Science (from Latin scientia, meaning "knowledge") is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe. Contemporary science is typically subdivided into the natural sciences which study the material world, the social sciences which study people and societies, and the formal sciences like mathematics. There is an ongoing debate on whether Mathematics is a Formal Science or not - I for one do not believe that Mathematics is and should be treated at the same level of Science (it's not like the mathematics in another universe is going to change although it might describe the other universe differently). Furthermore, Jim Gray (Turing Award Winner and a great mentor for a short time back in 1996 on Digital me) has also proposed in a new Science - the Science of Data.
The ontology is outlined as follows: