Bryan Roberts (London School of Economics) will be visiting the Geneva Symmetry Group (GSG) this week. The GSG is happy to present two talks by him, a more formal talk on Wednesday, and an informal seminar on Thursday (abstracts below):
Wednesday, 13 March 2019, at 18:15 in Room L208 (Landolt):
Bryan Roberts (London School of Economics): Time reversal
Thursday, 14 March 2019, at 16:15 in room B002 (Bastions):
Bryan Roberts (London School of Economics): On the future of the weakly interacting arrow of time
Anyone who wishes to attend is welcome.
Wednesday, 13 March 2019 in Room L208 (Landolt) – Bryan Roberts (London School of Economics): Time reversal
Abstract: What does it mean to “reverse time”? The idea sounds sci-fi, but plays an essential role in modern physics. This talk begins with an easy-going overview of how physicists understand time reversal, how it’s related to the philosophy of time and its direction, and why all this matters. I then review a competing, seemingly-intuitive philosophical account of time reversal, but which concludes that physicists have been wrong about it for a hundred years. I finally argue that we should resist this competing account, and stick with the physicists on the meaning of time reversal, both from a philosopher’s and from a physicist’s point of view.
In terms of technical difficulty, this talk rates 2/5.
Related paper (not representative of talk difficulty – but for interested students, see especially the open problems at the end): http://philsci-archive.pitt.edu/15033/
Thursday, 14 March 2019 in Room B002 (Bastions) – Bryan Roberts (London School of Economics): On the future of the weakly interacting arrow of time
Abstract: This discussion is a tour of how the laws of nature can distinguish between the past and the future, or be T-violating. I argue that, in terms of the basic argumentative structure, there are really just three approaches currently being explored. I show how each is characterised by a symmetry principle, which provides a template for detecting T-violating laws even without knowing the laws of physics themselves. Each approach is illustrated with an example, and the prospects of each are considered in extensions of particle physics beyond the standard model, and in particular in the search for a better understanding of Baryon asymmetry in the universe.
Reference: B.W. Roberts, ‘Three merry roads to t-violation’, http://philsci-archive.pitt.edu/9851/.