Читать книгу Physics I For Dummies - Steven Holzner - Страница 13

You can observe plenty going on around you in your complex world. Leaves are waving, the sun is shining, light bulbs are glowing, cars are moving, computer printers are printing, people are walking and riding bikes, streams are flowing, and so on. When you stop to examine these actions, your natural curiosity gives rise to endless questions such as these

 Why do I slip when I try to climb that snowbank?

 How distant are other stars, and how long would it take to get there?

 How does an airplane wing work?

 How can a thermos flask keep hot things warm and keep cold things cool?

 Why does an enormous cruise ship float when a paper clip sinks?

 Why does water roll around when it boils?

Any law of physics comes from very close observation of the world, and any theory that a physicist comes up with has to stand up to experimental measurements. Physics goes beyond qualitative statements about physical things — “If I push the child on the swing harder, then she swings higher,” for example. With the laws of physics, you can predict precisely how high the child will swing.