The Geneva Symmetry Group, Beyond Spacetime, and the Space and Time After Quantum Gravity Project are happy to present
Oliver Pooley (Oxford):
Relativity and the Growing Block
Wednesday, 13 April, 16:15
2, Rue De-Candolle, Room L107 [Map: http://www.openstreetmap.org/]
Anyone who wishes to attend this talk is welcome. The talk will be 3 Einsteins (out of 5).
Abstract: I discuss two problems that stand in the way of reconciling relativistic physics and the growing block view of time. The first problem concerns the status of simultaneity and the present. A metaphysics of time that avoids introducing a preferred simultaneity relation can claim to be more thoroughly relativistic than one that does. A B-theoretic “block universe” model of time can clearly be relativistic in this sense. In other work I have argued that a shrinking tree model that embraces relativism (in Kit Fine’s sense) can be appropriately relativistic. I consider a Growing Block view fashioned along similar lines, and relate it to recent claims by some physicists (Sorkin, Dowker) to the effect that Causal Set Theory offers a physically respectable model of the passage of time.
The second problem concerns the interpretation of spatiotemporal relations that hold of events within the Growing Block. Many (including some physicists, such as George Ellis) suppose that a global present, and a metaphysically preferred simultaneity relation, are compatible with the letter of relativity. Adopting this view, one might further claim that for a Growing Block model to be relativistic it is merely required that the physics and spacetime structure of the ever growing block satisfies relativistic laws (Earman). However, the natural interpretation of such models leaves the view vulnerable to the Now now” objection. A promising response in the non-relativistic context insists that the (spatio)temporal structure of the ever growing Block is to be reduced to primitive tense (Correia and Rosencrantz). I explore the difficulties faced when seeking to recover relativistic spatiotemporal relations along these lines.