For 300 years mathematical equations were the dominant method used to make models of things. In just the last decade or so, there’s been a kind of silent revolution in modeling, and new models of almost any concept or system—regardless of whether it is physical, engineering, social, biological—have started to be based on computation (and effectively, programs) rather than mathematical equations. It’s quite a paradigm shift, which is why I called my big book on the subject A New Kind of Science.