Relativity Doesn’t Prove the Block Universe

You’ve heard the slogan: relativity killed the universal “now,” so the universe must be a timeless four-dimensional block where past and future are just as real as the present.

It sounds like a deduction from physics.

But it isn’t.

It’s a metaphysical picture smuggled in—and then mistaken for what the equations themselves require.


The slide that makes the block feel inevitable

Relativity gives us a brilliantly disciplined way to represent constraints on physical processes: events, worldlines, invariants, and causal structure.

That’s the formal layer: bookkeeping that prevents contradictions when signals have finite speed and simultaneity depends on frame.

The block-universe move happens when we replace:

with

That is the Stage Assumption: time as a container, an arena, a theatre in which everything is already “placed.”

Changism starts from the opposite discipline:

time is a ledger over change, not a metaphysical stage beneath it.


The decisive point: the record-frontier

Here is the operational move that breaks the spell.

Let S be any embodied system that can store and use information: a lab, an organism, a computer, a scientific community.

Let Rₛ be S’s accessible record-network: stored traces, logs, memories, instrument states, received messages—whatever S can actually consult to constrain inference and action.

Now define:

Present-for-S = the frontier where new information becomes integrated into Rₛ in a way that can constrain what S does next.

This does not require a universal cosmic “now.”
It is fully compatible with relativity.

And it is not “mere perspective.”

Because it is the boundary between not having a record and having a record—between a constraint that exists for S and one that does not.

Once you see that, three asymmetries fall out that no paraphrase can dissolve:

Record asymmetry: you can consult a record only after it exists and is accessible.

Control asymmetry: S can influence which future records will exist, but cannot intervene to alter which records already constrain it.

Measurement asymmetry: outcomes become facts by record-closure—by stabilizing into durable constraints usable for later checking and coordination.

A tenseless description can describe these.

But the stronger eternalist claim is that “present” is only a linguistic posture with no corresponding physical asymmetry.

That claim fails here, because record-closure is a physical achievement, not a poetic mood.


One concrete example: synchronizing clocks

Take the simplest, relativity-friendly procedure: two labs synchronize clocks by exchanging signals.

Lab A sends a light pulse to lab B, timestamped by A’s clock.
B receives it and updates its clock setting (or its estimate of A’s time) by an explicit protocol.

Before reception, B does not have that timestamp in its record network; it cannot coordinate using it.

After reception, B now has a new stable record (a logged message); its constraint landscape changes; coordination becomes possible.

The block theorist replies: “All of that is tenselessly located in the manifold. No objective before/after—only relations.”

But notice what that reply risks.

It treats the operational difference between not having a record and having a record as a narrative overlay—when in the actual procedure that difference is the whole point.

Synchronization is achieved by a physical update—signal arrival, storage, and integration into a record-network—not by contemplating a diagram.

So the clean conclusion is:

Relativity’s geometry can model the relations.
But the inference “therefore becoming is unreal” is a metaphysical overreach that flattens the indispensable work done by record-closure.


A simple audit: facts, processes, physics

Here is the argument in its most compact, operational form:

This isn’t a taste dispute.

It is a constraint imposed by what “evidence,” “measurement,” and “experiment” actually are: the production of new records that can be used later.


“The block doesn’t remove asymmetry—it relocates it”

A block description can certainly represent the world as a completed pattern.

But the world it must represent still contains a robust asymmetry:

If eternalism says becoming “adds nothing,” then it owes an alternative account of why these asymmetries are not merely grammatical.

And if it just says “they’re in the block as relations,” then it hasn’t eliminated the asymmetry at all.

It has simply renamed it.


Biology makes the problem impossible to ignore

In biology, the dependence on ongoing activity is not optional metaphor.

A cell exists only because metabolism is ongoing.

An organism persists only because repair and regulation are ongoing.

A memory exists only because physical maintenance is ongoing.

Modern physics is similar in spirit: many things are stable only as maintained patterns of interaction.

So if reality were ontologically static in the strong sense—if nothing truly came to be, if no new facts were created—then we would not merely need a new interpretation.

We would need a new explanatory framework.

Not a reinterpretation of existing physics and biology, but a replacement of their dynamical explanatory core.


The “illusion of change” smuggles in change

Sometimes the block view is sold with an additional story:

“Change is an illusion produced by brains,” or, more mystifyingly, “produced by our movement through spacetime.”

But notice what these stories presuppose.

Brains are active physical systems. Illusions are produced by processing, updating, integrating signals into memory.

If you deny real becoming, you don’t get to help yourself to the activity that manufactures the “illusion.”

And the “movement through spacetime” line is worse: it sneaks the Stage Assumption back in, as if spacetime were an ontological medium we drift through—while simultaneously asking us not to count that drift as change.

It’s change denied with change furtively reinserted.


Changism 

Changism is not a rejection of relativity.

It is a discipline about what time-talk is for.

Events are interactions: meetings where systems constrain one another.

Outcomes are records: facts are record-closures—durable traces carried forward and cross-checked.

Objectivity is achieved by agreement: alignment of record-networks under shared standards, not a “view from nowhere.”

And the semantic payoff is simple:

Don’t treat past/present/future as regions.

Treat them as roles in the ledger:

Relativity is preserved: no preferred foliation, no master Now.

Geometry remains what it is best at being: a compression tool for consistent ledger relations—not a frozen stage.


What you can (and can’t) claim

Relativity does not prove eternalism.

It proves something subtler and more interesting: if you want public objectivity, you must do honest bookkeeping across finite signal speeds, frame-dependent simultaneity, and local standards.

The block universe is a metaphysical add-on that becomes tempting only when we slip back into the Stage Assumption—time as a container with everything “already there.”

If your ontology erases the very mechanism by which evidence is produced—record-closure and update—then it is not “based on physics.”

It is a diagram trying to outrank its own receipts.