Sigma Club

In this talk we will consider Special Relativity and General Relativity. In Special Relativity there is a single consideration which, above all others, is the heart of the theory. This is reciprocity - very briefly, the absolute equality of the inertial frames employed. We show that, so called , time dilation is reciprocally inconsistent and must be replaced by a…

I reconstruct the discovery of the Higgs boson as a case of a causal inference. I will argue that the example shows how scientists are able to infer the existence of an unobservable entity without relying, hypothetically, on the prior assumption of its existence.

This event has been cancelled as of 22 February. Apologies for any inconvenience.

Abstract: Scientists and philosophers who seek, or advocate seeking, a “theory of everything” (e.g., string theory, Thomas Nagel’s panpsychic theory, David Chalmers’ “construction of the world”) want to produce a grand, unifying theory that can explain everything on the basis of fundamental laws and constituents of the universe.  Advocates of this idea offer very general empirical, or a priori, or…

Abstract: Collapse models are modifications of quantum theory where the wave function is treated as physically real and the collapse of the wave function is a physical process. This appears to introduce a time reversal asymmetry into the dynamics of the wave function since the collapses affect only the future state. We challenge this conclusion, showing that if the physically…

Abstract. According to the present state of knowledge, the Universe in small scales is described by the laws of quantum theory. On the other hand, the fundamental theory of gravity is believed to be Einstein's relativity. Its effects become relevant when we consider large masses or (equivalently) large energies. One of the main features of Einstein's theory is the fact…

To avoid paradox, I maintain that two simple tensed conditionals are true: (i) if the atom has decayed then the cat is dead; (ii) if the atom has not decayed then the cat is alive. So long as it is true at some time that the atom decays then it follows from tense logic (under mild constraints) that at all…

Abstract: In Boltzmannian statistical mechanics macro-states supervene on micro-states. This leads to a partitioning of the state space of a system into regions of macroscopically indistinguishable micro-states. The largest of these regions is singled out as the equilibrium region of the system. What justifies this association? We review currently available answers to this question and find them wanting both for…

Standard approaches to the interpretation of physical theories require a structurally unambiguous characterization of the models of a theory. In this talk I argue that the nature of the empirical support for quantum field theory does not warrant commitment to one particular type of structure as constitutive of the theory. Rather, the empirical adequacy of some models of the theory…

Abstract: The canonical formalism of general relativity affords a particularly interesting characterisation of the infamous hole argument. It also provides a natural formalism in which to relate the hole argument to the problem of time in classical and quantum gravity. In this paper I will examine the connection between these two much discussed problems in the foundations of spacetime theory…

Abstract: The conflict between an objective passage of time and relativistic physics is sometimes summed up as follows: first, relativistic physics implies a ‘B-theoretic’ or ‘block universe’ view of time, and second, the B-theory implies that there is no objective passage. Here, I’ll take issue with the second entailment claim. I begin by presenting the case for veridicalism, the claim…

Abstract: TBA

Abstract: This talk proposes to re-examine the parity-of-reasoning or double-standard fallacy argument, which favours a time-symmetric Gold universe model over a cosmological arrow of time. There are two reasons for this re-examination. One is empirical: 1) the recent discovery of an expanding and accelerating universe questions the symmetry assumption of the Gold universe on empirical grounds; 2) the other is…

Abstract: This article develops a model-based account of the standardization of physical measurement, taking the contemporary standardization of time as its central case study. To standardize the measurement of a quantity, I argue, is to legislate the mode of application of a quantity concept to a collection of exemplary artefacts. Legislation involves an iterative exchange between top-down adjustments to theoretical and…