water into two ingredients: hydrogen and oxygen. Oxygen is also in the air; people and animals need to breath oxygen so they can live. Hydrogen is the simplest ingredient of all. When you set light to hydrogen it mixes with the oxygen in the air making water again. The hydrogen combines with the oxygen really quickly, releasing the energy that came from the batteries. When that happens, it causes an explosion. The explosion pushes the rocket up into the air. It's the energy from the batteries that makes the rocket shoot up.

Hydrogen is good for holding energy because when you release the energy it makes only water, which doesn't hurt the environment. But hydrogen takes up a lot of space, and it takes a lot of effort to squash it down into small containers. If it accidentally catches light, hydrogen explodes, so it's also hard to make it safe.

The batteries have ingredients in them that are mixing very slowly. As they mix, they release energy. The factories that make batteries use machines that take the ingredients out of the dirt in the ground. The machines are plugged into the wall, like your microwave is. They use energy from the plug socket to take the ingredients out of dirt that they use to make batteries. So the energy from the plug socket makes the rocket shoot up.

The energy in the plug sockets comes from the power stations along metal wires. Sometimes when you drive along the motorway you can see really big towers with wires between them; those are the wires that carry the energy from the power stations to the plug sockets. So really, the energy from the power stations makes the rocket shoot up.

The power stations have big fireplaces where they burn coal. They use the heat-energy from the fires to boil water. The heat-energy is changed into pushing-energy in the steam. So they use the steam to spin fans. And the fans are connected to machines that can put the spinning-energy into the wires. So the energy from the coal makes the rocket shoot up.

The coal is dug out of the ground. It was put into the ground a long time ago, before the dinosaurs. When it was put in the ground, it was wood. When wood gets crushed for a long time, it becomes coal. The wood was put into the ground because trees fell down and then dirt collected on top of the trees. Over a long, long time, a lot of dirt collected; enough dirt to be so heavy that it crushed the wood into coal. The energy from those trees makes the rocket shoot up.

Before the dinosaurs, the world was really hot. It was hot because the air was different than it is now. The air had more of an ingredient called carbon in it. The carbon makes the air work like the glass in a window; the sunlight can come in but the heat can't get out so easily. Carbon is the main food of trees; they breathe it in and they grow their trunks and branches out of it. Trees use the energy of the sun to breathe in the carbon. Trees also breathe out oxygen, which it what people and animals breathe in. When the coal, which is made of the trees, is burned in the power stations, the heat energy from the sun is released, and so is the carbon. So the carbon goes back into the air. The power stations have been burning coal since before granny's granny was born. All that time, they've been putting the carbon back into the air. So the world has been heating up again. It might not be good for people if the earth keeps heating up because it might cause changes that make it harder to live. So the energy from the sun makes the rocket shoot up.

The sun is a star that's much closer than any of the other stars. The sun is made mostly of hydrogen, the ingredient that explodes when you light it, like a fire. That explosion pushes the rocket up. The sun is burning so hot that it burns differently from a normal fire. In a normal fire, the ingredients are mixed together and some energy is released. In the sun, it's so hot, that the ingredients are changed into different ingredients. When that happens, a lot more energy is released than in a normal fire. The sun is changing hydrogen into lot of other ingredients, including oxygen and carbon. The sun is so hot that it if you walked towards it, you would melt like an ice cream when you were still a very long way away. You'd still be so far away that if you could keep walking, you would still not reach it by the time you were as old as mummy. So the energy released when the sun changes hydrogen into other ingredients is what makes the rocket shoot up.

From where did the hydrogen-energy come? No one is certain. Some people say there was a big explosion a very, very long time ago. In that big explosion, even smaller ingredients were changed into hydrogen. But no one knows where the big explosion came from. Maybe it was little boy pushing a button in his garden to make his toy rocket shoot up into the air.

The sun is so hot that it accidentally makes some ingredients that are really heavy and are easy to change back into lighter ingredients. The earth is the left-over ingredients from a star that existed a very long time ago. The earth contains some of the heavy ingredients that are easier to change back into lighter ingredients. People collect the heavy ingredients and release a lot of energy by changing them into lighter ingredients. That's how some of the power stations produce energy, rather than burning coal. Even though doing that doesn't put more carbon into the air, which would make the earth warmer, it does produce ingredients that can hurt humans and are very dangerous.

There's hydrogen in the sun and there's hydrogen in your rocket. The sun burns it really hot and turns it into oxygen. Your rocket burns it like a fire — it mixes with oxygen in the air, making water. The trees that lived before the dinosaurs used the heat energy from the sun to breathe in carbon and breathe out oxygen. The fires in the power stations give out heat energy by burning coal; they breathe in oxygen and breathe out carbon.

The rocket uses energy to shoot up. Other things that use energy are moving cars, heating houses, and printing books. People like doing these things so we're working out how to get energy without hurting the earth; because by hurting the earth we hurt ourselves.

Wind has pushing-energy, rain has falling-energy, sunlight has heating-energy, and waves have wobbling-energy. All of this energy comes from the sun. The wind, rain, and waves can push fans like the steam in a power station. There are machines that can put the sunlight into wires. Sunlight can also be used to grow wood and plants that can be burned to make heat-energy. The sea goes up and down as the moon moves, so the sea has lifting-energy. The middle of the earth is hot, so it has heat-energy. The middle of the earth is still hot, and the moon is still spinning around the earth, from when the earth was made from a dying star. People are getting energy in the ways I just mentioned more and more.

I wonder if we could use the heat-energy from the middle of the earth to cool it down enough so that the heating caused by the carbon in the air doesn't matter any more. I think it could be dangerous to try to manipulate something as complex as the earth.

Even if we tried to get all our energy from the sun, there's not enough energy coming from the sun for all the people on the earth. The movement of the moon and the heat inside the earth is not enough either. People are trying to solve that problem by making tiny suns on earth. They're so hot that they can't be kept inside boxes made of wood, metal, or bricks because the boxes would melt. So they have to make boxes out of invisible forces, the same forces that make magnets stick together or balloons stick to the ceiling. No one really knows what those forces are but they know how to make them do things. To make a box which is strong enough to hold the sun uses lots of energy and it's very tricky.

What about if we made extra little suns in space around the earth? We could put mirrors between the suns and the earth, to protect the earth from the heat. We could have wires running down from space, carrying the energy to us.

All that energy coming down to earth would still have to go somewhere. Otherwise the earth would heat up. I wonder if it we could spit heat back into space, to keep the earth cooler. But you can't spit heat into space, because there's nothing to heat, that's why it's called space. Perhaps we could send the heat to one of the other planets that's going around the sun. The other planet would heat up after a while though, and then there would have nowhere left to send energy.

We could try to keep the same number of people on the earth, or even have less. We could do that by limiting the number of babies we have. Or maybe we should send people into space to live on other planets. It's also good for all the people to use less energy but it doesn't stop the problem of there being more and more people on the earth.

Me, and the people my age, are trying to solve these problems. You and the people your age can help too. As you all get older, you'll be able to help even more.

I know all of this because I'm an engineer. But I realized that even if people knew what to do, they wouldn't do it unless they really wanted to. To make a big change, a lot of people have to do things differently. So the problem is really inside the people. That's why I'm becoming a doctor of psychology. Psychology is about what people do and why they do it. I imagine that when the problems inside people are solved, the problems with the earth will be fixed very easily.

Didn't we figure out that the big explosion a very long time ago made the rocket shoot up? Maybe you made the rocket shoot up when you pushed the launch button. Did Callum make the rocket shoot up? What's the difference between Callum and the big explosion that started everything? How are they the same?