J. Rogers, SE Ohio
Abstract
Classical and early quantum physics rely heavily on the "Newtonian paradigm," which segments the universe into an isolated physical system (the "box") and an external observer or environment[1]. While this methodology serves as a highly successful approximation for local experiments, this paper argues that truly isolated systems do not exist within a unified, relational universe[1]. Drawing from Relational Quantum Mechanics (RQM)[2][3], Smolin’s critique of the cosmological fallacy[1], and Teller’s relational holism[4], we demonstrate that physical properties (such as mass, charge, and position) are fundamentally relational, emerging only through mutual interaction rather than existing as intrinsic, state-dependent attributes of isolated objects[5][6]. Furthermore, because of causal delay and the porous nature of boundary conditions, we show that any attempt to describe a local subsystem with absolute precision requires modeling the entire, self-interacting cosmic network. We conclude that the isolated system is an artifact of mathematical compression (the "map") rather than a feature of objective physical reality (the "territory").
1. Introduction: The Truncation of Nature
The historic success of physics rests upon a foundational simplification: the isolation of the subject. To study a physical process, the experimentalist draws a boundary around a subset of the universe, ignoring the rest of the cosmos as background noise or static boundary conditions[1]. This process—what Smolin refers to as the "Newtonian paradigm"—divides the world into "the system" and "the observer/apparatus"[1][7].
This methodology is an intentional truncation of nature[1]. While highly pragmatic, it introduces a deep conceptual bias: it treats the "isolated system" as a fundamentally existing entity[7]. In a unified universe governed by relational laws, this isolation is a physical impossibility. There is no background spacetime to act as a passive stage, and there are no impenetrable walls that can completely decouple a local region of space from the ongoing self-interactions of the rest of the cosmos[8][9]. This paper formalizes why the concept of an isolated system is physically and philosophically incoherent in a truly relational universe.
2. The Cosmological Fallacy and the "Box" Paradigm
In local experimental physics, the rest of the universe is implicitly present to supply the rules, rulers, and clocks that define the coordinates of the isolated system[1]. However, taking the laws formulated for these small, isolated "boxes" and applying them to the universe as a whole commits what is known as the cosmological fallacy[1].
As Smolin argues, a cosmological theory cannot rely on an external background because there is nothing outside the universe to provide reference frames, clocks, or initial parameters[1][10].
This realization yields a fundamental cosmological principle: the principle of no isolated systems[1][7]. In a universe that is a closed, self-contained system, every subsystem is constantly subject to external, non-zero causal influences from the rest of the cosmos[1][7]. The idealization of an isolated system relies on a "view from nowhere"—an absolute, external reference frame that special and general relativity have systematically dismantled[10].
3. Relational Quantum Mechanics and the Relata of Interaction
The non-existence of isolated systems is most sharply illustrated by the ontology of Relational Quantum Mechanics (RQM), originally proposed by Carlo Rovelli[2][3].
In classical mechanics, one could comfortably imagine a particle existing in a vacuum, possessing a definite position, momentum, and mass "to itself". RQM, however, asserts that physical variables do not attain concrete values until two systems interact[11]. Moreover, these values are strictly relational; they have meaning only with respect to the specific systems involved in the interaction[10][11].
Within RQM:
No Absolute States: Attributing an absolute, objective quantum state to an isolated, non-interacting system is physically meaningless[3][12].
Interaction as Ontology: The physical world is not a collection of self-existing objects, but a web of interaction events[10][13]. A system is defined entirely by the relations it entertains with surrounding systems[3].
The Non-Separability of the Observer: If System
S
is observed by Observer A
, the state of S
acquires definiteness only relative to A
[10]. For an external Observer B
, the combined system (S+A
) remains in a coherent superposition until B
interacts with them[14].
There is no consistent way to assign a pure state to a single, isolated system if it has ever interacted with any other system—and in practice, nothing is ever completely isolated[10]. Therefore, RQM forces us to abandon the concept of "things-in-themselves" in favor of "relations before things"[10].
4. Relational Holism and Causal Interconnectedness
The relational nature of the universe is further supported by the concept of relational holism, formalised by philosopher Paul Teller[4]. Relational holism posits that there are physical relations between entities that do not supervene on the qualitative, intrinsic properties of the individual components[4].
In quantum mechanics, this is exemplified by entanglement[4]. When two particles interact and become entangled, their joint state cannot be factorized into individual, independent states[4]. They can no longer be described as two isolated systems, even if they are separated by astronomical distances[4].
Furthermore, this relational connectivity is bound by the structure of causality:
The state of any local system
A
at time t
is the summation of causal influences propagating from its past light cone.This past light cone contains the historical, evolving interactions of the entire universe.
Because forces (such as gravity and electromagnetism) have infinite range and propagate at a finite speed (
c
), the relational state of any local system is constantly being updated by delayed signals from the rest of the cosmos.
To treat a local system as "isolated" requires assuming that these incoming causal signals can be completely blocked or neutralized—an assumption that violates the basic principles of field theories and gravity.
5. The Limit of Infinite Precision: The Map vs. The Territory
If we attempt to model a subsystem of
N
particles with perfect, exact precision, the fallacy of isolation becomes mathematically apparent.In a classical map, we write down the coordinates of
N
particles and treat the outside universe as a static set of boundary conditions. However, because the boundary of our "box" is porous to gravitational and electromagnetic radiation, these boundary conditions are constantly changing.To maintain perfect precision, our model of the
N
particles must account for every external perturbation. But these external perturbations are themselves caused by other particles. To predict how those external influences will evolve, we must expand our model to include those external particles. This expansion cascade continues outward until the model must encompass every particle in the universe and their evolving interactions.The implication is profound:
The only perfect model of any subsystem is a model of the entire universe.
The local cannot be decoupled from the global without introducing approximation (compression).
The concept of an "isolated system" is not a physical reality; it is a mathematical tool—a necessary compression that allows human observers to map a highly simplified version of the territory.
8. Conclusion: The Unified Whole
The historical division of the world into isolated systems, backgrounds, and observers was a necessary scaffolding for the development of classical physics[1]. However, as our understanding has progressed through general relativity, quantum mechanics, and relational theories, this scaffolding has revealed its limitations[1].
There are no isolated systems in a unified universe[1][7]. The properties we attribute to individual objects—position, velocity, mass, and even time—are emergent properties of the global, self-interacting causal network[8][11]. Spacetime is not an empty box containing isolated actors; it is the macroscopic shape of their mutual relationships[8].
Acknowledging the non-existence of isolated systems allows us to move past the cosmological fallacy and towards a truly background-independent, relational physics[1]—one where the universe is understood not as a collection of separate building blocks, but as an undivided, self-interacting whole[8].
Grounding References
[1] Relational Quantum Mechanics (RQM)
Rovelli, C. (1996). Relational Quantum Mechanics. International Journal of Theoretical Physics, 35, 1637-1678. arXiv:quant-ph/9609002.
Application: Provides the mathematical and conceptual foundation for Section 3, establishing that quantum states are not intrinsic properties of isolated systems but relational values arising strictly from pairwise interactions[3][11].
Laudisa, F., & Rovelli, C. (2021). Relational Quantum Mechanics. Stanford Encyclopedia of Philosophy. Link.
Application: Elaborates on the ontology of RQM as an "ontology of events-of-interaction, not of objects-in-isolation"[10], verifying that assigning an absolute state to an isolated system is physically incoherent[10].
[2] The Principle of No Isolated Systems & The Cosmological Fallacy
Smolin, L. (2013). Time Reborn: From the Crisis in Physics to the Future of the Universe. Houghton Mifflin Harcourt.
Application: Directly grounds Section 2 and 5. Smolin defines the "cosmological fallacy"[1] and outlines the "principle of no isolated systems"[1][7], demonstrating that taking the physics designed for small, isolated subsystems and applying it to the universe as a whole is a fundamental category error[1].
[3] Relational Holism and Non-Separability
Teller, P. (1986). Relational Holism and Quantum Mechanics. The British Journal for the Philosophy of Science, 37(1), 71-81.
Application: Grounds Section 4. Teller introduces "relational holism"[4], explaining how entangled physical systems possess mutual, non-supervening relations that cannot be reduced to the qualitative intrinsic properties of individual, isolated components[4].
