The indeterminate present

ABSTRACT

A non-solipsist form of presentness is usually thought to require the non-relative co-presentness of space-like separated events, where this requirement further implies the non-relative simultaneity of these events. Since special relativity is thought to rule out any global, non-relative simultaneity, typical non-solipsist forms of presentness are taken to be inconsistent with special relativity. To address this problem, we re-explain the relationship between the non-solipsism of presentness and co-presentness by appealing to metaphysical indeterminacy. We propose presentness indeterminacy, the thesis that where an event, p, is determinately present, any event in space-like relation to p lacks a determinate tense. We argue that for many theories of time, indeterminate co-presentness is all that the non-solipsism of presentness requires. Since there is no determinate co-presentness, the inconsistency between presentness and special relativity in these theories disappears.

KEYWORDS:

• Presentness
• A-theory
• special relativity
• indeterminacy
• solipsism

Acknowledgments

We would like to thank the audience at the Society for the Metaphysics of Science Annual Conference (Toronto, November 2019) for very helpful comments on an earlier version of this paper.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 This characterization of A-theories in terms of obtainment simpliciter is the counterpart of Zimmerman’s (2005, 433) and Skow’s (2012, 223) in terms of truth simpliciter. According to Zimmerman (2005, 433), no matter what ontology of propositions one adopts, an A-theorist may insist (and no self-respecting B-theorist should accept) that ‘some of these things are true, simpliciter, and that this class includes ones that will become or once were false.’ This kind of truth, which is not relative to anything, is to be distinguished from various kinds of relative truth, such as true-at-a-time or true-simultaneously-with-such-and-such-event, etc.

2 Tensed facts for Fine (2005) include facts like [Fine is sitting] or [Fine is standing]. The A-facts in this paper have the form [an event is present], which should be distinguished from tensed facts like [Fine is sitting]. Fine’s two tensed facts are incompatible because one cannot be both sitting and standing, whereas A-facts like [my eating breakfast is present] and [my eating lunch is present] are incompatible because two non-simultaneous events cannot both be present. A-facts of this latter kind can be regarded as a special kind of tensed fact in Fine’s (2005) terms. The A-fact theory accepts realism about tensed facts and absolutism about how tensed facts constitute reality, but it is silent about neutrality, according to which reality is not inclined to one particular time, and coherence, according to which reality is constituted by compatible facts.

3 If presentism is formulated in such a way that it is compatible with eternalism (e.g. Savitt 2006), then we see no reason why our account should not underwrite presentism. Furthermore, by restricting our account to eternalist theories of time, we hope to avoid the worry that presentness amounts to existence, and hence is not a property (Craig 1997).

4 By a location operator we mean an operator that has eigenstates in which the state is non-zero only within some finite spatial region. We do not mean the position operator, since perfectly precise position eigenstates are not well-defined physical states.

5 We assume that presentness is strictly point-like, at least as an idealization.