Nature's laws in the domain where relativistic effects, gravitational effects and quantum effects are all comparatively strong are far from understood. This domain is called the Planck scale. Conceivably, a theory can be constructed where the quantum nature of phenomena at such scales can be attributed to something fundamentally simpler. However, arguments that quantum mechanics cannot be explained in terms of any classical theory using only classical logic seem to be based on sound mathematical considerations: there can't be physical laws that require "conspiracy". It may therefore be surprising that there are several explicit quantum systems where these considerations apparently do not apply. In the lecture we will show several such counterexamples. These are quantum models that do have a classical origin. The most curious of these models is superstring theory. This theory is often portrayed as to underly the quantum field theory of the subatomic particles, including the "Standard Model". So now the question is asked: how can this model feature "conspiracy", and how bad is that? Is there conspiracy in the vacuum fluctuations?
Nature's laws in the domain where relativistic effects, gravitational effects and quantum effects are all comparatively strong are far from understood. This domain is called the Planck scale. Conceivably, a theory can be constructed where the quantum nature of phenomena at such scales can be attributed to something fundamentally simpler. However, arguments that quantum mechanics cannot be explained in terms of any classical theory using only classical logic seem to be based on sound mathematical considerations: there can't be physical laws that require "conspiracy". It may therefore be surprising that there are several explicit quantum systems where these considerations apparently do not apply. In the lecture we will show several such counterexamples. These are quantum models that do have a classical origin. The most curious of these models is superstring theory. This theory is often portrayed as to underly the quantum field theory of the subatomic particles, including the "Standard Model". So now the question is asked: how can this model feature "conspiracy", and how bad is that? Is there conspiracy in the vacuum fluctuations?
Arguments that quantum mechanics cannot be explained in terms of any classical theory using only classical logic seem to be based on sound mathematical considerations: there cannot be physical laws that require 'conspiracy'. It may therefore be surprising that there are several explicit quantum systems where these considerations apparently do not apply. In this report, several such counterexamples are shown. These are quantum models that do have a classical origin. The most curious of these models is superstring theory. So now the question is asked: how can such a model feature 'conspiracy', and how bad is that? Is there conspiracy in the vacuum fluctuations? Arguments concerning Bell's theorem are further sharpened.
Abstract Quantum decoherence is the mainstream paradigm in contemporary quantum mechanics foundations and quantum measurement theory for explaining wavefunction collapse, the disappearance of quantum superposition, and the origin of macroscopic classical reality. Its core idea is: a quantum system becomes entangled with its environment, leading to an irreversible attenuation of coherence, thereby transitioning microscopic quantum behavior into macroscopic classical behavior. This paper rigorously proves within the unified framework of Chen’s Superstring Theory (CST) that decoherence is not a fundamental physical process but rather an apparent phenomenon and theoretical patch based on the ontology of point particles and the ultimate theory of linear quantum mechanics. CST takes the three-dimensional Euler spiral energy string as the most fundamental entity of the universe, takes the Planck scale as the dynamic phase transition boundary between the Gravitational string (G) and the Repulsive string (R), and takes logarithmic periodic oscillation as the cross-scale unified dynamical characteristic. From the bottom ontology and dynamical level, CST directly provides a unified quantitative description of quantum coherence, superposition, the measurement process, and classical reality. Through formal derivation and physical image reconstruction, this paper systematically demonstrates that within the CST framework, traditional "decoherence" is completely dissolved, naturally replaced, and entirely redundant. This paper simultaneously presents a micro-macro unified dynamics that requires no decoherence assumption and is self-consistently compatible with existing experimental facts (high-energy scattering, quantum entanglement, celestial orbits, fluid vortices).
The interpretation of quantum theory has always been a controversial subject. Since its inception early this century, it has been apparent that the rules that govern the quantum domain appear to be at odds with the familiar classical universe. Yet quantum theory is without doubt more fundamental. Whenever anything is investigated in detail, quantum rules invariably prevail, yielding correct predictions in all of the tested cases. But everything, including all of the objects we encounter in the "classical domain" of our everyday experience, is undoubtedly made out of quantum pieces. So how can it be that the quantum weirdness never makes it out of the quantum underworld? An ingenious experiment recently carried out at the Kastler-Brossel Laboratory of the Ecole Normale Supérieure in Paris has just begun to explore the quantum-classical boundary (M Brune et al. 1996 Phys. Rev. Lett. 77 4887).
Ever since quantum theory was developed during the first quarter of the 20th century, we have lived with a strange division. Objects in our daily lives behave “normally” – they appear to obey classical physics – whereas microscopic objects can behave counter-intuitively and reveal intriguing features of quantum physics. But where exactly is the boundary between the quantum and classical worlds – if, indeed, there is one? If quantum physics is a universal theory, why is it respectable to talk about the quantum behaviour of electrons but not, say, of footballs?
According to classical physics, particles are basic constituents of the physical world. Quantum theory is much less friendly to particles; in particular, relativistic quantum field theory (RQFT) creates serious obstacles for the idea that particles are fundamental. Apparently, when moving from the domain of RQFT to that of classical mechanics (CM), particles have to emerge at some stage. It is standard to assume that this emergence has been completed at the level of quantum mechanics, halfway between RQFT and CM, even though particles of the same kind in many-particle quantum mechanics have the curious feature of being ‘entities without identity’. Against this ‘Received View’ about the nature of quantum particles we outline and defend an Alternative View (AV), in which the emergent character of particles is emphasized. According to this AV, the step to a particle theory has not yet been made in quantum mechanics: conditions have still to be satisfied in order to make the particle concept applicable. If these conditions are met, the quantum particles that emerge are distinguishable individuals possessing physically defined identities, in stark contrast to what the Received View asserts. We will compare and contrast the two Views, both from a physical and a logical/conceptual point of view. This article is part of the theme issue ‘Identity, individuality and indistinguishability in physics and mathematics’.
Quantum theory has created a fundamental change in our ideas as relativity theory had done before. But while relativity theory is essentially classical in its conceptions—it is in fact the culmination of classical physics—quantum mechanics is founded on some new principles. The quantum laws are very different in character from the laws we find in classical theory. In particular, quantum mechanics is a strictly statistical type of theory : from this arises the different conception of causality that marks the new outlook of modern physics. Classical theory describes the so-called macroscopic phenomena, that is, things and events which are more or less of the same size and kind as we find them in ordinary life; and so a description can be given in terms of concepts close to the ones we use in ordinary language. The language of quantum mechanics is based upon a duality principle ; and most of our ordinary language is equally dualistic.