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arxiv: 2606.07352 · v1 · pith:OIH6C7BInew · submitted 2026-06-05 · 🪐 quant-ph

Tests of constructor theory

Chiara Marletto , David Deutsch , Vlatko Vedral This is my paper

Pith reviewed 2026-06-27 21:43 UTC · model grok-4.3

classification 🪐 quant-ph
keywords constructor theoryquantum informationtask possibilityuniversal constructorexperimental testsphysical principlesdynamical laws
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The pith

Constructor theory's principles add novel constraints on possible tasks that yield experimental predictions beyond current dynamical laws.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

Constructor theory introduces physical principles expressed as statements about which tasks are possible or impossible for physical systems called constructors. These principles determine the full repertoire of a universal constructor capable of performing every physically allowed task. The paper establishes that the principles carry content supplementing existing dynamical laws and therefore generate new, testable predictions. It reviews concrete experimental proposals designed to probe those predictions and explores what confirmation or refutation would mean for quantum theory and any successor frameworks.

Core claim

The principles of constructor theory have novel physical content that supplements current dynamical laws, leading to new predictions for experimental tests. In this paper, we review the main experimental proposals to test the principles of constructor theory and discuss their implications for existing theories of physics and for their successors.

What carries the argument

Constructor-theory principles stated as constraints on the possibility or impossibility of tasks performed by constructors.

If this is right

  • The principles fix the complete set of tasks a universal constructor can perform.
  • Specific experiments can distinguish constructor theory from quantum theory alone.
  • Confirmation would require adjustments to any future theory that replaces current dynamical laws.
  • The tests bear directly on what counts as a possible physical transformation.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Success of the tests would tighten the link between information-theoretic constraints and physical possibility.
  • The same principles might later be applied to derive limits on computation or measurement that current theory leaves open.
  • Experimental designs reviewed here could be adapted to other extensions of quantum information that also emphasize task possibility.

Load-bearing premise

The principles supply physical content that cannot already be derived from existing dynamical laws and that the proposed experiments can isolate this extra content.

What would settle it

Perform one of the reviewed experiments; if the measured outcome on task possibility matches standard quantum predictions but contradicts the constructor-theory constraint, the claim of novel content is refuted.

Figures

Figures reproduced from arXiv: 2606.07352 by Chiara Marletto, David Deutsch, Vlatko Vedral.

Figure 1
Figure 1. Figure 1: Information media and superinformation media: quantum systems [PITH_FULL_IMAGE:figures/full_fig_p008_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Hybrid systems comprise a quantum probe Q (e.g. a qubit) and another ‘mystery’ system M whose laws are partially unknown and may not be quantum-mechanical. These hybrid systems are characterised by a hybrid scale (not micro or macro, but a mixture of those) and by unspecified hybrid dynamics (not clas￾sical, not quantum, but possibly more general ones). Typically, hybrid systems are studied using ad hoc as… view at source ↗
Figure 3
Figure 3. Figure 3: The entanglement-based witness of non-classicality. If M can entangle [PITH_FULL_IMAGE:figures/full_fig_p013_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Temporal witness of non-classicality. If [PITH_FULL_IMAGE:figures/full_fig_p016_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: The quantum homogeniser used to model the constructor-based irre [PITH_FULL_IMAGE:figures/full_fig_p021_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: The logic of self-reproduction with the replication-vehicle logic. An [PITH_FULL_IMAGE:figures/full_fig_p026_6.png] view at source ↗
read the original abstract

Constructor theory is a proposal to extend quantum information theory beyond both quantum theory and computation, to cover more general machines than programmable computers -- called constructors. It consists of newly conjectured physical principles that can be expressed as constraints on what tasks are possible, what are impossible, and why. These principles also determine the repertoire of the universal constructor, which is a programmable machine that can perform all physically possible tasks. The principles of constructor theory have novel physical content that supplements current dynamical laws, leading to new predictions for experimental tests. In this paper, we review the main experimental proposals to test the principles of constructor theory and discuss their implications for existing theories of physics and for their successors.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 0 minor

Summary. This manuscript is a review summarizing existing proposals for experimental tests of the principles of constructor theory. These principles are presented as conjectured constraints on possible and impossible tasks performable by constructors (general machines), determining the repertoire of a universal constructor, and asserted to supply novel physical content that supplements dynamical laws and yields new testable predictions.

Significance. If the reviewed experimental proposals can be implemented and the principles prove to have content independent of existing dynamical laws, the review could help consolidate and guide tests in quantum foundations. The paper does not derive new results, present original data, or include machine-checked proofs or parameter-free derivations, but compiles prior proposals and discusses implications.

major comments (1)
  1. [Abstract] Abstract: The central assertion that 'the principles of constructor theory have novel physical content that supplements current dynamical laws, leading to new predictions' is stated as a premise without a specific section or example within the review demonstrating a concrete prediction that cannot be derived from standard quantum theory or other existing frameworks; this is load-bearing for the paper's framing of the tests' significance.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their careful reading of the manuscript and for the recommendation of minor revision. We address the single major comment below.

read point-by-point responses

  1. Referee: [Abstract] Abstract: The central assertion that 'the principles of constructor theory have novel physical content that supplements current dynamical laws, leading to new predictions' is stated as a premise without a specific section or example within the review demonstrating a concrete prediction that cannot be derived from standard quantum theory or other existing frameworks; this is load-bearing for the paper's framing of the tests' significance.

    Authors: We agree that the abstract states the claim without an immediate, self-contained example. While the body of the review summarizes proposals from the literature in which such distinctions are argued to arise (particularly in the sections on thermodynamics and information), the manuscript does not itself derive or exhibit a concrete, side-by-side comparison. To address this directly, we will add a short, explicit example in the revised introduction (or a new short subsection) that contrasts one specific prediction with what follows from standard quantum theory alone. This will make the framing more robust without altering the review character of the paper. revision: yes

Circularity Check

0 steps flagged

Review paper; no derivation chain present

full rationale

This is a review summarizing prior experimental proposals for constructor theory principles. No equations, derivations, or new predictions are introduced in the manuscript that could reduce to self-definitions, fitted inputs, or self-citation chains. The abstract and framing refer to principles from earlier work, but the paper itself performs no load-bearing derivation or uniqueness argument that would qualify as circular under the specified criteria. The content is self-contained as a literature review against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Only the abstract is available; no specific free parameters, axioms, or invented entities can be extracted from the full text.

pith-pipeline@v0.9.1-grok · 5629 in / 980 out tokens · 23442 ms · 2026-06-27T21:43:53.879921+00:00 · methodology

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Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Constructor-Theoretic Optical Time: Delay, Phase, and Fisher Distinguishability as Physical Tasks

    physics.optics 2026-06 unverdicted novelty 6.0

    The authors reformulate optical time using constructor theory, interpreting Fisher information as a distinguishability resource and the Cramer-Rao bound as a statement of task impossibility for delay estimation under ...

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