Showing papers by "Peter Wegner published in 2012"

Computational Completeness of Interaction Machines and Turing Machines.

Abstract: In the paper we prove in a new and simple way that Interaction machines are more powerful than Turing machines. To do that we extend the definition of Interaction machines to multiple interactive components, where each component may perform simple computation. The emerging expressiveness is due to the power of interaction and allows to accept languages not accepted by Turing machines. The main result that Interaction machines can accept arbitrary languages over a given alphabet sheds a new light to the power of interaction. Despite of that we do not claim that Interaction machines are complete. We claim that a complete theory of computer science cannot exist and especially, Turing machines or Interaction machines cannot be a complete model of computation. However complete models of computation may and should be approximated indefinitely and our contribution presents one of such attempts.

Introduction to What is Computation

Abstract: What is computation? This has always been the most fundamental question of our field. In the 1930s, as the field was starting, the answer was that computation was the action of people who operated calculator machines. By the late 1940s, the answer was that computation was steps carried out by automated computers to produce definite outputs. That definition did very well: it remained the standard for nearly fifty years. But it is now being challenged. People in many fields have accepted that computational thinking is a way of approaching science and engineering. The Internet is full of servers that provide nonstop computation endlessly. Researchers in biology and physics have claimed the discovery of natural computational processes that have nothing to do with computers. How must our definition evolve to answer the challenges of brains computing, algorithms never terminating by design, computation as a natural occurrence, and computation without computers? All these definitions frame computation as the actions of an agent carrying out computational steps. New definitions will focus on new agents: their matches to real systems, their explanatory and predictive powers, and their ability to support new designs. There have been some real surprises about what can be a computational agent and more lie ahead. To get some answers, we invited leading thinkers in computing to tell us what they see. This symposium is their forum.

The Evolution of Computation

Abstract: Computer science emerged as a discipline about 70 years ago, some 2,000 years after the Greeks created mathematics, physics and philosophy. However, the questions “What is Mathematics?” and “What is Physics?” remain unanswered, and it is not surprising that the specification of computation likewise remains unresolved, in spite of the increasing centrality of the computing discipline.