Gerard James Milburn

In her paper, ‘The Open Universe: Totality, Self-reference and Time’, Ismael argues that the agent experience of dynamic time, in which the world comes into being, is more than ‘mere appearance’. The key to her argument is that the actual world includes agents (minds) and their corresponding agential (mental) activity, which Ismael describes as ‘the crucial step down from ‘mere appearance’ to ‘actuality’. We present here a model of an agent as a complex physical system with a view to providing a tenable illustration of Ismael’s schema for understanding the ‘actuality’ of time. The radical implication for physical time as a result is that there is, in Ismael’s words, ‘no pure … conception of the way [the] world is independently of ourselves and our representational activity’, but rather only ‘embodied and engaged’ knowledge of the world.

In her paper, 'The Open Universe: Totality, Self-reference and Time', Ismael argues that the agent experience of dynamic time, in which the world comes into being, is more than 'mere appearance'. The key to her argument is that the actual world includes agents (minds) and their corresponding agential (mental) activity, which Ismael describes as 'the crucial step down from 'mere appearance' to actuality'. We present here a model of an agent as a complex physical system with a view to providing a tenable illustration of Ismael's schema for understanding the 'actuality' of time. The radical implication for physical time as a result is that there is, in Ismael's words, 'no pure... conception of the way [the] world is independently of ourselves and our representational activity', but rather only 'embodied and engaged' knowledge of the world.

It is the prevailing paradigm in contemporary physics to model the dynamical evolution of physical systems in terms of a real parameter conventionally denoted as 't' ('little tee'). We typically call such dynamical models laws of nature' and t we call 'physical time'. It is common in the philosophy of time to regard t as time itself, and to take the global structure of general relativity as the ultimate guide to physical time, and so consequently the true nature of time. In this paper we defend the idea that physical time, t, is rather better defined as an operational modelling parameter: we measure relations between changing physical quantities using bespoke physical systems---i.e. clocks---that coordinate local coincidences. We argue that the sorts of physical systems that make good clocks---what we call precision clocks---are those that exhibit self-sustained oscillations known as limit cycles, which are ubiquitous in open, driven, stable, dissipative systems. We develop the physical and philosophical ramifications of this conception of physical time, particularly the notion that physical time does not track something 'out there' in the world. As a result, we speculate that physical time is perhaps not as different from manifest time as many philosophers of time (and apparently general relativity) seem to suggest.

Despite the tremendous empirical success of quantum theory there is still widespread disagreement about what it can tell us about the nature of the world. A central question is whether the theory is about our knowledge of reality, or a direct statement about reality itself. Current interpretations of quantum theory, regardless of their stance on this question, regard the Born rule as fundamental and add an independent state update (or ‘collapse’) rule to describe how quantum states change upon measurement. In this paper we present an alternative perspective and derive a unified probability rule that subsumes both the Born rule and the collapse rule. We show that this more fundamental probability rule can provide a rigorous foundation for informational, or ‘knowledge-based’, interpretations of quantum theory. Our result requires an assumption of instrument non- contextuality, a key notion that generalises previous approaches to non-contextuality. Therefore, the framework also permits one to consider non-contextuality in scenarios with arbitrary causal structure.