The two legs of science are more accurately referred to as theory and observation. Experimentation is one way to gather observations, but it is not the only on

The two legs of science are more accurately referred to as theory and observation. Experimentation is one way to gather observations, but it is not the only one. Astronomy involves a lot of observation of stars, which are some distance outside of the laboratory and definitely not in an experimenter-controlled environment. I would classify numerical/computational models, along with mathematical and philosophical models, under "theory". Number-crunching and heavy data analysis is a way to categorize and present observations. None of these deserve to be treated as new and separate legs of science; they are merely subsets of the existing legs of theory and observation.