• Wednesday 13 December 2017 at Geneva – Karen Crowther (Geneva): When do we stop digging? Necessary conditions on a fundamental theory
Abstract: In seeking an answer to the question of what it means for a theory to be fundamental, it is enlightening to ask why the current best theories of physics are not generally believed to be fundamental. This reveals a set of conditions that a theory of physics must satisfy in order to be considered fundamental (although it is a further question whether a theory’s satisfaction of these necessary conditions is sufficient for it to be considered fundamental). Physics aspires to describe ever deeper levels of reality, which may be without end. Ultimately, at any stage we may not be able to tell whether we’ve reached rock bottom, or even if there is a base level–nevertheless, I aim here to draft a checklist to help us identify when to stop digging, in the case where we may have reached a candidate for a final theory. I begin by outlining some of the different conceptions of fundamentality associated with modern physics, before explaining why neither our current best theory of matter and forces (the standard model of particle physics), nor our current best theory of spacetime (general relativity), are generally considered fundamental. Following this, I present the necessary conditions that physicists apparently place on a fundamental theory, and I explore what these tell us about the nature of fundamentality. In terms of technical difficulty, this talk rates 1/5
With apologies for the delay, we have now posted Laura Ruetsche’s talk from the spring. Find it above under speakers, or on our YouTube channel here: Renormalization Group Realism: An Unduly Skeptical Review
On Wednesday 15 November 2017 at UIC (11.15am local time), Laurent Freidel (Perimeter) will speak on The Geometry of Relative Locality.
Abstract: In this talk I will describe the fundamental tension that forbids us in my view to reconcile gravity with the quantum. I will explain how this tension forces us to profoundly revise the concept of locality and that this can be done by letting go of the hypothesis of Absolute locality. I will formulate what relaxing this hypothesis means and will describe our attempts to flesh out the concept of relative locality. I will also exemplify what relative locality is into specific examples. In particular, we will show how these ideas allows us to natural interpret geometrically the T-duality symmetry of string theory. This symmetry will be seen as relativistic change of frame in a modular space, a notion of space that replaces Minkowski for quantum geometry. I will also show how the geometry of relative locality is intimately linked with generalized geometry and the geometry of quantum mechanics via a natural structure on phase space called Born geometry. Finally, and if time permits, I will comment how relative locality can shade a bright new light on the problem of unification. This talks involves several new important concepts: relative locality, generalized geometry, modular space, Born geometry. I will try to present them in a non technical manner as much as possible. In terms of technical difficulty, this talk rates 4/5
Full details above on the speakers page.
In the last month we have added videos of lectures by Mike Miller, Nic Teh, and Alexei Grinbaum – enjoy on our YouTube channel or via the Speakers page.
My paper on T-duality, Target Space ≠ Space was finally published in Studies in History and Philosophy of Modern Physics (though the preprint has been on their website for the last two years). If you are interested, you can get a free copy here for the next few weeks: https://authors.elsevier.com/a/1VmQs4q92pgchV. – Nick
Our YouTube channel now has some interesting 5 minute interviews that George Musser conducted with people at our summer conference: so far with Karen Crowther, Daniele Oriti, and Daniel Sudarsky. You can find them in the BST-POP playlist. Enjoy!
On Wednesday 18 October 2017 please join us at UIC (or at Geneva via livestream, or on our YouTube channel) to hear David Wallace (USC) speaking on “The Case for Black Hole Thermodynamics”
Abstract: I give a fairly systematic and thorough presentation of the case for regarding black holes as thermodynamic systems in the fullest sense (contra recent work by Dougherty and Callender), with particular attention to (i) the availability in classical black hole thermodynamics of a well-defined notion of adiabatic intervention; (ii) the power of the membrane paradigm to make black hole thermodynamics precise and to extend it to local-equilibrium contexts; (iii) the central role of Hawking radiation in permitting black holes to be in thermal contact with one another; (iv) the wide range of routes by which Hawking radiation can be derived and its back-reaction on the black hole calculated; (v) the interpretation of Hawking radiation close to the black hole as a gravitationally bound thermal atmosphere.
More information on all talks above.
• Wednesday 27 September 2017 at Geneva – Alexei Grinbaum (CEA-Saclay/LARSIM): How device-independent approaches change the meaning of physical theory
Abstract: Dirac sought an interpretation of mathematical formalism in terms of physical entities and Einstein insisted that physics should describe “the real states of the real systems”. While Bell inequalities put into question the reality of states, modern device-independent approaches do away with the idea of entities: physical theory may contain no physical systems. Focusing on the correlations between operationally defined inputs and outputs, device-independent methods promote a view more distant from the conventional one than Einstein’s `principle theories’ were from `constructive theories’. On the examples of indefinite causal orders and almost quantum correlations, we ask a puzzling question: if physical theory is not about systems, then what is it about? Device-independent models suggest that physical theory can be `about’ languages. This answer indicates a direction for moving beyond quantum theory. In terms of technical difficulty, this talk rates 4/5
Last call for entries to the 2017 essay contest – the deadline is September 15th.
Apologies that things have been quiet over the summer – we will soon have news of the 2017-18 program. Watch this spot!
Please consider entering our essay contest – winners receive $1000 and an invitation to speak. We will consider original work on the philosophical foundations of quantum gravity (including metaphysical issues arising in connection with such theories). Deadline: 9/15/17
Full details are above, or here: https://beyondspacetime.net/2017-essay-prize-contest/