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Constructor theory is a proposal for a new mode of explanation in fundamental physics in the language of ergodic theory, developed by physicists David Deutsch and Chiara Marletto, at the University of Oxford, since 2012.[1][2] Constructor theory expresses physical laws exclusively in terms of which physical transformations, or tasks, are possible versus which are impossible, and why. By allowing such counterfactual statements into fundamental physics, it allows new physical laws to be expressed, such as the constructor theory of information.[3][4]

Overview

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The fundamental elements of the theory are tasks: the abstract specifications of transformations as input–output pairs of attributes. A task is impossible if there is a law of physics that forbids its being performed with arbitrarily high accuracy, and possible otherwise. When it is possible, a constructor for it can be built, again with arbitrary accuracy and reliability. A constructor is an entity that can cause the task to occur while retaining the ability to cause it again. Examples of constructors include a heat engine (a thermodynamic constructor), a catalyst (a chemical constructor) or a computer program controlling an automated factory (an example of a programmable constructor).[3][4]

The theory was developed by physicists David Deutsch and Chiara Marletto.[4][5] It draws together ideas from diverse areas, including thermodynamics, statistical mechanics, information theory, and quantum computation.

Quantum mechanics and all other physical theories are claimed to be subsidiary theories, and quantum information becomes a special case of superinformation.[4]

Chiara Marletto's constructor theory of life builds on constructor theory.[6][7]

Motivations

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According to Deutsch, current theories of physics, based on quantum mechanics, do not adequately explain why some transformations between states of being are possible and some are not. For example, a drop of dye can dissolve in water, but thermodynamics shows that the reverse transformation, of the dye clumping back together, is effectively impossible. We do not know at a quantum level why this should be so.[1] Constructor theory provides an explanatory framework built on the transformations themselves, rather than the components.[3][4]

Information has the property that a given statement might have said something else, and one of these alternatives would not be true. The untrue alternative is said to be "counterfactual". Conventional physical theories do not model such counterfactuals. However, the link between information and such physical ideas as the entropy in a thermodynamic system is so strong that they are sometimes identified. For example, the area of a black hole's event horizon is a measure both of the hole's entropy and of the information that it contains, as per the Bekenstein bound. Constructor theory is an attempt to bridge this gap, providing a physical model that can express counterfactuals, thus allowing the laws of information and computation to be viewed as laws of physics.[3][4]

Outline

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In constructor theory, a transformation or change is described as a task. A constructor is a physical entity that is able to carry out a given task repeatedly. A task is only possible if a constructor capable of carrying it out exists, otherwise it is impossible. To work with constructor theory, everything is expressed in terms of tasks. The properties of information are then expressed as relationships between possible and impossible tasks. Counterfactuals are thus fundamental statements, and the properties of information may be described by physical laws.[4] If a system has a set of attributes, then the set of permutations of these attributes is seen as a set of tasks. A computation medium is a system whose attributes permute to always produce a possible task. The set of permutations, and hence of tasks, is a computation set. If it is possible to copy the attributes in the computation set, the computation medium is also an information medium.

Information, or a given task, does not rely on a specific constructor. Any suitable constructor will serve. This ability of information to be carried on different physical systems or media is described as interoperability and arises as the principle that the combination of two information media is also an information medium.[4]

Media capable of carrying out quantum computations are called superinformation media and are characterised by specific properties. Broadly, certain copying tasks on their states are impossible tasks. This is claimed to give rise to all the known differences between quantum and classical information.[4]

See also

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References

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Bibliography

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Constructor theory

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Constructor theory is a proposed framework for fundamental physics that reformulates the laws of nature in terms of a dichotomy between possible and impossible physical transformations, rather than relying on initial conditions and to predict trajectories. Developed primarily by physicist and researcher at the , it seeks to express all fundamental scientific theories using this paradigm, providing a unified approach to phenomena that are difficult to address in traditional physics. At its core, constructor theory posits that the laws of physics determine which transformations of physical systems can be reliably performed and which cannot, abstracting away from specific mechanisms to focus on general principles. Central to this are constructors, entities—such as machines, catalysts, or processes—that can cause specific tasks (defined as input-output state pairs) to occur repeatedly without degrading their own ability to do so. A task is deemed possible if it can be performed with arbitrarily high accuracy by some constructor, and impossible otherwise; this framework thus identifies fundamental prohibitions, such as those underlying conservation laws or the impossibility of machines. The theory has been applied to diverse areas, including a constructor-theoretic formulation of information, where is defined as that which can be copied by a constructor, resolving paradoxes in quantum and classical contexts. Extensions include , where principles like the second law emerge from the possibility of certain heat-to-work conversions; the origins of life, by explaining self-reproduction through constructor-like processes; and even time, proposing a theory that derives temporal directionality from transformation possibilities. Ongoing research, supported by institutions like Oxford's Department of Physics and the Templeton World Charity Foundation, continues to explore its implications for , , and the integration of creation into physical laws.

Introduction

Definition and overview

Constructor theory is a proposed framework for reformulating the fundamental laws of physics in terms of which physical transformations, or tasks, are possible and which are impossible, and why they are so, without reference to initial conditions, dynamical equations, or specific trajectories over time. This approach shifts the focus from describing how physical systems evolve to expressing laws as constraints on what can or cannot occur in principle. At its core, constructor theory relies on a fundamental between possible and impossible transformations, independent of , or particular dynamics. These statements are inherently counterfactual, meaning they assert what would happen (or not) under specified conditions, enabling a more general and explanatory formulation of physical principles that applies across diverse domains. By emphasizing tasks—defined as input-output pairs of physical states—the theory aims to unify disparate areas of physics under a common set of principles about feasibility. Proposed by physicist in 2012, constructor theory has been further developed through collaborations, notably with . Central to the theory is the concept of a constructor, a physical system capable of reliably performing a specific transformation on other systems (the substrates) repeatedly without net degradation of its own capacity to do so. For instance, a exemplifies a constructor, as it cyclically converts into work while returning to its initial state, enabling the task without depleting its functionality.

Historical background

Constructor theory originated with David Deutsch's seminal 2012 preprint, later published in 2013, which proposed a new foundational framework for physics centered on the distinction between possible and impossible physical transformations. This work built directly on Deutsch's pioneering contributions to in the 1980s, where he developed the concept of universal quantum computers, and his advocacy for the of , which emphasizes objective reality over probabilistic outcomes. In the 2012 Edge.org conversation, Deutsch described the theory's roots in extending these ideas to generalize all physical processes, motivated by the need to bridge abstract computational principles with concrete physical implementations. The primary intellectual motivation for constructor theory was to reformulate fundamental physics in terms of counterfactual statements about what transformations can or cannot occur, rather than relying solely on dynamical laws that predict trajectories from initial conditions. This approach aimed to unify disparate areas of physics by addressing inherent limitations in standard theories, such as their inability to directly account for irreversibility in or the emergence of complex phenomena like without invoking special initial conditions. Deutsch argued that traditional physics, while predictive, fails to explain why certain processes are possible at all, drawing inspiration from Karl Popper's falsificationism to emphasize explanatory principles over mere computation. From 2013 onward, joined Deutsch in developing and expanding the theory, leading to collaborative papers that applied constructor-theoretic principles to and . Their 2015 joint work on the constructor theory of provided a substrate-independent definition of in terms of possible transformations, resolving long-standing issues in . Key milestones include Marletto's 2015 paper on the constructor theory of life, which demonstrated how self-reproduction and could arise under no-design laws of physics. The theory gained broader attention in 2021 through a Quanta Magazine feature, which highlighted its innovative use of counterfactuals to recast physical laws. In May 2025, Deutsch and Marletto introduced the constructor theory of time, proposing a framework that derives the from the possibilities of physical transformations.

Core Concepts

Constructors

In constructor theory, a constructor is defined as a capable of causing a specified physical transformation—known as a task—from input states to output states, repeatedly and with arbitrary accuracy, without undergoing any net change in its own state or ability to perform that task. This repeatability ensures that the constructor can be used indefinitely for the same transformation, provided it receives any necessary auxiliary inputs, such as , without degrading over time. Key properties of constructors include their stability under the tasks they perform, meaning they must preserve their functionality across repeated applications, and their role in enabling reliable, high-fidelity physical processes. Unlike transient mechanisms that might alter or consume themselves, constructors facilitate the replication of transformations, forming the basis for predictable physical laws. Examples of constructors illustrate this across scales: a classical acts as a constructor by repeatedly transforming blank and an original document into copies, without net degradation if properly maintained; similarly, a serves as a constructor in processing, reliably applying unitary transformations to qubits with near-perfect accuracy. Constructors are the central entities in the theory, with all fundamental laws of physics reformulated as statements about which constructors can or cannot exist in principle, shifting the focus from dynamical evolution to the possibility of such repeatable agents.

Tasks and physical transformations

In constructor theory, a task is defined as an abstract specification of a physical transformation, consisting of a set of input-output pairs of states (or attributes) for a given substrate, without reference to any specific time evolution or causal mechanism. This formulation allows tasks to represent any conceivable change in a physical system, such as altering the configuration of particles or fields, in a manner independent of dynamical laws. A task is deemed possible if there exists a constructor—a physical entity capable of repeatedly and reliably enacting the transformation without degradation—that can perform it with arbitrarily high accuracy, subject only to the laws of physics imposing no fundamental limit short of perfection. Conversely, a task is impossible if no such constructor can exist under the prevailing physical laws, thereby providing a counterfactual criterion for delineating feasible from infeasible transformations. This shifts the focus of physical explanation from what can happen under initial conditions to what must or cannot occur in principle. Tasks exhibit a hierarchical structure through the subtask relation, where complex transformations can be decomposed into simpler subtasks that combine either serially or in parallel. Serial composition, denoted as B∘AB \circ A, involves applying task AA followed by task BB on the output of AA, while parallel composition, A⊗BA \otimes B, entails performing both tasks simultaneously on distinct substrates. This composition enables a modular of physical processes, revealing how intricate phenomena emerge from basic possible tasks without invoking probabilistic or dynamical details. For instance, reversible computation exemplifies a possible task: given a substrate with distinguishable states forming a reversible information-processing medium, a constructor can map any of those states back to itself arbitrarily accurately, preserving all . In contrast, constructing a machine of the first kind—extracting work from a single without net change—is an impossible task, as it would violate the by enabling a constructor to repeatedly convert thermal disorder into ordered motion without compensation.

Fundamental Principles

Constructor-theoretic statements

Constructor theory reformulates the laws of physics as statements about the possibility or impossibility of certain physical transformations, known as tasks. A task is defined as a set of input-output pairs of physical states, and a constructor-theoretic statement asserts whether a constructor—a physical system capable of repeatedly performing a task with arbitrary accuracy without net degradation—exists for a given task or not. These statements take the form of prohibitions, such as "no constructor exists that can perform task XX," or affirmations, such as "a constructor exists for task YY under conditions ZZ." This approach expresses fundamental laws exclusively in terms of what transformations can or cannot occur, independent of specific dynamical equations. One key advantage of this formulation over traditional dynamical theories is that it eliminates the reliance on initial conditions and trajectories, focusing instead on general principles of possibility that apply universally across different scales and substrates. Dynamical laws predict outcomes from specific starting points, but constructor-theoretic statements provide explanatory counterfactuals—asserting why certain changes are impossible—thus revealing deeper invariances without specifying mechanisms. For instance, conservation laws are recast as prohibitions on constructors that could alter conserved quantities, such as the impossibility of a constructor creating from nothing, which corresponds to the prohibition of machines of the first kind. The ultimate goal of constructor theory is to unify all fundamental laws of physics—from to and beyond—in this common language of tasks and constructors, enabling a substrate-independent framework that encompasses classical and quantum regimes alike. By prioritizing what is possible and impossible, these statements aim to derive existing laws and potentially discover new ones, such as those governing and , without presupposing particular physical realizations.

Principle of constructor stability

The principle of constructor stability is a foundational in constructor theory, stipulating that a constructor capable of reliably performing a specified physical transformation—known as a task—must, upon completing the task, remain a constructor for that same task with arbitrarily high probability. This ensures that the constructor undergoes no net degradation in its functionality, allowing it to repeat the task indefinitely without loss of capability, barring imperfections that approach but do not reach zero probability. This underpins the reliability of physical processes in the , preventing the irreversible degradation of constructors and enabling the consistent execution of transformations across multiple instances. It establishes a framework for that is essential for deriving laws of physics from statements about possible and impossible tasks, as unstable constructors would undermine the 's predictive power. Analogous to the unitarity principle in , which preserves the norm of quantum states during , constructor stability provides a more general constraint applicable beyond , ensuring the persistence of transformative abilities in classical and other domains. A representative example is a chemical catalyst, which acts as a stable constructor by facilitating a reaction between substrates while remaining unchanged and capable of catalyzing the same reaction repeatedly. In this case, the task is the transformation of reactants into products, and the catalyst's stability guarantees that it does not consume or alter itself in the process, allowing for efficient, scalable chemical processes. The principle also facilitates fault-tolerant mechanisms, such as error correction in computational and replicative systems, by requiring constructors to maintain integrity against noise or perturbations during task execution. This stability is crucial for enabling robust replication and , as seen in programmable constructors that can correct errors while preserving their ability to perform subtasks reliably.

Role of counterfactuals

In constructor theory, counterfactuals are defined as statements asserting the impossibility of certain physical transformations, even under specified initial conditions that might otherwise suggest their occurrence. For instance, a counterfactual might state that "even if the initial conditions were set up in a particular way, this transformation could not occur," emphasizing prohibitions rooted in fundamental laws. This approach, proposed by , positions counterfactuals as the core language for expressing physical principles, distinguishing them from predictive dynamical equations by focusing on what is categorically forbidden. The explanatory power of counterfactuals lies in their ability to derive physical laws without relying on simulations of dynamical processes or trajectories, instead highlighting why certain outcomes cannot happen. By articulating impossibilities, counterfactuals provide a deeper understanding of physical reality, enabling the formulation of exact principles that capture phenomena elusive to traditional theories, such as the of or . This method shifts the focus from "how" transformations occur to "why" they do not, offering a more fundamental explanatory framework that avoids approximations inherent in dynamical models. A key example is the second law of , reformulated in constructor theory as a counterfactual : no constructor can perform the task of decreasing in an , rendering machines of the second kind impossible. This counterfactual statement derives the law's content precisely, without the coarse-grained statistical approximations typical of conventional , by specifying the task's impossibility in terms of constructor capabilities. Philosophically, counterfactuals in constructor theory draw from Karl Popper's principle of , where the empirical content of scientific theories resides in their prohibitions—what they rule out—rather than mere predictions. Deutsch extends this by arguing that true scientific consists in identifying patterns of possible and impossible transformations, aligning constructor theory with a view of physics as a quest for comprehensive understanding over mere computation.

Formalism and Structure

Mathematical framework

Constructor theory formalizes physical laws through a centered on tasks and constructors, eschewing dynamical equations in favor of statements about possible and impossible transformations. A task TT is a set of input-output pairs on one or more physical substrates, specifying allowable transformations between states. Constructors, denoted CTC_T, are entities or subsystems capable of performing task TT by reliably converting inputs to corresponding outputs, while remaining available for repeated use. A task TT is possible, written T✓T \checkmark, if there exists a constructor CTC_T such that the task can be performed repeatedly with arbitrary accuracy short of perfection under the laws of physics. Conversely, a task is impossible, written T×T \times, if it is forbidden by the laws of physics, meaning no constructor can perform it with arbitrary accuracy. This formulation accounts for the inherent limitations in physical processes while emphasizing reliable repeatability as the hallmark of possibility. Central to the theory is the principle of constructor stability, which ensures that performing a task causes no net change in the constructor's ability to perform that task. This stability underpins the theory's focus on resilient transformations, distinguishing constructors from transient processes.

Subtasks and composition rules

In constructor theory, tasks can be decomposed into networks of subtasks, allowing hierarchical analysis of complex physical processes by breaking them down into elementary, composable units, where each subtask is defined as a set of input-output state pairs on specified substrates. Composition of tasks occurs through parallel and serial mechanisms. In parallel composition, denoted T1⊗T2T_1 \otimes T_2, two independent subtasks T1T_1 and T2T_2 are performed simultaneously on separate substrates, yielding a combined task that achieves both effects without interference. Serial composition sequences subtasks such that the outputs of the first match the inputs of the second, forming a chain where the overall task transforms initial inputs through successive steps. A constructor for the composite task exists if constructors for the individual subtasks can be combined, provided the network of subtasks is regular—meaning outputs connect properly to inputs without cycles or incompatibilities. The fundamental rule governing composition is the composition principle, which states that any regular network of possible tasks is itself possible, implying that the set of possible tasks is closed under composition, without exceptions imposed by underlying physical laws unless explicitly forbidden. An illustrative example is the copying of , which can be analyzed as a network involving a subtask (distinguishing the state without perturbation) and a replication subtask (imprinting the state onto a blank medium). Here, the outputs of measurement serve as inputs to replication, resulting in an overall task that produces two identical copies from one original and a blank, possible only if the media support the required as per constructor-theoretic principles of information media.

Applications

Thermodynamics and information theory

Constructor theory provides a novel framework for deriving the fundamental by focusing on the possible and impossible physical transformations, or tasks, that constructors—repeatable physical processes—can perform. The second law of thermodynamics emerges as the principle that no constructor exists capable of decreasing the total of an , formalized through the concept of adiabatic inaccessibility: tasks that reduce cannot occur without side-effects on auxiliary systems beyond work media. This prohibition ensures that entropy-increasing processes are possible, while the reverse is impossible, aligning with the interpretation but expressed purely in terms of task possibilities. The first law of follows from the constructor-theoretic principle of , which prohibits tasks that alter the of a without corresponding changes in work or media. Specifically, work media are defined such that transfers between them are interoperable and conserved, preventing perpetual motion machines of the first kind by ruling out tasks like extracting work without input. This formulation unifies the law across scales, from microscopic to macroscopic systems, without relying on initial conditions or dynamical laws. Building on these thermodynamic foundations, the constructor theory of information redefines in a substrate-independent manner, treating it as a physical entity characterized by the possibility of specific tasks like and erasing, rather than probabilistic or dynamical descriptions. Introduced by Deutsch and Marletto, this theory posits that a carries if a constructor can reliably perform the task—transforming an input pair (blank state, informed state) into two copies of the informed state—across arbitrary substrates, such as bits or physical particles. Erasure, the complementary task, resets an informed state to a standard blank state and is inextricably linked to thermodynamic costs. A pivotal result in this theory is the generalization of the no-cloning theorem, which demonstrates that cloning tasks are impossible for non-classical forms of information, thereby distinguishing classical information—defined by sharp, clonable variables—from quantum information, where superposition and entanglement render cloning tasks prohibited due to overlapping state attributes. Classical information allows perfect copying without disturbance, while quantum information's non-clonability arises from the impossibility of distinguishing certain attributes without measurement, preserving foundational differences between the two without substrate-specific assumptions. The erasure task exemplifies the thermodynamic-information interplay: E={(mx,w)→(mˉ,w′)∣x∈X}E = \{ (m_x, w) \to (\bar{m}, w') \mid x \in X \} where mxm_x denotes a substrate state encoding information xx from a set XX, mˉ\bar{m} is the standard blank state, ww is the initial work medium state, and w′w' is the final state with increased entropy (dissipated work). This task is possible only with a net work input, whose minimum cost corresponds to Landauer's principle, ensuring that erasing one bit of information dissipates at least kTln⁡2kT \ln 2 energy as heat in a thermal bath at temperature TT, thus deriving information-thermodynamic limits from constructor principles alone.

Quantum mechanics and extensions

In constructor theory, is reformulated through the lens of quantum constructors, which are idealized devices capable of repeatedly implementing unitary operations on with arbitrarily high accuracy and reliability while remaining unchanged themselves. These constructors embody the principle that the possible tasks in quantum physics are precisely those achievable via such unitary transformations, excluding impossible ones like non-unitary evolutions. This framework derives fundamental quantum theorems directly from the dichotomy of possible and impossible tasks, without relying on probabilistic interpretations or initial conditions. A key application is the treatment of quantum information as "superinformation," a substrate where certain tasks, such as perfect cloning or deletion, are impossible due to the non-distinguishability of states. The emerges because no constructor can reliably perform the task of duplicating an unknown onto a blank one, as this would require distinguishing superposed states in a way incompatible with unitary stability. Similarly, the follows from the impossibility of selectively erasing one instance of a quantum state while preserving another, preserving the intrinsic correlations in . These derivations highlight how constructor theory unifies quantum restrictions under general principles of task possibility. Entanglement and superposition are characterized as possible tasks facilitated by quantum constructors, allowing transformations that exploit non-local correlations and linear superpositions. For instance, creating entangled states from product states or evolving superpositions under unitary dynamics enables computational tasks impossible in , such as factoring efficiently via quantum algorithms. This provides a constructor-theoretic explanation for quantum computational advantages, rooted in the stability of unitary constructors rather than specific hardware implementations. Constructor theory extends beyond standard by addressing emergent phenomena, such as time. In a recent formulation, time is posited as arising from the possible temporal transformations that constructors can perform, rendering it an emergent property rather than a fundamental parameter in physical laws. This approach aligns with unitary quantum theory while avoiding references to absolute time in the foundational principles. Constructor theory has also been applied to and hybrid systems, where it provides principles for interactions between quantum and classical or systems without relying on specific dynamical laws. For example, it supports proposals for experiments to detect quantum effects in , such as gravitationally induced entanglement between massive particles in superposition, using the principles of locality and interoperability to make scale-independent predictions. These applications aim to resolve challenges in unifying with . As an illustrative example, demonstrates the stability of quantum constructors against decoherence. By encoding logical qubits across multiple physical qubits and using syndrome measurements, error-correcting codes enable constructors to repeatedly apply unitary operations despite , maintaining the possibility of coherent quantum tasks over extended durations. This aligns with the principle of constructor stability, where auxiliary systems facilitate reliable transformations in noisy regimes.

Biology and life

Constructor theory provides a framework for understanding as a set of possible constructor tasks involving replication, variation, and , without requiring biological adaptations to be encoded directly in the laws of physics. In this view, emerges from self-reproduction and under "no-design" laws—fundamental physical principles that do not presuppose any specific biological outcomes. The theory posits that these processes are feasible if the laws permit digital information to be physically instantiated, allowing for the blind copying of modular templates. Central to this approach are replicators, which function as constructors capable of copying themselves with high fidelity. A replicator, such as a gene or DNA sequence, acts as a template that blindly replicates, but it requires a "vehicle"—a supporting structure like cellular machinery—to achieve accurate self-reproduction and form a complete self-reproducer. Evolution proceeds through variation introduced by mutations that are possible under the laws of physics, with natural selection favoring those that enhance replication success in the environment. This mechanism enables the emergence of complex, design-like adaptations without fine-tuning the laws themselves, distinguishing living systems from non-living ones by their capacity to perform these specific constructor tasks reliably. For instance, DNA replication exemplifies a stable constructor task in biological systems. Here, DNA serves as the replicator template, while enzymes and other cellular components act as the vehicle to copy the sequence accurately and assemble new cells, thereby enabling heredity and the perpetuation of genetic information across generations. This task's stability under constructor theory underscores how life's metabolic and reproductive processes can arise from generic physical resources, provided the laws support the necessary information-handling capabilities.

Criticisms and Future Directions

Key criticisms

Constructor theory has faced philosophical criticisms for appearing tautological, essentially rephrasing established physical laws in terms of possible and impossible tasks rather than generating novel predictions or incorporating dynamical content about how physical systems evolve over time. This perspective suggests that the theory's principles, while elegant, may not advance beyond descriptive reformulations of existing knowledge, potentially limiting its explanatory power in addressing unresolved problems in physics. From a scientific standpoint, detractors argue that constructor theory remains not fully falsifiable in the Popperian sense, as its statements about tasks do not yet provide clear pathways to derive the standard dynamical equations of physics, such as those in or , making empirical testing challenging. The framework's reliance on abstract principles of possibility and impossibility is seen as insufficient for yielding precise, quantitative predictions that can be directly confronted with experimental data, thereby hindering its integration into mainstream . Adoption within the physics community has been limited as of 2025, with seminal papers on the theory accumulating only around 190 citations for key works like the constructor theory of , indicating modest impact compared to high-profile developments in the field. Many physicists view it as speculative, despite its proposed applications, due to the absence of widespread mathematical formalization and experimental validation that would encourage broader engagement. A 2021 discussion in Quanta Magazine underscored critiques regarding the theory's heavy dependence on counterfactuals—statements about what could or could not happen—potentially without introducing sufficient empirical novelty to distinguish it from conventional physical theories. This overemphasis on hypothetical possibilities is argued to prioritize conceptual reframing over testable advancements, reinforcing perceptions of the theory as more philosophical than rigorously scientific.

Recent developments

In 2023 and 2024, constructor theory has been extended to analyze hybrid classical-quantum systems, particularly to probe inconsistencies in models involving . A key contribution came from Feng, Marletto, and Vedral, who applied constructor-theoretic principles to conservation laws, demonstrating that classical cannot modify quantum or , thereby supporting the need for gravity's quantization in such hybrid frameworks to avoid dynamical contradictions. These developments have implications for information processing in mixed systems, building on earlier constructor theory of information to address challenges in quantum-classical interfaces. In May 2025, Chiara Marletto advanced the theory with "Constructor theory of time," formulating time as emergent from possible temporal constructors—cyclic physical devices capable of repeatedly implementing specific transformations—while keeping fundamental laws timeless to evade paradoxes associated with time's arrow and relativity. This work reconciles constructor theory's atemporal principles with observed dynamics, such as durations and change rates, and maintains compatibility with standard physical laws. In March 2025, Marletto and Vlatko Vedral published a comprehensive review in Reviews of Modern Physics on quantum-information methods for laboratory-based tests of , outlining proposals to detect gravitational entanglement and emphasizing information-theoretic principles that align with constructor theory's focus on possible transformations in hybrid systems. Ongoing research reflects growing interest in constructor-based explanations for in complex systems, including how irreversible processes and higher-level laws arise from possible tasks in and . In October 2025, the Conjecture Institute announced funding support for Marletto's constructor theory research at the , bolstering efforts to develop its applications. Looking ahead, constructor theory holds theoretical potential for unifying with through hybrid system tests and for informing theories of via information and life principles, though these remain speculative and untested.
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