Nicola Bamonti

Our best cosmological model, the LCDM model, predicts that in a finite time all unbound systems will cross a cosmic event horizon, meaning that no new empirical data can ever be gathered. The Universe has already entered this phase, in which cosmological sources of information are progressively disappearing. This prospect shows that the dependence of Bird's epistemic and Dellsén's noetic accounts of scientific progress on continuing empirical input is not merely a definitional feature of conditional accounts, but a boundary that cosmology itself guarantees will be reached. This paper is not revisionary: it does not alter these accounts, but clarifies their scope by situating them within this cosmologically mandated regime. As an outlook, I sketch a general account of scientific progress grounded in structural understanding, which could preserve a notion of progress even once observation is no longer possible—while leaving open the further question of whether progress ought in fact to continue under such conditions.

This paper challenges the notion of emergent time in quantum cosmology by examining the reconciliation of the timeless Wheeler–DeWitt equation with the Universe’s dynamical evolution. We critically evaluate the analogy between the Wheeler–DeWitt and Klein–Gordon equations, highlighting challenges for the identification of an emergent time parameter. We conclude that refining this analogy may lead to a better understanding of emergent time in quantum cosmology, though it is still not free from complications.

In General Relativity, reference frames must be distinguished from coordinates. The former represent physical systems interacting with the gravitational system, aside from possible approximations, while the latter are mathematical artefacts. We propose a novel three-fold distinction between Idealised Reference Frames, Dynamical Reference Frames and Real Reference Frames. This paper not only clarifies the physical significance of reference frames, but also sheds light on the similarities between idealised reference frames and coordinates. It also analyses the salience of reference frames to define local gauge-invariant observables and to propose a physical interpretation to diffeomorphism gauge symmetry.