Arguably the most important scientific debate of the 20th Century was that which took place between Albert Einstein and Niels Bohr over the nature of reality. Bohr argued that reality was subjective in nature and therefore depended on the presence of an observer or observing process, while Einstein argued that reality had to be objective. The debate was never resolved, ending prematurely with Einstein's death in 1955. Having outlived Einstein, Bohr's ideas have come to dominate modern physics and Einstein has been somewhat sidelined. Perhaps now it is time to revisit the debate to see if Einstein was correct all along.
Arguably the most important scientific debate of the 20th Century was that which took place between Albert Einstein and Niels Bohr over the nature of reality. Bohr argued that reality was subjective in nature and therefore depended on the presence of an observer or observing process, while Einstein argued that reality had to be objective. The debate was never resolved, ending prematurely with Einstein's death in 1955. Having outlived Einstein, Bohr's ideas have come to dominate modern physics and Einstein has been somewhat sidelined. Perhaps now it is time to revisit the debate to see if Einstein was correct all along.
The debate between Bohr and Einstein on the consistency, completeness, and finality of quantum theory ranks as one of the most significant philosophical debates of the twentieth century. It was a philosophical debate not in the sense that it had a considerable impact on the relatively technical field of the philosophy of physics. It was philosophical because at its root there lay two rival conceptions of physical reality and of our capacity to comprehend physical reality. With the possible exception of the Leibniz-Clarke correspondence in which Leibniz and Clarke - with the latter acting as Newton's frontman - pressed their respective conceptions of space and time in the early part of the eighteenth century, the Einstein-Bohr dialogue has no parallel in the history of physics. Unlike the Leibniz-Clarke correspondence, the Bohr-Einstein debate contained no bitterness and was not based on any personal rivalry. The debate was continuous from about 1927 and lasted right up to Einstein's death in 1955. For the contemporary philosopher of physics the most important episodes took place in the years between 1927 and 1935. However, in one respect at least the differences between Bohr and Einstein predated quantum mechanics itself. One is tempted to view the disagreement between Bohr and Einstein as the opposition of Bohr the revolutionary and Einstein the conservative, and in his best and clearest account of it Bohr certainly writes as if that were so.
The Bohr-Einstein debates of the 20th century represent the most famous intellectual conflict in the history of quantum mechanics. For three decades, Albert Einstein and Niels Bohr clashed over the completeness of quantum theory, the nature of reality, and the role of the observer. Neither convinced the other, and the debate ultimately ended in a pragmatic stalemate: the Copenhagen interpretation was adopted, and metaphysical questions were banished from physics. We apply the Category Error Detector (CED) to this historical debate to demonstrate that both physicists were committing a shared category error. They were attempting to force the invariant, deterministic structure of the Abstraction axis into the localized, probabilistic framework of the Contingency axis. They lacked the two-axis geometry required to see that they were both right, but describing different layers of the manifold. We argue that the Solvay Conferences were the exact historical inflection point where Structural Rationalism should have been born. The failure to do so resulted in a century of theoretical aporia, culminating in the current crisis of unfalsifiable models and particle phantoms.
ASPECTS OF THE DEBATE The debate between Niels Bohr and Albert Einstein concerning the interpretation of quantum mechanics extended from the fifth Solvay Conference in 1927 until the end of Einstein's life. The most dramatic exchange occurred in 1935, when Einstein, in collaboration with B. Podolsky and N. Rosen, published a paper in Physical Review entitled “Can quantum-mechanical description of physical reality be considered complete?”, concluding with a negative answer, and Bohr replied in the same journal, with a paper of the same title but giving a positive answer. Their arguments were restated, in some respects with greater clarity, in the Library of Living Philosophers volume on Einstein in 1949. The disagreements between Bohr and Einstein concerned not only the physical question expressed in the common title of their papers, but also philosophical questions about physical reality and human knowledge. Much light was thrown upon the Bohr–Einstein debate by the theorem of J. S. Bell (1964) and the experiments which it inspired. Bell showed that any physical theory which applies to a pair of spatially separated systems (as considered in the thought experiment of Einstein, Podolsky, and Rosen) and satisfies a certain locality condition will, in certain circumstances, disagree statistically with quantum mechanics. Consequently, the supplementation of the quantum mechanical description envisaged by Einstein and his collaborators (usually referred to as a “hidden variables theory”) must either violate the locality condition or clash with quantum mechanical predictions.
The objective of this article is to demonstrate how the historical debate between materialism and idealism, in the field of Philosophy, extends, in new clothes, to the field of Quantum Physics characterized by realism and anti-realism. For this, we opted for a debate, also historical, between the realism of Albert Einstein, for whom reality exists regardless of the existence of the knowing subject, and Niels Bohr, for whom we do not have access to the ultimate reality of the matter, unless conditioning it to the existence of an observer endowed with rationality, position adopted in the Interpretation of Complementarity (1927) – posture that was expanded in 1935 when Bohr assumed a “relationalist” conception, according to which the quantum state is defined by the relationship between the quantum object and the entire measuring device. This is an extremely important debate, as it further consolidates the results of nascent Quantum Mechanics, guaranteeing Bohr the leadership of the orthodoxy based on the interpretation of complementarity. Here, when dealing with Quantum Theory, we will not make any distinction between the terms Quantum Physics, Quantum Theory or Quantum Mechanics. The entire discussion will be held under the name “Quantum Theory”. Theory that tries to analyze and describe the behavior of physical systems of reduced dimensions, close to the sizes of molecules, atoms and subatomic particles. We hope that the reader will appreciate the genius of these two titans in this field of Physics when they magnificently formulate the arguments that support the object of their defenses.
The objective of this article is to demonstrate how the historical debate between materialism and idealism, in the field of Philosophy, extends, in new clothes, to the field of Quantum Physics characterized by realism and anti-realism. For this, we opted for a debate, also historical, between the realism of Albert Einstein, for whom reality exists regardless of the existence of the knowing subject, and Niels Bohr, for whom we do not have access to the ultimate reality of the matter, unless conditioning it to the existence of an observer endowed with rationality, position adopted in the Interpretation of Complementarity (1927) – posture that was expanded in 1935 when Bohr assumed a “relationalist” conception, according to which the quantum state is defined by the relationship between the quantum object and the entire measuring device. This is an extremely important debate, as it further consolidates the results of nascent Quantum Mechanics, guaranteeing Bohr the leadership of the orthodoxy based on the interpretation of complementarity. Here, when dealing with Quantum Theory, we will not make any distinction between the terms Quantum Physics, Quantum Theory or Quantum Mechanics. The entire discussion will be held under the name “Quantum Theory”. Theory that tries to analyze and describe the behavior of physical systems of reduced dimensions, close to the sizes of molecules, atoms and subatomic particles. We hope that the reader will appreciate the genius of these two titans in this field of Physics when they magnificently formulate the arguments that support the object of their defenses.