Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

A simple proof that the many-worlds interpretation of quantum mechanics is inconsistent

Shan Gao

Published Dec 26, 2018• 0 citations
OpenAlex

Abstract

The many-worlds interpretation of quantum mechanics is based on three key assumptions: (1) the completeness of the physical description by means of the wave function, (2) the linearity of the dynamics for the wave function, and (3) multiplicity. In this paper, I argue that the combination of these assumptions may lead to a contradiction. In order to avoid the contradiction, we must drop one of these key assumptions.

Related papers

A thought experiment in many worlds

Shan Gao

The many-worlds interpretation of quantum mechanics (MWI) is based on three key assumptions: (1) the completeness of the physical description by means of the wave function, (2) the linearity of the dynamics for the wave function, and (3) multiplicity. In this paper, I propose a new thought experiment in which a post-measurement superposition undergoes no net change while individual branches do change under certain unitary time evolution. Moreover, I argue that MWI gives contradictory predictions for this experiment. In order to avoid the contradiction and save many worlds, it seems that we must drop one or both of the first two assumptions.

•Feb 19, 2020•0 citations

Ontology of the Wave Function and the Many-Worlds Interpretation

Lev Vaidman A

It is argued that the many-worlds interpretation is by far the best interpretation of quantum mechanics. The key points of this view are viewing the wave functions of worlds in three dimensions and understanding probability through self-locating uncertainty.

Cambridge University Press eBooks•Apr 11, 2019•11 citations

Why the Many-Worlds Interpretation?

Lev Vaidman A

A brief (subjective) description of the state of the art of the many-worlds interpretation of quantum mechanics (MWI) is presented. It is argued that the MWI is the only interpretation which removes action at a distance and randomness from quantum theory. Limitations of the MWI regarding questions of probability which can be legitimately asked are specified. The ontological picture of the MWI as a theory of the universal wave function decomposed into a superposition of world wave functions, the important parts of which are defined in three-dimensional space, is presented from the point of view of our particular branch. Some speculations about misconceptions, which apparently prevent the MWI from being in the consensus, are mentioned.

arXiv:2208.04618•Quantum Reports•Aug 4, 2022•22 citations

The Many-Worlds Interpretation of Quantum Mechanics

Lev Vaidman

Next year, there will be a 100-year celebration of quantum mechanics, but there is no consensus on the interpretation of this theory. This reprint presents recent works on one of the most intriguing interpretations, the many-worlds interpretation, presented at a workshop in October 2022 at Tel Aviv University. The many-worlds interpretation solves the measurement problem, avoids action at a distance and indeterminism, and does not contradict empirical evidence. The main question discussed in the workshop was as follows: why is it not in the consensus? Major issues such as preferred basis, the meaning of probability, non-locality, and alternative approaches were discussed, which are increasingly drawing attention in physics and philosophy. The contributions demonstrated a striking diversity in understanding the basic concepts. What are the worlds in the many-worlds interpretation? Do the worlds diverge or split? Is probability objective or subjective, or is it just an illusion? Can we avoid the non-separability of quantum mechanics? Many questions were raised and significant progress in understanding was achieved, but the papers showed that consensus is still far away. This reprint describes the current status of the research and will be invaluable for physicists and philosophers who want to resolve the long-standing problem of the interpretation of quantum mechanics.

MDPI eBooks•May 11, 2024•14 citations

Are there many worlds

Shan Gao

It is argued that if the wave function represents the complete physical state and its dynamics is linear, then there are no many worlds.

•May 29, 2019•0 citations

- Many-Worlds or Collapse of the Wave-Function? -

Tejinder P. Singh

At present, there are two possible, and equally plausible, explanations for the physics of quantum measurement. The first explanation, known as the many-worlds interpretation, does not require any modification of quantum mechanics, and asserts that at the time of measurement the Universe splits into many branches, one branch for every possible alternative. The various branches do not interfere with each other because of decoherence, thus providing a picture broadly consistent with the observed Universe. The second explanation, which requires quantum mechanics to be modified from its presently known form, is that at the time of measurement the wave-function collapses into one of the possible alternatives. The two explanations are mutually exclusive, and up until now, no theoretical reasoning has been put forward to choose one explanation over the other. In this article, we provide an argument which implies that the collapse interpretation is favored over the many-worlds interpretation. Our starting point is the assertion (which we justify) that there ought to exist a reformulation of quantum mechanics which does not refer to a classical spacetime manifold. The need for such a reformulation implies that quantum theory becomes non-linear on the Planck mass/energy scale. Standard linear quantum mechanics is an approximation to this non-linear theory, valid at energy scales much smaller than the Planck scale. Using ideas based on noncommutative | >=

•Jan 1, 2007•0 citations
The many-worlds interpretation of quantum mechanics is based on three key assumptions: (1) the completeness of the physical description by means of the wave function, (2) the linearity of the dynamics for the wave function, and (3) multiplicity. In this paper, I argue that the combination of these assumptions may lead to a contradiction. In order to avoid the contradiction, we must drop one of these key assumptions.
The many-worlds interpretation of quantum mechanics (MWI) is based on three key assumptions: (1) the completeness of the physical description by means of the wave function, (2) the linearity of the dynamics for the wave function, and (3) multiplicity. In this paper, I propose a new thought experiment in which a post-measurement superposition undergoes no net change while individual branches do change under certain unitary time evolution. Moreover, I argue that MWI gives contradictory predictions for this experiment. In order to avoid the contradiction and save many worlds, it seems that we must drop one or both of the first two assumptions.
A brief (subjective) description of the state of the art of the many-worlds interpretation of quantum mechanics (MWI) is presented. It is argued that the MWI is the only interpretation which removes action at a distance and randomness from quantum theory. Limitations of the MWI regarding questions of probability which can be legitimately asked are specified. The ontological picture of the MWI as a theory of the universal wave function decomposed into a superposition of world wave functions, the important parts of which are defined in three-dimensional space, is presented from the point of view of our particular branch. Some speculations about misconceptions, which apparently prevent the MWI from being in the consensus, are mentioned.
Next year, there will be a 100-year celebration of quantum mechanics, but there is no consensus on the interpretation of this theory. This reprint presents recent works on one of the most intriguing interpretations, the many-worlds interpretation, presented at a workshop in October 2022 at Tel Aviv University. The many-worlds interpretation solves the measurement problem, avoids action at a distance and indeterminism, and does not contradict empirical evidence. The main question discussed in the workshop was as follows: why is it not in the consensus? Major issues such as preferred basis, the meaning of probability, non-locality, and alternative approaches were discussed, which are increasingly drawing attention in physics and philosophy. The contributions demonstrated a striking diversity in understanding the basic concepts. What are the worlds in the many-worlds interpretation? Do the worlds diverge or split? Is probability objective or subjective, or is it just an illusion? Can we avoid the non-separability of quantum mechanics? Many questions were raised and significant progress in understanding was achieved, but the papers showed that consensus is still far away. This reprint describes the current status of the research and will be invaluable for physicists and philosophers who want to resolve the long-standing problem of the interpretation of quantum mechanics.
At present, there are two possible, and equally plausible, explanations for the physics of quantum measurement. The first explanation, known as the many-worlds interpretation, does not require any modification of quantum mechanics, and asserts that at the time of measurement the Universe splits into many branches, one branch for every possible alternative. The various branches do not interfere with each other because of decoherence, thus providing a picture broadly consistent with the observed Universe. The second explanation, which requires quantum mechanics to be modified from its presently known form, is that at the time of measurement the wave-function collapses into one of the possible alternatives. The two explanations are mutually exclusive, and up until now, no theoretical reasoning has been put forward to choose one explanation over the other. In this article, we provide an argument which implies that the collapse interpretation is favored over the many-worlds interpretation. Our starting point is the assertion (which we justify) that there ought to exist a reformulation of quantum mechanics which does not refer to a classical spacetime manifold. The need for such a reformulation implies that quantum theory becomes non-linear on the Planck mass/energy scale. Standard linear quantum mechanics is an approximation to this non-linear theory, valid at energy scales much smaller than the Planck scale. Using ideas based on noncommutative | >=