ABSTRACT
A rocket stands on the launching pad, its engines ignite, and the rocket lifts, accelerates, leaves the Earth’s atmosphere and takes its satellite into orbit. Why did the rocket need engines? Why don’t things just drift effortlessly into space? Why did the rocket burn up in the atmosphere when it fell back to Earth? Why did the satellite circle the Earth repeatedly, even though it had no engines? When the astronauts looked back at the Earth, they could see a large, tight swirl of cloud. Under the storm, high waves make small ships bob up and down, and lightning flashes from cloud to cloud and cloud to masthead. Why don’t ocean waves sweep ships along with them and throw them on to some beach hundreds of miles away? Why are there lightning flashes? Why did lightning strike the masthead and not the deck? While this is happening, less dramatic events occur in every home. Someone switches on a lamp in the kitchen. It flashes then goes out. She feels in the drawer for a torch and goes to the fuse-box. Having replaced the fuse, she tries the switch again and the lamp works. She makes some sandwiches and begins to wrap them. The plastic stretches but not enough, so she puts the sandwiches in to a bag and holds the pack together with an elastic band. Why did the lamp go out? Why does a torch give off light? Why was the light confined to a beam? Why did the plastic film and the elastic band behave differently? All these events, spectacular and otherwise, involve physical processes. Why events like these happen as they do-or happen at all-is what this aspect of science is about.
