Simultaneity and completed records: SMM/DTT and Presentism and the growing-block universe

01The question behind the comparison

Two events being available in one record does not imply that they happened simultaneously. A photograph can combine light emitted at different times; an archive can collect reports made in different places; a later observer can compare events that were never in causal contact. DTT’s outer completion is most naturally understood first as availability of a record. Identifying it with a universal simultaneous present would be a further physical claim, requiring a synchronization rule and an account of its relation to relativity.

Relativistic simultaneity is defined relative to a chosen inertial frame for spatially separated events. Local coincidence is different: two clocks meeting at one event can compare readings without convention about distant simultaneity. A source-based theory may contain a deeper ordering, but if that order selects an observable preferred frame it has physical consequences. If it never affects any observable, it functions as underlying explanatory structure. Keeping these alternatives distinct prevents a metaphysical unity of source from silently becoming an absolute laboratory time.

The six nested inner levels concern the formation of accessible relations and do not automatically supply six hypersurfaces or a seventh global slice. Nesting is a dependency structure. A completion relation might instead form a partial order, allowing some records to be incomparable until a later interaction combines them. Such a construction could preserve the difference between local causal precedence and frame-dependent order at a distance. The positive DTT question is then how a common source produces a consistent network of local records without requiring every observer to share one instantaneous world-picture.

02The single-source and nested-time proposal

SMM begins with one nonspatial generative source. DTT distinguishes its inner production from the outer order in which completed results become accessible. The six inner levels are nested functional dependencies within that production; the seventh denotes outer completion. They are not six independent clocks, six spatial directions, or six simultaneously occupied temporal axes. This distinction makes the framework more specific than a general claim that everything changes: it asks how a world of persistent relations can be generated before its spatial representation is taken for granted. ^[2]

03The comparator’s explanatory structure

Presentism restricts concrete temporal existence to the present; the growing-block view includes the past and present while excluding the future. The distinction is decisive for a record-based ontology. A present record of yesterday and yesterday’s continuing existence are different claims. Broad’s treatment of becoming supplies the historical growing-block comparator; the presentist alternative sharpens what an archive does and does not establish.

Suppose a stone bears an inscription describing a vanished ceremony. A presentist can treat the inscription as a current object with a history. A growing-block theorist can additionally include the ceremony itself in reality. Both can agree about what the inscription says. The disagreement therefore cannot be settled by pointing to a stored record alone. SMM/DTT gains precision by stating whether renewal preserves past events, preserves only present traces, or uses another form of persistence. Relativity adds the separate question of how a privileged present, if proposed, relates to spatially separated events. ^[1]

04The precise agreement and difference

Presentism and a growing block commonly appeal to a privileged boundary between what is actual and what is not yet actual. For spatially separated events, relativity makes the physical definition of such a boundary nontrivial. DTT’s common source does not automatically supply an observable synchronization rule. A single origin and a single simultaneous present are different commitments.

A completion-based approach could instead make the boundary local: an event becomes available within a record network, and different networks become mutually comparable through later interactions. This retains meaningful becoming without immediately identifying it with one global spacelike slice. If DTT requires a global slice, the source dynamics should specify it and explain how relativistic clock observations emerge. The comparison therefore opens two concrete interpretations rather than presuming a conflict is already solved. It also distinguishes persistence of past events in a growing block from the practical accessibility of their records. A boundary of existence, a boundary of knowledge and a boundary of causal influence need not be the same surface. ^[1]

05Worked example: what follows and what does not

In an inertial frame, let two events be simultaneous and separated by distance L along x: Δt = 0 and Δx = L. A second frame moving at speed v assigns Δt′ = −γvL/c², with γ = 1/√(1−v²/c²). Unless v or L vanishes, the events are not simultaneous in that frame. Their eventual inclusion in the same notebook does not change this result. For timelike-related events, however, all inertial frames preserve their causal order. A DTT record relation should therefore distinguish causal ancestry from the order imposed by a particular display or coordinate system.

06What this comparison contributes

This yields a useful design principle for comparisons: shared source, shared information and shared simultaneity are three different claims. The first concerns ontology, the second communication or correlated access, and the third spacetime conventions or structure. A rigorous completion theory could explain why local observers agree when their records overlap while legitimately disagreeing about distant simultaneity. That would connect unity with the observed plurality of perspectives in a mathematically meaningful way.

THE SAME QUESTION, DIFFERENT STARTING POINTS

The comparison at a glance

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