The standards of measurement employed in physics are arbitrary; it is shown that in consequence, the equations of motion in classical and quantum mechanics ere linear first order differential equations and that macroscopic phenomena obey the transformations of special relativity. The relations of these statements to microscopic evidence for special relativity and to conservation laws are considered. The physical reasons for the choice of a number of independent physical standards are discussed. The use of quantum phenomena to establish standards of measurements is described and related to the occurrence of fundamental quantum constants of physics.
The standards of measurement employed in physics are arbitrary; it is shown that in consequence, the equations of motion in classical and quantum mechanics ere linear first order differential equations and that macroscopic phenomena obey the transformations of special relativity. The relations of these statements to microscopic evidence for special relativity and to conservation laws are considered. The physical reasons for the choice of a number of independent physical standards are discussed. The use of quantum phenomena to establish standards of measurements is described and related to the occurrence of fundamental quantum constants of physics.
This chapter begins by explaining why physics is the fundamental of all natural sciences. Throughout most its history, atoms were hardly the center of attention in physics. Once called natural philosophy, physics originated in the study of the motion of inanimate objects. From those studies emerged a body of knowledge, including various natural laws, that today we call ‘classical’ physics. Newton's laws of motion, the basis of the science of mechanics, come to mind, as does his law of universal gravitation. These laws are obeyed by objects that in some sense are ‘large’ and, in fact, the laws were discovered after careful observation of the behavior of such objects. The discussion then turns to the focus of the book—the quantum world—where the laws of physics turn out to be different from the laws of classical physics used to explain phenomena in the macroscopic world of everyday life. The book discusses a number of mostly recent experiments on quantum mechanical foundations, most of them involving light at the level of a few photons—sometimes only one.
The premise that physical variables must be viewed as random variables, with observed values, assigned as averages over distributions, is shown to yield the formalisms of thermodynamics, Hamiltonian mechanics, and quantum theory. A general mathematical argument first establishes the validity of an embedding of th space of physical variables in a larger manifold of "hidden" variables and a general structure for the distribution of these variables. Then, by consideration of various ways of specifying the preparation of a system for measurement, the formalisms of physics cited above are deduced. It is also shown that the generalized Langevin equation follows from these premises and is applicable to a wide class of phenomena. This formulation yields a new definition for compatible observables as used in quantum theory and demonstrates, in a natural way, that physical laws should be invariant under orthogonal transformations of certain variables, which in one circumstance include the complex orthogonal transformations of the Lorentz form, as in special relativity. In summary, it appears that most of the formal structure of physical theory is a consequence of the statistical nature of physical variables.
In this paper, we discuss the importance of measurement in quantum mechanics and the so-called measurement problem. Any quantum system can be described as a linear combination of eigenstates of an operator representing a physical quantity; this means that the system can be in a superposition of states that corresponds to different eigenvalues, i.e., different physical outcomes, each one incompatible with the others. The measurement process converts a state of superposition (not macroscopically defined) in a well-defined state. We show that, if we describe the measurement by the standard laws of quantum mechanics, the system would preserve its state of superposition even on a macroscopic scale. Since this is not the case, we assume that a measurement does not obey to standard quantum mechanics, but to a new set of laws that form a “quantum measurement theory”.
The laws of physics were not handed down from above. Neither are they rules somehow built into the structure of the universe. They are ingredients of the models that physicists invent to describe observations. Rather than being restrictions on the behavior of matter, the laws of physics are restrictions on the behavior of physicists. If the models of physics are to describe observations based on an objective reality, then those models cannot depend on the point of view of the observer. This suggests a principle of point-of-view invariance that is equivalent to the principle of covariance when applied to space-time. As Noether showed, space-time symmetries lead to the principles of energy, linear momentum, and angular momentum conservation--essentially all of classical mechanics. It also leads to Lorentz invariance and special relativity. When generalized to the abstract space of functions such as the quantum state vector, point-of-view invariance is identified with gauge invariance. Quantum mechanics is then just the mathematics of gauge transformations with no additional assumptions needed to obtain its rules, including the superposition and uncertainty principles. The conservation and quantization of electric charge follow from global gauge invariance. The electromagnetic force is introduced to preserve local gauge invariance. Although not discussed here, the other forces in the standard model of elementary particles are also fields introduced to preserve local gauge invariance. Gravity can also be viewed as such a field. Thus practically all of fundamental physics as we know it follows directly from the single principle of point-of-view invariance.
The framework of classical physics encompasses the well-established and complete Helmholtz wave equation. Capable of accurately describing the propagation, interference and diffraction of steady-state harmonic waves such as acoustic and electromagnetic waves at the macroscopic scale, this equation has been validated by centuries of experiments and is widely recognized as a definitive formula in fundamental physics. Nevertheless, conventional physics has long imposed a rigid scope of application. The academic community has always adopted one-dimensional real scalar coordinates for the Helmholtz equation, limiting its use to macroscopic material wave fields, while never attempting to apply it to the microscopic quantum realm or the underlying ontological structure of the universe. Meanwhile, starting from the microscopic mathematical characteristics, Heisenberg’s matrix mechanics derives the uncertainty principle based on the non-commutation relation of matrices. It directly proves that microscopic mechanical quantities cannot be fully represented by real scalars, and that the microscopic universe is inherently governed by matrix-dimensional structures. This is the fundamental reason why numerous paradoxes persist within quantum mechanics under the framework of real coordinates. Addressing the dual limitations of existing physical theories, this paper presents original research. While fully retaining the differential operators, wave constraints and steady-state solution rules of the classical Helmholtz equation, and introducing no new physical constants or artificial auxiliary hypotheses, this work merely replaces the real spatial coordinates X and Y in the equation with second-order two-dimensional linear matrix coordinates. On this basis, a novel theoretical system of two-dimensional linear waves tailored for the microscopic ontology of the universe is independently established. To clarify: classical physics only adopts the Helmholtz wave with real coordinates to interpret macroscopic wave motions. By contrast, the Helmholtz wave model built upon two-dimensional linear matrix coordinates is an exclusive original theory proposed in this paper. It forms a brand-new independent classical system for depicting the true microscopic essence of the universe. Employing rigorously verified classical mathematical and physical tools, including the classical Helmholtz wave principle, Heisenberg’s matrix mechanics, the uncertainty principle, the linear projection theorem and the wave field superposition principle, this paper systematically elaborates the mathematical structure, dimensional properties and evolutionary laws of two-dimensional linear waves. It further reveals the ultimate physical nature of quantum measurement collapse. All substances in the microscopic world exist inherently as two-dimensional linear Helmholtz waves. Human macroscopic perception and detection devices can only process one-dimensional real-valued information. Essentially, the act of observation is not the random collapse of the wave function as defined in standard quantum mechanics. Instead, the observing system actively extracts one degree of freedom from the two-dimensional matrix wave. The remaining single dimension undergoes dimensionality reduction and projection onto the one-dimensional real physical space, giving rise to the apparent phenomenon of localized particles. This original theory explains two core experimental puzzles that have perplexed quantum physics for a century, without logical contradictions or ad hoc supplements. First, continuous observation of the interference pattern in the double-slit experiment collects global steady-state information of the superimposed two-dimensional waves, and no dimensional extraction occurs, so no collapse takes place. Second, when a single photon reaches the human retina or a single-point detector conducts fixed-position detection, the observing system imposes localized boundary conditions to forcibly extract dimensions from the wave field. This projects the two-dimensional wave onto the one-dimensional physical space, which manifests macroscopically as wave function collapse. This research breaks down the barrier between macroscopic classical waves and microscopic quantum phenomena. The proposed original classical model provides a unified interpretation of microscopic effects including wave-particle duality and quantum measurement collapse, offering a new fundamental perspective for the research on the grand unification of fundamental physics.
The standard theory of measurements in quantum mechanics is reviewed with special emphasis on the conceptual and epistemological implications. It is concluded that the standard theory remains the only one which is compatible with present quantum mechanics. Hence, if one wants to avoid the conclusion that quantum mechanics only gives probability connections between subsequent observations, the quantum-mechanical equations would have to be modified. Particular attention is paid to the case that the measuring apparatus is macroscopic and its state vector not accurately known before the measurement.