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Cambridge University Press eBooks

Are there quantum jumps?

J. S. Bell

Published Jun 3, 2004• 7 citations
Publisher

Abstract

If we have to go on with these damned quantum jumps, then I'm sorry that I ever got involved. E. Schrödinger Introduction I have borrowed the title of a characteristic paper by Schrödinger (Schrödinger, 1952). In it he contrasts the smooth evolution of the Schrödinger wavefunction with the erratic behaviour of the picture by which the wavefunction is usually supplemented, or ‘interpreted’, in the minds of most physicists. He objects in particular to the notion of ‘stationary states’, and above all to ‘quantum jumping’ between those states. He regards these concepts as hangovers from the old Bohr quantum theory, of 1913, and entirely unmotivated by anything in the mathematics of the new theory of 1926. He would like to regard the wavefunction itself as the complete picture, and completely determined by the Schrödinger equation, and so evolving smoothly without ‘quantum jumps’. Nor would he have ‘particles’ in the picture. At an early stage, he had tried to replace ‘particles’ by wavepackets (Schrödinger, 1926). But wavepackets diffuse. And the paper of 1952 ends, rather lamely, with the admission that Schrödinger does not see how, for the present, to account for particle tracks in track chambers … nor, more generally, for the definiteness, the particularity, of the world of experience, as compared with the indefiniteness, the waviness, of the wavefunction. It is the problem that he had had (Schrödinger, 1935 a ) with his cat. He thought that she could not be both dead and alive.

DOI
10.1017/cbo9780511815676.024

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If we have to go on with these damned quantum jumps, then I'm sorry that I ever got involved. E. Schrödinger Introduction I have borrowed the title of a characteristic paper by Schrödinger (Schrödinger, 1952). In it he contrasts the smooth evolution of the Schrödinger wavefunction with the erratic behaviour of the picture by which the wavefunction is usually supplemented, or ‘interpreted’, in the minds of most physicists. He objects in particular to the notion of ‘stationary states’, and above all to ‘quantum jumping’ between those states. He regards these concepts as hangovers from the old Bohr quantum theory, of 1913, and entirely unmotivated by anything in the mathematics of the new theory of 1926. He would like to regard the wavefunction itself as the complete picture, and completely determined by the Schrödinger equation, and so evolving smoothly without ‘quantum jumps’. Nor would he have ‘particles’ in the picture. At an early stage, he had tried to replace ‘particles’ by wavepackets (Schrödinger, 1926). But wavepackets diffuse. And the paper of 1952 ends, rather lamely, with the admission that Schrödinger does not see how, for the present, to account for particle tracks in track chambers … nor, more generally, for the definiteness, the particularity, of the world of experience, as compared with the indefiniteness, the waviness, of the wavefunction. It is the problem that he had had (Schrödinger, 1935 a ) with his cat. He thought that she could not be both dead and alive.
If we have to go on with these damned quantum jumps, then I'm sorry that I ever got involved. E. Schrödinger Introduction I have borrowed the title of a characteristic paper by Schrödinger (Schrödinger, 1952). In it he contrasts the smooth evolution of the Schrödinger wavefunction with the erratic behaviour of the picture by which the wavefunction is usually supplemented, or ‘interpreted’, in the minds of most physicists. He objects in particular to the notion of ‘stationary states’, and above all to ‘quantum jumping’ between those states. He regards these concepts as hangovers from the old Bohr quantum theory, of 1913, and entirely unmotivated by anything in the mathematics of the new theory of 1926. He would like to regard the wavefunction itself as the complete picture, and completely determined by the Schrödinger equation, and so evolving smoothly without ‘quantum jumps’. Nor would he have ‘particles’ in the picture. At an early stage, he had tried to replace ‘particles’ by wavepackets (Schrödinger, 1926). But wavepackets diffuse. And the paper of 1952 ends, rather lamely, with the admission that Schrödinger does not see how, for the present, to account for particle tracks in track chambers… nor, more generally, for the definiteness, the particularity, of the world of experience, as compared with the indefiniteness, the waviness, of the wavefunction. It is the problem that he had had (Schrödinger, 1935 a ) with his cat. He thought that she could not be both dead and alive.
In a discussion of Schroedinger’s views on quantum theory John Bell says that Schroedinger did not see how “to account for particle tracks in track chambers…and more generally for the definiteness, the particularity, of experience, as compared with the indefiniteness, the waviness, of the wave function. It is the problem he had had with his cat. He thought it could not be both dead and alive. But the wave function showed no such commitment, superposing the possibilities. Either the wave function as given by the Schroedinger equation is not everything or it is not right” (Bell 1987). At a recent conference Bell sermonized against the employment of “for all practical purpose” reasoning- he called it FAP reasoning-to solve this problem (Bell 1989). He argued that we should not be satisfied with any alleged solution which works “for all practical purposes” only while leaving conceptual puzzles unresolved.
In quantum theory, a particle is allowed to be in a state of coherent superposition among a set of orthogonal states. A vivid picture of this concept is the “Schrödinger cat”: a cat is alive and dead simultaneously. This would be no surprise if one means a large number of an ensemble of cats with 50% alive and 50% dead. But, “Schrödinger cat” is a cat. People are talking about a cat being alive and dead simultaneously. In mathematics, the best word to characterize the relationship between states “alive” and “dead” is perhaps “orthogonal”. In quantum mechanics, the superposition of orthogonal states is used to describe the state of a quantum object, or a particle. The superposition principle is indeed a mystery compared to our everyday classical life experience. Beyond the superposition of orthogonal single-particle states, the superposition of orthogonal multi-particle states represents an even more troubling concept in classical theory.
This research aimed to achieve 2 primary objectives: 1) To study Schrödinger's cat theory and the concept of multiverses, 2) to analyze the interpretations of Schrödinger's cat theory and the concept of multiverses. The data analysis is descriptive.The research results were as follows:1. Schrödinger's cat theory and the Multiverse concept have shown that Schrödinger's Cat theory is a thought experiment in quantum mechanics proposed by Austrian physicist Erwin Schrödinger. It describes the simultaneous multiple states of an atom or entity until it is observed or measured. For instance, in the famous cat-in-a-box experiment, before measurement, the cat exists in a state of both being alive and dead simultaneously, leading to a complex reality in its state. Physicist Hugh Everett later introduced the Many-Worlds Interpretation to address the complexities, giving rise to the concept of parallel universes and the Multiverse.2. When interpreting Schrödinger's cat theory and the multiverse concept, it was discovered that within the framework of Western physics, they involve deductive reasoning and fall into the category of quantity and approximation. However, when interpreted within the framework of Indian metaphysical philosophy, they are associated with inductive reasoning and belong to the category of inference and approximation. This contrast highlights how Schrödinger's Cat theory can be a valuable philosophical tool for discussing ideas related to parallel universes and the Multiverse, especially when considering different approaches to interpretation.These findings shed light on the significance of Schrödinger's Cat theory as a philosophical instrument for exploring the concepts of parallel universes and the Multiverse and for considering the possibilities of diverse states for events occurring simultaneously, even when we only observe a fraction of them.