I show how the quantum paradoxes occurring when we adopt a standard realist framework (or a framework in which the collapse implies a physical change of the state of the system) vanish if we abandon the idea that a measurement is related (directly or indirectly) to a physical change of state. In Convivial Solipsism, similarly to Everett interpretation, there is no collapse of the wave function. But contrary to Everett interpretation, there is only one world. This allows also to get rid of any non-locality and to provide a solution to the Wigner friend problem and its more recent versions.I show how the quantum paradoxes occurring when we adopt a standard realist framework (or a framework in which the collapse implies a physical change of the state of the system) vanish if we abandon the idea that a measurement is related (directly or indirectly) to a physical change of state. In Convivial Solipsism, similarly to Everett interpretation, there is no collapse of the wave function. But contrary to Everett interpretation, there is only one world. This allows also to get rid of any non-locality and to provide a solution to the Wigner friend problem and its more recent versions.

arXiv:2301.07532Jan 16, 20230 citations

Nonlocality versus Modified Realism: Convivial Solipsism

Hervé Zwirn C

A large number of physicists now admit that quantum mechanics is a non-local theory. EPR argument and the many experiences (including recent “loop-hole free” tests) showing the violation of Bell’s inequalities seem to have confirmed convincingly that quantum mechanics cannot be local. Nevertheless, this conclusion can only be drawn inside a standard realist framework assuming an ontic interpretation of the wave function and viewing the collapse of the wave function as a real change of the physical state of the system. We show that this standpoint is not mandatory and that if the collapse is no more considered as an actual physical change, it is possible to recover locality.A large number of physicists now admit that quantum mechanics is a non-local theory. EPR argument and the many experiences (including recent “loop-hole free” tests) showing the violation of Bell’s inequalities seem to have confirmed convincingly that quantum mechanics cannot be local. Nevertheless, this conclusion can only be drawn inside a standard realist framework assuming an ontic interpretation of the wave function and viewing the collapse of the wave function as a real change of the physical state of the system. We show that this standpoint is not mandatory and that if the collapse is no more considered as an actual physical change, it is possible to recover locality.

Dec 18, 20182 citations

The measurement problem in Quantum Mechanics: Convivial Solipsism

Hervé Zwirn C

The problem of measurement is often considered an inconsistency inside the quantum formalism. Many attempts to solve (or to dissolve) it have been made since the inception of quantum mechanics. The form of these attempts depends on the philosophical position that their authors endorse. I will review some of them and analyze their relevance. In this paper, I defend a new position, the “Convivial Solipsism”, according to which the outcome that is observed is relative to the observer, different but in close parallel to the Everett’s interpretation and sharing also some similarities with Rovelli’s relational interpretation and Quantum Bayesianism. I also show how “Convivial Solipsism” can help getting a new standpoint about the EPR paradox providing a way out of the seemingly unavoidable non-locality of quantum mechanics.The problem of measurement is often considered an inconsistency inside the quantum formalism. Many attempts to solve (or to dissolve) it have been made since the inception of quantum mechanics. The form of these attempts depends on the philosophical position that their authors endorse. I will review some of them and analyze their relevance. In this paper, I defend a new position, the “Convivial Solipsism”, according to which the outcome that is observed is relative to the observer, different but in close parallel to the Everett’s interpretation and sharing also some similarities with Rovelli’s relational interpretation and Quantum Bayesianism. I also show how “Convivial Solipsism” can help getting a new standpoint about the EPR paradox providing a way out of the seemingly unavoidable non-locality of quantum mechanics.

EPJ Web of ConferencesJan 1, 20200 citations

Wigner's Friend Paradox Revisited

Peter Reichert, Markus Enz

By assuming (i) a universal, observer-independent quantum state, by considering (ii) measurement processes with wave function collapse as part of quantum mechanical time evolution (also within isolated systems), and by (iii) clearly distinguishing the state of a quantum system from the knowledge of conscious observers about this state, we suggest a modified Copenhagen interpretation of quantum mechanics that resolves Wigner's Friend and extended Wigner's Friend paradoxes. The suggested interpretation leads to differences in some outcome probabilities compared to previous analyses which, in principle, make it possible to falsify the suggested modifications or the previous analyses (or both). The fundamental problem of the incompleteness of quantum mechanics in the Copenhagen interpretation regarding the lack of a precise definition and a mechanistic description of the measurement process (including the collapse of the wave function) is not addressed in this study. However, the argumentation regarding the resolution of Wigner's Friend paradoxes also applies to attempts for such a mechanistic description using collapse models with stochastic extensions to the Schrödinger equation or trying to model wave function collapse with unitary time evolution and irreversibility of the measurement process resulting from quantum statistical mechanics.By assuming (i) a universal, observer-independent quantum state, by considering (ii) measurement processes with wave function collapse as part of quantum mechanical time evolution (also within isolated systems), and by (iii) clearly distinguishing the state of a quantum system from the knowledge of conscious observers about this state, we suggest a modified Copenhagen interpretation of quantum mechanics that resolves Wigner's Friend and extended Wigner's Friend paradoxes. The suggested interpretation leads to differences in some outcome probabilities compared to previous analyses which, in principle, make it possible to falsify the suggested modifications or the previous analyses (or both). The fundamental problem of the incompleteness of quantum mechanics in the Copenhagen interpretation regarding the lack of a precise definition and a mechanistic description of the measurement process (including the collapse of the wave function) is not addressed in this study. However, the argumentation regarding the resolution of Wigner's Friend paradoxes also applies to attempts for such a mechanistic description using collapse models with stochastic extensions to the Schrödinger equation or trying to model wave function collapse with unitary time evolution and irreversibility of the measurement process resulting from quantum statistical mechanics.

quant-pharXiv:2608.02635Aug 3, 20260 citations

Non Locality versus Modified Realism: Convivial Solipsism

Hervé Zwirn C

A large number of physicists now admit that quantum mechanics is a non local theory. The EPR argument and the many experiments (including recent loop-hole free tests) showing the violation of Bell's inequalities seem to have confirmed convincingly that quantum mechanics cannot be local. Nevertheless, this conclusion can only be drawn inside a standard realist framework assuming an ontic interpretation of the wave function and viewing the collapse of the wave function as a real change in the physical state of the system. We show that this standpoint is not mandatory and that if the collapse is not considered an actual physical change, it is possible to recover locality.A large number of physicists now admit that quantum mechanics is a non local theory. The EPR argument and the many experiments (including recent loop-hole free tests) showing the violation of Bell's inequalities seem to have confirmed convincingly that quantum mechanics cannot be local. Nevertheless, this conclusion can only be drawn inside a standard realist framework assuming an ontic interpretation of the wave function and viewing the collapse of the wave function as a real change in the physical state of the system. We show that this standpoint is not mandatory and that if the collapse is not considered an actual physical change, it is possible to recover locality.

arXiv:1812.06451Dec 16, 20180 citations

On the Tangled Hierarchy of Wave Functions and Observers

Matej Pavšič

This paper explores the intricate relationship between the observer, consciousness, and quantum mechanics, attempting to defend the interpretation of the wave function as a representation of consciousness. More precisely, in our framework, a quantum state, represented by a wave function, determines a state of consciousness related to the first-person experiences, $w$ , of the events $E$ , detected by senses. Building on Everett’s many-worlds interpretation, we argue that the wave function is not an objective universal entity, but rather one that is inherently associated with the first-person experiences $w \in P$ of an observer $\mathcal{O}$ . The set $P$ also includes other observers, $\mathcal{O}^{\prime}$ , as subsets. We demonstrate that this proposal does not lead to solipsism, because there is no unique hierarchy of observers, as indicated above, but there are many possible hierarchies of observers, such that, e.g., the roles of the first-person observer, $\mathcal{O}$ , and the third-person observer, $\mathcal{O}^{\prime}$ are interchanged. The corresponding quantum states, $\psi_{\mathcal{O}}$ and $\psi_{\mathcal{O}^{\prime}}$ , are elements of the space of all possible quantum states, the Hilbert space, $\mathcal{H}$ . It is this larger space that we identify as the objective reality. Thus, our approach overcomes the main obstacle faced by researchers who tried to make sense of quantum mechanics, namely, the wall of solipsism. In this framework, the Everett many-worlds interpretation and the wave function collapse interpretation are not mutually exclusive but instead represent complementary perspectives within the hierarchy of observers, each offering insight into the underlying physics from a different vantage point.This paper explores the intricate relationship between the observer, consciousness, and quantum mechanics, attempting to defend the interpretation of the wave function as a representation of consciousness. More precisely, in our framework, a quantum state, represented by a wave function, determines a state of consciousness related to the first-person experiences, $w$, of the events $E$, detected by senses. Building on Everett’s many-worlds interpretation, we argue that the wave function is not an objective universal entity, but rather one that is inherently associated with the first-person experiences $w \in P$ of an observer $\mathcal{O}$ . The set $P$ also includes other observers, $\mathcal{O}^{\prime}$, as subsets. We demonstrate that this proposal does not lead to solipsism, because there is no unique hierarchy of observers, as indicated above, but there are many possible hierarchies of observers, such that, e.g., the roles of the first-person observer, $\mathcal{O}$, and the third-person observer, $\mathcal{O}^{\prime}$ are interchanged. The corresponding quantum states, $\psi_{\mathcal{O}}$ and $\psi_{\mathcal{O}^{\prime}}$, are elements of the space of all possible quantum states, the Hilbert space, $\mathcal{H}$. It is this larger space that we identify as the objective reality. Thus, our approach overcomes the main obstacle faced by researchers who tried to make sense of quantum mechanics, namely, the wall of solipsism. In this framework, the Everett many-worlds interpretation and the wave function collapse interpretation are not mutually exclusive but instead represent complementary perspectives within the hierarchy of observers, each offering insight into the underlying physics from a different vantage point.

QeiosMar 30, 20250 citations

w

, of the events

E

, detected by senses. Building on Everett’s many-worlds interpretation, we argue that the wave function is not an objective universal entity, but rather one that is inherently associated with the first-person experiences

w \in P

of an observer

\mathcal{O}

. The set

P

also includes other observers,

\mathcal{O}^{\prime}

, as subsets. We demonstrate that this proposal does not lead to solipsism, because there is no unique hierarchy of observers, as indicated above, but there are many possible hierarchies of observers, such that, e.g., the roles of the first-person observer,

\mathcal{O}

, and the third-person observer,

\mathcal{O}^{\prime}

are interchanged. The corresponding quantum states,

\psi_{\mathcal{O}}

and

\psi_{\mathcal{O}^{\prime}}

, are elements of the space of all possible quantum states, the Hilbert space,

\mathcal{H}

. It is this larger space that we identify as the objective reality. Thus, our approach overcomes the main obstacle faced by researchers who tried to make sense of quantum mechanics, namely, the wall of solipsism. In this framework, the Everett many-worlds interpretation and the wave function collapse interpretation are not mutually exclusive but instead represent complementary perspectives within the hierarchy of observers, each offering insight into the underlying physics from a different vantage point.