The Scientific Process
Scientific observation, like that conducted in astronomy, does not differ fundamentally from any other kind of observation. One thing we ask is that it is repeatable. Scientists tend to mistrust single observations on unusual phenomena (such as UFO sightings). Also, like detectives reconstructing an accident, they tend to mistrust witnesses untrained in proper observation or emotionally involved in what is being described, or both.
Books have been written about what Science really is. Clearly, it has to do with knowledge, and it also has to do with skills. Scientists use their special knowledge and skills to find out about how things and forces work together to make up the world around us. "The world around us" includes everything we can measure or at least perceive, from invisible and elusive particles such as neutrinos (which weigh practically nothing) to clusters of galaxies so large it takes millions of years for light to go from one end to the other. "The world around us" includes Life and its history, the things that make our planet so special and wonderful. And it includes the flow of goods and money, and the way decisions are made by the various levels of government – that is, economics and political science. The natural sciences differ from the social sciences in that much of natural science deal with phenomena that can be replicated, in principle, while this is practically never the case for the social sciences.
Science is what scientists actually do, not what philosophers and sociologists say they do, or should do, or could do. Nor is Science is the same as engineering, which deals with making things for human use or with fixing things - although the most inventive engineers are invariably good scientists and most scientists rely on engineers because they need advanced instruments and computers for their work. Science is not the knowledge codified in an encyclopedia, although scientists know a lot of facts.
Science is a procedure for converting observations into "understanding", or more precisely into general rules about what will be observed given certain conditions. Such conditions can be brought about in an experiment. For example, take a pot of water with a tight lid on it and heat it. The lid will be lifted and vapor will escape to make steam. Or freeze a can of chicken soup: it will burst. Finding out why this is so, and predicting when it will occur, is a matter of physical science. The same principles governing the steam-producing pot are found again when studying clouds and storms. The principles governing bursting-upon-freezing explain why ice floats.
Thus, by extracting rules from some observations, we can "explain" or "predict" seemingly unrelated different observations. Making up sets of rules is called "generating hypotheses." Scientists love to do this because if a hypothesis survives a lot of challenges it becomes accepted theory, and if it is important, the scientist who invented it looks sharp. Scientists spend much of their time testing hypotheses, that is, they try to shoot down sets of rules, preferably rules that have been invented by others. Some theories are fundamental to a whole network of hypotheses.