Quantum mechanics is usually presented starting from a series of postulates about the mathematical framework. In this work we show that those same postulates can be derived by assuming that measurements are discrete interactions: that is, that we measure at specific moments in time (as opposed to a continuous measurement that spans a long time interval) and that the system is in general affected by our measurement. We believe that this way of presenting quantum mechanics would make it easier to understand by laying out a more cohesive view of the theory and making it resonate more with our physics intuition.
Quantum mechanics is usually presented starting from a series of postulates about the mathematical framework. In this work we show that those same postulates can be derived by assuming that measurements are discrete interactions: that is, that we measure at specific moments in time (as opposed to a continuous measurement that spans a long time interval) and that the system is in general affected by our measurement. We believe that this way of presenting quantum mechanics would make it easier to understand by laying out a more cohesive view of the theory and making it resonate more with our physics intuition.
The model of the physical system with discrete interactions is based on the postulates that (i) parameters of the physical system are defined in process of its interaction; (ii) the process of interaction is discrete. Consequently ordering of the events in the system is not automatically implied based on the values of time, but must be specified explicitly. This suggests the specific logic of events as well as complex character of the function, which describes stochastic behavior of the system, hence the parameters of the system are defined by Hermitian operators in the Hilbert space of functions. The model gives an essential way to introduce the basic notions and obtain the results of the quantum theory, to derive the meaning of the main physical parameters, such as momentum or electric charge. Based on the proposed postulates, Schrodinger equation for the particle is deduced in a way similar to inferring of Smoluchowski equation in the classical statistical mechanics. Similarly, the equations of motion of linear fields are established by considering Smoluchowski-type equations for amplitudes of harmonics. The concept of discrete interaction gives a way to de-couple the object of experiment and a testing device (the traditional source of controversy in quantum theory), though at expense of limitation of the principle of locality.
The mathematical formalism of quantum theory in terms of vectors and operators in infinite-dimensional complex vector spaces is very abstract. The definitions of many mathematical quantities used do not seem to have an intuitive meaning, which makes it difficult to appreciate the mathematical formalism and understand quantum mechanics. This book provides intuition and motivation to the mathematics of quantum theory, introducing the mathematics in its simplest and familiar form, for instance, with three-dimensional vectors and operators, which can be readily understood. Feeling confident about and comfortable with the mathematics used helps readers appreciate and understand the concepts and formalism of quantum mechanics. This book is divided into four parts. Part I is a brief review of the general properties of classical and quantum systems. A general discussion of probability theory is also included which aims to help in understanding the probability theories relevant to quantum mechanics. Part II is a detailed study of the mathematics for quantum mechanics. Part III presents quantum mechanics in a series of postulates. Six groups of postulates are presented to describe orthodox quantum systems. Each statement of a postulate is supplemented with a detailed discussion. To make them easier to understand, the postulates for discrete observables are presented before those for continuous observables. Part IV presents several illustrative applications, which include harmonic and isotropic oscillators, charged particle in external magnetic fields and the Aharonov–Bohm effect. For easy reference, definitions, theorems, examples, comments, properties and results are labelled with section numbers. Various symbols and notations are adopted to distinguish different quantities explicitly and to avoid misrepresentation. Self-contained both mathematically and physically, the book is accessible to a wide readership, including astrophysicists, mathematicians and philosophers of science who are interested in the foundations of quantum mechanics.
Quantum mechanics describes certain systems as being in superpositions of their properties, yet every measurement on every system that we are able to perform yields a determinate result. The “orthodox” formulation of the theory builds this in by including a postulate that such superpositions “collapse” at the time of measurement. This strategy fails to really explain why such measurements are determinate, is unacceptably imprecise, and makes observation basic in fundamental physical theory, which looks like the wrong sort of process for the job. The problem of the interpretation of quantum mechanics is the problem of finding a more satisfactory understanding of the formalism in This project began in an independent study with Craig Callender, who provided much help in terms of direction, discussion, comments, and continuing support. Thanks also to Jerey Barrett for reading and commenting on an earlier draft of this paper, including helping me find some clearer and more economical way of putting some crucial points.
In this paper a didactic approach is described which immediately leads to an understanding of those postulates of quantum mechanics used most frequently in quantum computation. Moreover, an interpretation of quantum mechanics is presented which is motivated by retaining the point of view of classical mechanics as much as possible, and which is consistent with relativity theory. Everything can be written down in terms of well-known mathematical formulations that can be found in every textbook about quantum mechanics. Therefore, in this version, almost no formulas are used.
The Nyquist-Shannon Sampling Theorem was refuted in part-1 of this series due to its mathematical flaws, including its circular proof. The theorem implicitly assumes the input signals to be already known deterministically, which makes the signals fundamentally not measurable. In part-2, the problems with the early sampling ideas are explained in verbal detail, while minimizing on the mathematics. This part-3 focuses primarily on the mathematical side of the measurement problem. This problem affects not only sampling, but all Laws of Physics including: Classical Mechanics; Quantum Mechanics; and General Relativity; since these are all based on determinism. Resolving this problem, requires the Laws of Physics to be rephrased in discrete form. The logical information flow in Physics must start with measurements, from which to derive discrete operators to replace the deterministic operators of Classical Physics (including Quantum Mechanics). Symmetric-sampling provides the rules for conducting discrete measurements on a physical system. From a large set of noisy physical measurements, we can derive the best-fit discrete operator and its main eigenvectors which best cover the physical experiment. Such discrete operators, can predict future experimental outcomes. New results can be appended to earlier datasets to further improve the discrete operator, taking advantage of the increased size of the “learning-set”. This “measurement-first” approach unifies Physics under a small set of postulates. The hypothetical “pre-collapse” QM wavefunction Ψ(r,t) in the Schrödinger equation gives way to a five-dimensional “post-collapse” mutual-current-density J(x,y;x',y',t) wavefunction (MCD), a successor to Zernike’s 5D mutual-intensity function: I(x,y;x',y',t). The Schrödinger equation itself will be replaced by a new partial differential equation operating on the MCD.
We argue that a clear view on quantum mechanics is obtained by considering that the unicity of the macroscopic world is a fundamental postulate of physics, rather than an issue that must be mathematically justified or demonstrated. This postulate allows a framework in which quantum mechanics can be constructed, in a complete mathematically consistent way. This is made possible by using general operator algebras to extend the mathematical description of the physical world towards macroscopic systems. Such an approach goes beyond the usual type I operator algebras used in standard textbook quantum mechanics. This avoids a major pitfall, which is the temptation to make the usual type I formalism 'universal'. This may also provide a meta-framework for both classical and quantum physics, shedding a new light on ancient conceptual antagonisms, and clarifying the status of quantum objects. Beyond exploring remote corners of quantum physics, we expect these ideas to be helpful to better understand and develop quantum technologies.