  Scientific collaboration is often perceived as a joint global process that
involves researchers worldwide, regardless of their place of work and
residence. Globalization of science, in this respect, implies that
collaboration among scientists takes place along the lines of common topics and
irrespective of the spatial distances between the collaborators. The networks
of collaborators, termed 'epistemic communities', should thus have a
space-independent structure. This paper shows that such a notion of globalized
scientific collaboration is not supported by empirical data. It introduces a
novel approach of analyzing distance-dependent probabilities of collaboration.
The results of the analysis of six distinct scientific fields reveal that
intra-country collaboration is about 10-50 times more likely to occur than
international collaboration. Moreover, strong dependencies exist between
collaboration activity (measured in co-authorships) and spatial distance when
confined to national borders. However, the fact that distance becomes
irrelevant once collaboration is taken to the international scale suggests a
globalized science system that is strongly influenced by the gravity of local
science clusters. The similarity of the probability functions of the six
science fields analyzed suggests a universal mode of spatial governance that is
independent from the mode of knowledge creation in science.
