  It is a great pleasure to write this tribute in honor of Scott A. Smolka on
his 65th birthday. We revisit Goldin, Smolka hypothesis that persistent Turing
machine (PTM) can capture the intuitive notion of sequential interaction
computation. We propose a topological setting to model the abstract concept of
environment. We use it to define a notion of a topological Turing machine (TTM)
as a universal model for interactive computation and possible model for
concurrent computation.
