Two reflections from theoretical cosmology provide the inspiration for this paper. The first is an acknowledgement that light is but a one-dimensional signal of (non)human knowability of the properties of the universe. The second is the claim that properties as-of-yet unknowable are mathematically thinkable, albeit in the absence of observational verification. Current cosmological debates concerning the (non)existence of manifold topologies of the multiverse (e.g. Smolin 2015) provide a rich context in which to both stay with and trouble claims for (un)knowability as a resource for tentatively grasping the radically insensible (Yusoff 2013). Indeed the deep recesses of the (non)existent multiverse promise to usefully probe further the very meanings of (non)human perceptibility. This paper will practice a recent interdisciplinary experiment between an artist, anthropologist and cosmologist as they exchange theoretical and material resources with which they individually and collectively trouble the limits of (im)perceptibility posed by the example given. Theoretical reflection on the status of mathematics as (non)human signal, will tentatively steer between accounts of mathematical ontology (Badiou, Meillassoux) and feminist materialist consideration of mathematics as human-nonhuman semiotic exchange (e.g. Kirby). We reflect upon the problem of seeking ‘illumination’ of dark objects through the example of Art practice, where ‘knowing’ is deliberately postponed and a state of being ‘in the dark’ is essential to enriched understanding (Jones 2013).The paper will be framed by a wider-arching question concerning the possibilities of the utter (ir)relevance of such radically ‘dark spaces’ for anthropocenic thinking.