Wednesday 23 November 2016 at Geneva – David Yates (University of Lisbon): Spacetime functionalism and empirical coherence
Abstract: Quantum gravity research seems to suggest that spacetime is not fundamental, but this in turn threatens the existence of the “local beables”—meters, pointers, dials—we observe to gain evidence for fundamental physical theories. How can a physical theory be justified if there are no local beables in its ontology? Spacetime functionalism promises a conservative truthmaking theory for empirical truths, which explains how it is that statements such as ‘the pointer moved to position 5 on the dial’ come out true even though the fundamental ontology is not straightforwardly spatiotemporal. There are several different functionalist positions available—depending on which concepts we take to be functional, and what roles we take to define them—and it isn’t always clear how they interact. Spacetime functionalists (Knox) argue that the concept of a spacetime is the concept of whatever it is that occupies a certain set of roles within physical theory. Because the concept of spacetime is topic-neutral, even if the fundamental quantum ontology turns out to be very unlike the spacetime of the manifest image, we should not conclude on that basis that there is no spacetime for local beables to occupy. The occupant of the spacetime roles may or may not be fundamental, and it may or may not be recognisable spatiotemporal. This theory shows us how a necessary condition on the truth of empirical statements is consistent with a non-spatiotemporal fundamental ontology, but stops short of a truthmaking theory for such statements. Spacetime occupant-functionalism (Wallace, Ney) and spacetime property-functionalism (Chalmers) offer topic-neutral analyses of our concepts of ordinary objects and spatiotemporal properties respectively, and jointly offer the promise of such a theory. In this talk I argue that property-functionalism fails, and that there is therefore no topic-neutral analysis of our ordinary empirical claims about local beables. I argue further that at least some spatiotemporal property concepts fail to have topic-neutral analyses because they are directly referring concepts that are at least partially transparent with respect to their referents. It follows, I suggest, that either the fundamental quantum ontology is spatiotemporal after all, or local beables inhabit a grounded spacetime. I suggest the latter, and conclude by considering whether a grounded spacetime might also be fundamental, hence ontologically emergent. In terms of technical difficulty, this talk rates 1/5
More details above.
Shamik Dasgupta’s talk on Wednesday 11/16/16 will not be the usual location at UIC, but in ETMSW 2217 (click for map) at 11am. More information above – Geneva and YouTube as advertised and as usual.
Not news about our project, but a resource that will be of interest to readers, and should be more widely known. Four years ago, philosophers and physicists got together to discuss the future of time in quantum gravity (and indeed linguistics and psychology). Videos of the talks – including Albert, Butterfield, Dowker, Ellis, Price, Rovelli, Sorkin, and more – are available here:
There was also an issue of Annals of the New York Academy of Science devoted to the meeting:
Apologies for old news, but I just remembered how interesting the meeting was – and relevant to our interests.
We have just posted video of the talks by Josh Norton, Tatyana Shestakova, Ko Sanders, and Marko Vojinovic. See Our YouTube Channel or click on ‘Speakers’ above. Enjoy.
After the Philosophy of Science Association meeting break, we are back for the final talks of the year, starting with Shamik Dasgupta (University of California, Berkeley) at UIC on Wednesday November 16th at 11am in Chicago. Please join us – more information above.
Physical Salience and Autonomy: Could Spacetime be an Emergent Phenomenon?
Abstract: There has recently been much interest in the question of whether space could be derivative from some kind of non-spatial structure. But what conditions must be satisfied if the resulting space is to be, to use Tim Maudlin’s phrase, “physically salient”? Some suggest that there is an epistemic
constraint to the effect that it must be “fully transparent” or “immediately intelligible” how space emerges out of the non-spatial structure. In particular, David Chalmers develops this constraint in terms of apriori entailment. But is there really an epistemic constraint like this? If so, why
? What is it about something being “derivative from” something else that requires this epistemic connection between the two? I will explore an answer to this latter question, thereby defending epistemic constraints like these from some recent objections. In terms of technical difficulty, this talk rates 1/5
If you are looking for the handout for our PSA presentation, they are here:
Live from/in Geneva (more details above):
Elena Castellani (University of Florence): Duality and emergence: the case of weak/strong duality
Abstract: The two notions of duality and emergence seem to be in an intriguing relation: on the one side, they seem to be closely connected, on the other side, they are clearly distinct —- perhaps even mutually exclusive? The key feature, in the case of duality, is the kind of equivalence that is entailed between the two theories (or the two descriptions of the same theory, in case of self-duality). In the case of emergence, the focus is rather on the aspect of novelty that the notion entails, and thus, apparently, on a lack of equivalence between the two theoretical descriptions. The dualities which are of great relevance in field and string theory, however, seem to be related to emergence: in many cases, the dual correspondence seems to give a form of emergence (new particles or new phenomena). How to combine these apparently contrasting features?
This talk is directly connected to the preceding talk by Sebastian de Haro discussing the relation between duality and emergence in the case of gauge/gravity duality (Geneva, 14.01.2016). Here, the same issue is discussed in another relevant duality case, that is, weak-strong duality or S-duality (as is usual to call it in the context of string theory) — a duality which has become a basic ingredient in field and string theories especially since the 1990s. In particular, the focus will be on the meaning of the dual correspondence between ‘elementary’ and ‘composite’ particles that this kind of duality apparently implies. At first sight, the correspondence could be interpreted as giving rise to new objects or a new way of looking at the same objects. The question is then how to intend this novelty feature given the symmetric character of the dual correspondence. The general aim is to explore whether and in which sense comparing duality and emergence can be a helpful exercise for the philosophical reflection on their meaning.
In terms of technical difficulty, this talk rates 3/5
We are hosting a lunch at the PSA in Atlanta, on Thursday, November 3, 12:20 pm – 1:20 pm. Seats are limited (and going fast), but please join us to talk about quantum gravity. You can sign up here: http://www.signupgenius.com/go/20f0f4ea8ad23a0f58-psa2016
See you there!
A final reminder to please submit your papers for our annual essay prize – $1000, a visit to UIC or Geneva, and publication in an edited collection are at stake! More details are here:
• Wednesday 19 October 2016 at Geneva – Marko Vojinovic (University of Belgrade): Quantum gravity, metaphysics, spacetime emergence and locality
Abstract: We will present a brief overview of the various approaches to quantum gravity, with the emphasis on the following questions: (1) why quantize gravity, (2) how to quantize gravity, (3) what is spacetime emergence, and (4) the role of metaphysics in all the above. We will also touch upon the foundational issues of diffeomorphism-symmetric quantum mechanics, and the interplay between locality, the measurement problem, the Schrodinger’s cat paradox and quantum cosmology, leading to some open questions at the foundation of both gravity and quantum mechanics.
In terms of technical difficulty, this talk rates 4/5