The All-Or-Nothing Nature of the Church-Turing Thesis

Stefan Wolf de l’Université de Lugano

Landauer's principle claims that "Information is Physical."
A flavor of its conceptual antipode, Wheeler's "It from Bit,"
is the Church/Turing thesis: All natural processes can be
computed by a universal Turing machine. Physical laws then
become descriptions of subsets of actually observable, as
opposed to merely possible, computations. Bell correlations
imply a separation: Either beyond-Turing computations are
impossible in nature, or they can be carried out even by
single photons.