 Thus one sees that the role of the Turing machine for computer science should be situated rather on the theoretical level: the universal machine is today by many still considered as the model for the modern computer while its ability to mimic machines through its manipulation of programs-as-data is one of the basic principles of modern computing. Moreover, its robustness and naturalness as a model of computability have made it the main model to challenge if one is attacking versions of the so-called (physical) Church-Turing thesis.