The forecast itself becomes more interesting and more understandable if we look into the meanings of the terms that forecasters use. Some parts of the weather forecast seem easy enough to understand—for example, the predicted high and low temperatures. But weather terms such as "high-pressure system," "occluded front," or "temperature-humidity index" sound more complicated. The meanings of these terms become clear, however, once you know something about the major factors that produce the weather and how these factors influence one another.
Atoms: the building blocks of life and the universe. We're all made of these microscopic bits of matter, but how many does it take to make a complete human being? And exactly what kinds of atoms do we have inside us?
Nuclear materials get used in many forms of nuclear medicine -- everything from PET scans to chemotherapy uses them. Learn how nuclear medicine works.