In physics, phenomenology is a method by which natural phenomena can be observed based upon theoretical ideas. In other words, suppose we have a mathematical theory of some kind that says that there should be very small particles within the nucleus of an atom that somehow keep the nucleus from falling apart. We can use that theory to find a way to test whether or not this is actually true. This is a different way of approaching science than the scientific method, in which we have a question that we want to answer, we form a hypothesis, we test the hypothesis, and then we interpret the data to get our answer. Phenomenology in physics is useful because the world of physics, especially quantum physics, is very small or deals with phenomena that occur very far away in space and the like. It is very difficult under those circumstances to simply know all the questions to ask, to test a hypothesis based on a question, and then to collect data to support that. Besides, in physics, when dealing with the subatomic, our efforts to observe or measure what is going will actually influence the outcome of what we can observe. This must somehow be taken into consideration, and in phenomenology, it is. Phenomenology is, in short, a sort of way to understand the whole truth about natural or physical phenomena in their entire context.