Target space ≠ space

Quantum gravity and the nature of space and time

“…But according to physicists, dual pictures describe a common reality; this view undermines a direct interpretation of the background manifolds as accurate representations of spacetime. Huggett (forthcoming) argues that we cannot identify the background manifold with spacetime. The argument is based on considering T‐dualities in string theory where two different background manifolds constitute a dual pair; in this case, they have circular compact dimensions forming circles of different radii.…”

Priority Monism Beyond Spacetime

“…T-duality describes the correspondence between two apparently different physical situations: when one of the extra dimensions posited by string theory is compactified in a big circle or in very small circle. A solution with a compactification radius R in one dual is equivalent to a solution with radius L 2 /R in the other dual, where L is the string length (see for instance Matsubara 2013, 481 andHuggett, 2017). As Matsubara puts it:…”

“…Indeed, in the same way substantivalist spacetime is not a necessary component of priority monism, the view that spacetime is fundamental is not required in order to get priority monism off the ground. Let me call the new kind of priority monism that states that spacetime is not fundamentally real the "nonrelation obtaining between the non-perturbative more fundamental string theory and the less fundamental perturbative string theories, it remains that there the target spaces described by the perturbative string theories may not be identified with the even less fundamental phenomenological spacetime described by general relativity (see Huggett, 2017). spatiotemporal priority monist view".…”

Incubating a future metaphysics: quantum gravity

“…I will refer to this assumption as "presentism". 16 Because we take existence to be attached only to the present, there is a question for how to assign truth values to statements about future contingents. The puzzle over future contingents goes back at least as far as Aristotle.…”