Scientific inquiry depends on systematic examination of a phenomenon.
Once the observations have been made, the observer suggests a reasonable explanation for them, then tests this explanation. The explanation is called the hypothesis, and the tests are experiments. An explanation is accepted until it is proven false. To prove an hypothesis to be true, one must test and validate the hypothesis for every possibility, virtually impossible in terms of time and money. If an hypothesis is proven false or inaccurate by experiments, it is modified or discarded.