Unconventional Computer Programming

Abstract. Classical computing has well-established formalisms for specifying, refining, composing, proving, and otherwise reasoning about computations. These formalisms have matured over the past 70 years or so. Unconventional Computing includes the use novel kinds of sub-strates – from black holes and quantum effects, through to chem-icals, biomolecules, even slime moulds – to perform computations that do not conform to the classical model. Although many of these substrates can be “tortured ” to perform classical computation, this is not how they “naturally ” compute. Our ability to exploit unconventional computing is partly ham-pered by a lack of corresponding programming formalisms: we need models for building, composing, and reasoning about programs that execute in these substrates. What might, say, a slime mould program-ming language look like? Here I outline some of the issues and properties of these uncon-ventional substrates that need to be addressed to find “natural ” ap-proaches to programming them. Important concepts include embod-ied real values, processes and dynamical systems, generative systems and their meta-dynamics, and embodied self-reference.