The registration for the "7th Workshop in the Physics of Fine-Tuning: The Fine-Tuning Argument" is free. Click here to register.
For any enquiries regarding this please email Leanne O'Donnell.
Rafael Alves Batista
Michael T. Hicks
VENUE & DIRECTIONS
The workshop will take place in Lindeman Theatre in the Clarendon Laboratory of the Physics Department on the 6th of October. Directions can be found in the here.
(University of Oxford)
|14.10-15.00||Fine-Tuning for Life in the Multiverse: A Panoramic View (abstract)||
(University of Groningen)
What kind of a fine-tuner? Some (unfinished) reflections on the relation between theism and design hypotheses (abstract)
Natalja Deng (Yonsei University)
Measure, Topology, and Probability in Cosmology (abstract)
Erik Curiel (Ludwig Maximillian University, Munich)
|17.10-17.40||Round Table Discussion|
This contribution offers a panoramic view of intricacies and challenges that arise in the assessment of empirical evidence concerning multiverse theories and the relevance of fine-tuning for life. First, I review the standard inference from fine-tuning for life to a multiverse and outline the inverse gambler's fallacy charge (Hacking, White) that has been levelled against this inference. Second, I argue that the debate concerning the severeness of this challenge has reached deadlock and explain why. Third, I point out a widely ignored di fference between the inference from fine-tuning to a multiverse on the one hand and paradigmatic instances of anthropic reasoning on the other. The key point is that the inference from fine-tuning to the multiverse treats the existence of living organisms, including observers, as calling for an explanation and infers the existence of a multiverse as the best candidate explanation. Anthropic reasoning of the type championed by cosmologists Dicke and Carter, in contrast, takes the existence of observers as background information that helps account for coincidences found between various measured parameters. Fourth, this contribution explores a novel version of the ne-tuning argument for the multiverse which, in contrast to the standard version, has the structure of Dicke's and Carter's anthropic arguments. Unlike the standard version of the argument, the novel version turns out not to be susceptible to the so-called inverse gambler's fallacy charge. Fifth, I conclude by assessing the enormous difficulties in establishing independent empirical evidence for or against specific multiverse theories that are highlighted by a recently proposed solution to the observer reference class problem in cosmology.
This talk is a response to John Hawthorne and Yoav Isaac’s recent defense of the Bayesian fine-tuning argument for design (‘Fine-tuning Fine-tuning’ (ms), ‘Misapprehensions about the fine-tuning argument’ (ms)). Suppose physicists find that many of the features that make the universe hospitable to life are such that their probability is extremely low in all ‘physically-respectable’ measures. H&I argue that this provides substantial evidence for the claim that the universe was designed by one or more agents, at least provided one assumes there is no multiverse. I comment on two of the responses they consider, namely one based on dismissive priors (a), and one based on a ‘God-of-the-gaps’ style objection by theistic design theorists (b). I suggest that there is a reading of (b) on which it amounts to a practice-based constraint on theistic conceptions, and that often, theistic conceptions that meet this constraint are vulnerable to (a).
I explain the difficulty of making various concepts of and relating to probability precise, rigorous and physically significant when attempting to apply them in reasoning about objects (e.g., spacetimes) living in infinite-dimensional spaces, working through several examples from cosmology. I focus on the relation of topological to measure-theoretic notions of and relating to probability, how they diverge in unpleasant ways in the infinitedimensional case, and are difficult to work with on their own as well in that context. Even in cases where an appropriate family of spacetimes is finite-dimensional, however, and so admits a measure of the relevant sort, it is always the case that the family is not a compact topological space, and so does not admit a physically significant, well behaved probability measure. Problems of a different but still deeply troubling sort plague arguments about likelihood in that context, which I also discuss. I conclude that most standard forms of argument used in cosmology to estimate the likelihood of the occurrence of various properties or behaviors of spacetimes have serious mathematical, physical and conceptual problems.