On the self-gravitating mass of political, cultural and sociological or information and communications contexts: it is more than a metaphor. There are elementary information and communications-system (logical, topological, relational and perhaps analytically-inevitable) dynamics which approximate to recursive self-gravitation and the literal reflexive warping of technological, economic, political, cultural and semantic spaces back upon, into and through themselves. There are aspects of holistic or global-systems analysis in which not only are informal approximations to self-gravitation of uniquely-compelling impact, but in which such internal, logical hyper-inflation almost inevitably ends up assuming this kind of shape and self-reflexive dynamical symmetry.
It is salient to acknowledge that there may be many such abstractions (or projections) of gravitational centre in integrated and self-inflating logically-incomplete information and communications systems. What in any one context of interpretation or dimensional “slice” of the possibility-space appears as a centre is just as easily rendered under alternative perspectives or under divergent recombinatory axioms as the periphery of another similarly abstract gravitational mass.
In some perhaps necessarily indistinct sense these are communications systems undergoing semantic and contextual frame-dragging, acceleration, compression and emergent-systems self-propagation. Stepping off from a clockwork world of linear dynamics and a simple algebra of actors, effects and geopolitical stages into a new conceptual vocabulary of complex and multidimensional, plastic spaces and warping logical dimensions of political, economic, social and cultural analysis; ditching an analytical steam engine for an explanatory tesseract.