  In this paper we illustrate the tension between mainstream 'normal',
'unorthodox' and 'fringe' science that is the focus of two ongoing projects
that are analysing the full ecology of physics knowledge. The first project
concentrates on empirically understanding the notion of consensus in physics by
investigating the policing of boundaries that is carried out at the arXiv
preprint server, a fundamental element of the contemporary physics publishing
landscape. The second project looks at physics outside the mainstream and
focuses on the set of organisations and publishing outlets that have mushroomed
outside of mainstream physics to cover the needs of 'alternative',
'independent' and 'unorthodox' scientists. Consolidating both projects into the
different images of science that characterise the mainstream (based on
consensus) and the fringe (based on dissent), we draw out an explanation of why
today's social scientists ought to make the case that, for policy-making
purposes, the mainstream's consensus should be our main source of technical
knowledge.
