Science is not just a list of facts in a textbook. It is a way of asking questions and testing the answers. A scientist first observes something carefully and writes down every observation. Then he or she devises a theory to explain what is happening. However, a theory remains only an idea until there is enough evidence to support it. That is why researchers repeat their experiments in the laboratory many times. If the results stay the same, they may finally have proof. Even a famous chemist or physicist can make mistakes, so good scientific work always leaves room for new questions.

Last spring, two junior high school students in Tainan won an award at a national science fair. Their invention was a simple water filter made from sand, small stones, and old plastic bottles. The idea came to them when they noticed dirty water in a ditch near their school. At first, their experimental filter did not work well, and the water still looked brown. Instead of giving up, they asked their chemistry teacher for advice and changed the design five times. Finally, the water came out clear. "Failing was tough," one of them said, "but it taught us more than any textbook."