We describe a possible physical device that computes a function that cannot be computed by a Turing machine. The device is physical in the sense that it is compatible with General Relativity. We discuss some objections, focusing on those which deny that the device is either a computer or computes a function that is not Turing computable. Finally, we argue that the existence of the device does not refute the Church–Turing thesis, but nevertheless may be a counterexample to Gandy’s thesis.

this article we describe our view of the area and relate it to the problem solving processes in science and engineering. Realities

One of the major issues of the “Tensions of Europe ” (ToE) network concerns the influence of technology on the process of economic, social and political integration in 20th century Europe. This is clearly reflected in the three main lines of investigation followed across the different themes: the linking of infrastructures, the circulation of artefacts and services, and

This course provides an introduction to the capabilities, applications, and limitations of the computer as a problem solving tool. The course provides the student with an