 For a philosopher, the issues mooted here offer deep and rich veins for those contemplating, among other matters: the role of explanatory power in the assessment of physical theories; the interplay among observation, mathematical models, physical intuition and metaphysical predilection in the genesis of scientific knowledge; questions about the nature of the existence attributable to physical entities in spacetime and to spacetime itself; and the role of mathematical models of physical systems in our understanding of those systems, as opposed to their role in the mere representation of our knowledge of them. 