BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Affine balance: algebraic spacetime functionalism as a guide to id
 entifying spacetime - Tushar Menon (University of Oxford)
DTSTART:20170503T120000Z
DTEND:20170503T133000Z
UID:TALK72516@talks.cam.ac.uk
CONTACT:31287
DESCRIPTION:Our two most empirically successful theories\, quantum mechani
 cs and \ngeneral relativity\, are at odds with each other when it comes to
  several \nfoundational issues. The deepest of these issues is also\, perh
 aps\, the \neasiest to grasp intuitively: what is spacetime? Most attempts
  at \ntheories of quantum gravity do not make it obvious which degrees of 
 \nfreedom are spatiotemporal. In non-general relativistic theories\, the \
 nmatter/spacetime distinction is adequately tracked by the \ndynamical/non
 -dynamical object distinction. General relativity is \ndifferent\, because
  spacetime\, if taken to be jointly\, but with some \nredundancy\, represe
 nted by a smooth manifold and a metric tensor field\, \nis not an immutabl
 e\, inert\, external spectator. Our \ndynamical/non-dynamical distinction 
 appears no longer to do the work for \nus\; we appear to need something el
 se. In the first part of this talk\, I \npush back against the idea that t
 he dynamical/non-dynamical distinction \nis doomed. I motivate a more gene
 ral algebraic characterisation of \nspacetime based on Eleanor Knox’s sp
 acetime functionalism\, and the \nHelmholtzian notion of free mobility. I 
 argue that spacetime is most \nusefully characterised by its (local) affin
 e structure.\n\nIn the second part of this talk\, I consider the debate be
 tween Harvey \nBrown and Oliver Pooley\, on one hand\, and Michel Janssen 
 and Yuri \nBalashov\, on the other\, about the direction of the arrow of e
 xplanation \nin special relativity. Characterising spacetime using algebra
 ic \nfunctionalism\, I demonstrate that only Brown’s position is neutral
  on \nthe substantivalism–relationalism debate. This neutrality may prov
 e to \nbe highly desirable in an interpretation of spacetime that one hope
 s \nwill generalise to theories of quantum gravity -- it seems like poor \
 npractice to impose restrictions on an acceptable quantum theory of \nspac
 etime based on metaphysical prejudices or approximately true \neffective f
 ield theories. The flexibility of Brown’s approach affords us \na theory
 -dependent a posteriori identification of spacetime\, and \narguably count
 s in its favour. I conclude by gesturing towards how this \nconstruction m
 ight be useful in extending Brown’s view to supersymmetric \nfield theor
 ies (and theories of quantum gravity).
LOCATION:Seminar Room 2\, Department of History and Philosophy of Science
END:VEVENT
END:VCALENDAR