Anthony McCall's solid light film Line Describing a Cone (1973)is about the emergence of dimensionality in space. This paper uses Line Describing a Cone to discuss emergence as a material algorithmic process occurring across the media of informatic systems and installation art. Evolutionary models of emergence trace patterns, whether behavioural, spatial or genetic. Line Describing a Cone suggests the emergence of a new kind of mobilized viewer within gallery spaces who does not necessarily 'evolve' but who (through interruption and noise)becomes an interactive emergent part of the material processes of the work. Noise travels and generates the excess dimensionality within which an emergent material process can occur. It is contested here that emergence can only occur within noisy environments. Emergence then, introduces a process within which viewers interact with and experience art installations.