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BEFORE YOU BEGIN...

Before you begin the experiments in this book, take a minute to think about energy. What is it? Where does it come from? What is it used for? And why are people all over the world so concerned about the “energy crisis”?      In simple terms, energy is the ability to do work. There are many forms of energy: radiant (which includes light), thermal, chemical, mechanical, electrical, nuclear, and gravitational. Energy itself is never consumed (that’s the First Law of Thermodynamics); it’s only changed from one of these forms to another.      The problem is, whenever it changes form, some of it is “lost.” It changes into unuseable heat, which dissipates and gradually warms up the earth’s atmosphere (and that’s the Second Law).      As an example, look at all the changes energy could undergo in order to light your living room tonight (see page 5). Conversions Mean Lost Energy      The more conversions there are between the primary source of energy and its final use, the greater the waste. Some machines and processes not only use more energy, they also require more conversions before the energy is finally used. In 1979, the United States wasted more energy than it had both used and wasted in 1960. This is one reason behind the energy crisis.      Another reason is our dependence on fossil fuels, especially oil and natural gas, as our primary supply of energy. These resources were created millions of years ago. Unlike sunlight, wind, water, or living plants, they cannot be replaced. You can grow another tree, but once a barrel of oil is gone, it’s gone forever.