The Science of Energy

The search for an understanding of energy, the stuff that drives the Universe, has fascinated people for centuries. Have you ever felt full of energy? When you do you feel that you can make all sorts of things happen. You can work hard if you want to, or you can play for hours. If this is what you mean by energy then you are very close to what a scientist means by it. The word itself comes from the Greek word energeia , which means “in work.” Energy can make things happen. Energy makes things warmer, energy can move things, energy can make things brighter and energy can help living things grow. The more energy there is the more it can do, just as you can do more when you have lots of energy. If a scientist describes an object as “energetic,” he or she means that the object can do things. For instance, if you see a ball on the ground it should be pretty obvious that it doesn’t have much energy. It isn’t doing anything just lying there. However, if you give it some energy by kicking it, it will be able to do things, such as breaking a window if you’re careless about the direction you kick it in! The ball didn’t suddenly get its energy from nowhere. You had to give it the energy it needed to leave the ground and move through the air. DI FFERENT FORMS OF ENERGY As we shall see, scientists believe that the amount of energy in the Universe always stays the same. It is impossible to make new energy. This means that if you want to make something happen you have to transfer energy from somewhere else. When you kick a ball, you use chemical energy in your muscles to move your leg and give the ball movement energy . The chemical energy in your muscles comes from chemical energy in your food. 4. Chapter MAKING IT WORK