  In this paper, we introduce 'public computation' as a genre of learning
environments that can be used to radically broaden public participation in
authentic, computation-enabled STEM disciplinary practices. Our paradigmatic
approach utilizes open source software designed for professional scientists,
engineers and digital artists, and situates them in an undiluted form,
alongside live and archived expert support, in a public space. We present a
case study of DigiPlay, a prototypical public computation space we designed at
the University of Calgary, where users can interact directly with scientific
simulations as well as the underlying open source code using an array of
massive multi- touch screens. We argue that in such a space, public
interactions with the code can be thought of as boundary work and play, through
which public participation becomes legitimate scientific act, as the public
engages in scientific creation through truly open-ended explorations with the
code.
