Leonie writes from somewhere in the world: "Why do we need and use energy? Where did all the energy come from? When was energy brought to these worldly lives of ours? Who was the first person to find out about energy and its different types of energy? How do we use energy? Why do we need and use energy?"

Answer: Good questions! You obviously have a very inquisitive mind. While I am generally credited with being a very clever guy, I must admit that I don't have the answers to all of those questions. I'll bet the first person to find out about energy was a cave man or woman who noticed that fire, probably started by lightening, was nice and warm. Later someone figured out how to start a fire without lightening and found that some things burned easier than others. To find some real answers about energy, I suggest you visit a few online resources that cover the topic of energy. A good starting place is the Alliant Energy Kids website and its page about Energy Basics. Other good sources I have listed previously include the California Energy Commission website that presents The Energy Story, and the online Coal Research Tutorial from the Argonne National Laboratory.