The separate contributions to cosmology of the above researchers are revisited and a cosmology encompassing their basic ideas is proposed.We study Dirac's article on the large number hypothesis (1938), Sciama's proposal of realizing Mach's principle (1953), and Dicke's considerations (1957) on a flat-space representation of general relativity with a variable speed of light (VSL).Dicke's tentative theory can be formulated in a way which is compatible with Sciama's hypothesis on the gravitational constant G. Additionally, such a cosmological model is shown to satisfy Dirac's second 'large number' hypothesis on the total number of particles in the universe being proportional to the square of the epoch.In the same context, Dirac's first hypothesis on an epoch-dependent G -contrary to his prediction-does not necessarily produce a visible time dependence of G.While Dicke's proposal reproduces the classical tests of GR in first approximation, the cosmological redshift is described by a shortening of measuring rods rather than an expansion of space.Since the temporal evolution of the horizon R is governed by Ṙ(t) = c(t), the flatness and horizon problems do not arise in the common form.
The separate contributions to cosmology of the above researchers are revisited and a cosmology encompassing their basic ideas is proposed.We study Dirac's article on the large number hypothesis (1938), Sciama's proposal of realizing Mach's principle (1953), and Dicke's considerations (1957) on a flat-space representation of general relativity with a variable speed of light (VSL).Dicke's tentative theory can be formulated in a way which is compatible with Sciama's hypothesis on the gravitational constant G. Additionally, such a cosmological model is shown to satisfy Dirac's second 'large number' hypothesis on the total number of particles in the universe being proportional to the square of the epoch.In the same context, Dirac's first hypothesis on an epoch-dependent G -contrary to his prediction-does not necessarily produce a visible time dependence of G.While Dicke's proposal reproduces the classical tests of GR in first approximation, the cosmological redshift is described by a shortening of measuring rods rather than an expansion of space.Since the temporal evolution of the horizon R is governed by Ṙ(t) = c(t), the flatness and horizon problems do not arise in the common form.
“Despite almost a century’s worth of study, it is still unclear how general relativity (GR) and quantum theory (QT) should be unified into a consistent theory. The conventional approach is to retain the foundational principles of QT, such as the superposition principle, and modify GR. This is referred to as ‘quantizing gravity’, resulting in a theory of ‘quantum gravity’. The opposite approach is ‘gravitizing QT’ where we attempt to keep the principles of GR, such as the equivalence principle, and consider how this leads to modifications of QT. What we are most lacking in understanding which route to take, if either, is experimental guidance. Here we consider using the Dirac–Pauli representation of free Dirac equation to search for the clues. In particular, we study how the double-slit diffraction experiment, when only one Dirac particle (‘say’ electron) at a time is in the apparatus, could test a gravitizing QT proposal in which the wavefunction collapse emerges on the detector screen from the Dirac–Pauli representation, as an objective process, resolving the measurement problem of QT.” [1] We found that the Dirac–Pauli representation is inherently a unified theory embodying a gravitizing QT proposal that Dirac–Pauli representation as wave nature is manifestation of inertial mass and the Foldy-Wouthuysen representation as particle nature is manifestation of gravitational mass such that the fact, that same physics is involved in these two representations, is simply the validity and exhibition of the principle of equivalence, of GR, in QT. [1] Richard Howl et al 2019 New J. Phys. 21 043047 DOI 10.1088/1367-2630/ab104a
Introduction Contemporary cosmology includes inflation as one of its central components. It corresponds to a period of accelerated expansion thought to have occurred very early in cosmic history, which takes the universe from relatively generic post Planckian era conditions to a stage where it is well described (with exponential accuracy in the number of e-folds) by a flat Robertson–Walker space-time (which describes a homogeneous and isotropic cosmology). It was initially proposed to resolve various naturalness problems: flatness, horizons, and the excess of massive relic objects, such as topological defects, that were expected to populate the universe according to grand unified theories (GUT). Nowadays, it is lauded because it predicts that the universe's mean density should be essentially identical to the critical value, a very peculiar situation which corresponds to a spatially flat universe. The existing data support this prediction. However, its biggest success is claimed to be the natural account for the emergence of the seeds of cosmic structure in terms of primordial quantum fluctuations, and the correct estimate of the corresponding microwave spectrum. This represents, thus, a situation which requires the combined application of general relativity (GR) and quantum theory, and that, moreover, is tied with observable imprints left from the early universe, in both the radiation in cosmic microwave background (CMB), and in the large scale cosmological structure we can observe today. It should not be surprising that, when dealing with attempts to apply our theories to the universe as a whole, we should come face to face with some of the most profound conceptual problems facing our current physical ideas. In fact, J. Hartle had noted long ago [28] that serious difficulties must be faced when attempting to apply quantum theory to cosmology, although the situations that were envisioned in those early works corresponded to the even more daunting problem of full quantum cosmology, and not the limited use of quantum theory to consider perturbative aspects, which is what is required in the treatment of the inflationary origin of the seeds of cosmic structure. This led him and his collaborators to consider the Consistent Histories framework, which is claimed to offer a version of quantum theory that does not rely on any fundamental notion of measurements, as the favored approach to use in such contexts. We will have a bit more to say about this shortly.
Conceptual Problems in Quantum Cosmology The application of quantum theory to cosmology raises a number of conceptual questions, such as the role of the quantum-mechanical notion of “observer” or the absence of a time variable in the Wheeler–DeWitt equation. I point out that a relational formulation of quantum mechanics, and more in general the observation that evolution is always relational, provides a coherent solution to this tangle of problems. A number of confusing issues appear when we try to apply quantum mechanics to cosmology. Quantum mechanics, for instance, is generally formulated in terms of an observer making measurements on a system. In a laboratory experiment, it is easy to identify the system and the observer: but what is the observer in quantum cosmology? Is it part of the same universe described by the cosmological theory, or should we think of it as external to the universe? Furthermore, the basic quantum dynamical equation describing a system including gravity is not the Schrödinger equation, but rather the Wheeler–DeWitt equation, which has no time parameter: is this related to the absence of an observer external to the universe? How do we describe the quantum dynamics of the universe without a time variable in the dynamical equation and without an observer external to the universe? I suggest that clarity on these issues can be obtained by simply recognizing the relational nature of quantum mechanics and more in general the relational nature of physical evolution. In the context of quantum theory, this nature is emphasized by the so-called relational interpretation of quantum mechanics (Rovelli, 1996). The relational nature of evolution, on the other hand, has been pointed out by the partial-observable formulation of general covariant dynamics (Rovelli, 2002). A central observation is that there is a common confusion between two different meanings of the expression “cosmology”. This is discussed below, in Section 15.1.1. A considerable amount of the difficulties mentioned above stems, I argue, from this confusion. The discussion clarifies on the role of the quantum mechanical observer in cosmology, which is considered in Section 15.1.2. In Section 15.2, I briefly describe the relational interpretation of quantum mechanics and some related aspects of quantum theory.
Please download the paper and then read the abstract (since crucial formulas are not appearing in this window, and also hyperlinks are not working). This is just a brief overview: Relativity is inside the light cone phenomena, while Quantum Mechanics is outside the light cone phenomena, dictated just by the scale (i.e. whether we use classical/human scale or sub-atomic scale). This recent paper [ ‘ Quantum principle of relativity’; Andrzej Dragan, Artur Ekert, New. J. Phys. 22 (2020) 033098] has shown that every exotic Quantum effect like superposition, entanglement, probabilistic behavior, multiple paths etc. can be explained just by allowing super-luminal possibility. The 'inside the light cone' phenomena, and the 'outside the light cone' phenomena together span the entire region within the space and time axes. Only in unison they complete the entire picture. We failed to realize that the same spacetime is getting split into 'space like' and 'time like’ regions based on scale. And the reason behind this is not the magical ( ? ) speed of light. That would have turned both relativity and quantum mechanics into mere branches of electromagnetism. The true reason is much deeper and at a very fundamental level of our universe. It turns out that the c is the radial expansion velocity of our universe. But why does the transition from Relativity to Quantum Mechanics happens with decreasing size scale? That’s because, this is what is happens to spatial and temporal dimensions at different scales: 3+1 (Classical regime) <=> 2+2 (Compton regime) <=> 1+3 (Planck regime). Just as space and time exchange roles at the event horizon of a Black Hole, similarly, spatial and temporal dimensions switch roles for extremely small scales (although due to a completely different mechanism). Why this happens is difficult to expalin without the true model of our universe. But, once explained, it becomes "Why didn't I think about it before? I was plain silly!" From the center of universe viewpoint, simultaneity is absolute (as demanded by Sagnac effect), and there is indeed absolute universal time (as demanded by quantum mechanics). From our viewpoint (located at an awkward position in the universe), locality is absolute, and velocity c is the upper limit, and remains constant for every observer. This turns (our) space and time into inseparable twins, and makes (our) time a relative concept. This solves the time problem which had so stubbornly resisted the reconciliation of Quantum Mechanics and General Relativity. Quantum Mechanics and Special Relativity are like two sides of the same coin. But understanding the relation between Quantum Mechanics and General Relativity is a bit tricky, because according to General Relativity, gravity is the warping/curvature of the 4 dimensional spacetime itself. At first sight, Quantum Mechanics and General Relativity seem to be utterly incompatible! But actually, Special Relativity’s big brother General Relativity only complicates things a bit, but does not become inconsistent with Quantum Mechanics altogether. The only difference between the warped spacetime of General Relativity, and the flat spacetime of Special Relativity is very similar to the difference between a stretched rubber membrane, with and without a metal ball placed on it. This paper does not sacrifice any of the spectacular success of General Relativity and also does not compromise with any of the stunningly accurate predictions of Quantum Mechanics. And yet, this paper harmoniously brings Quantum Mechanics and General Relativity together. Just bear in mind that Nature simply cannot afford to make our two greatest theories incompatible. After all, both General Relativity and Quantum Mechanics were based on what nature was actually telling us, and nature herself would be accountable for any genuine contradiction (but not for the breakdown of our physics due to our misunderstanding!). And, by the way, this paper solves some of the most pressing problems in both Physics & Cosmology. The 'Principle of Least Action' which comes closest to a 'Theory of Everything' arises as a direct consequence of better SpaceTime theory proposed in this paper. Also, we can see why the symmetries of nature (which gives rise to the crucial conservation principles in Physics according to the Noether's theorems) arises in the first place. Gentle reminder: Please download the paper and then read the abstract.
Please download the paper and then read the abstract (since crucial formulas are not appearing in this window, and also hyperlinks are not working). This is just a brief overview: Relativity is inside the light cone phenomena, while Quantum Mechanics is outside the light cone phenomena, dictated just by the scale (i.e. whether we use classical/human scale or sub-atomic scale). This recent paper [ ‘ Quantum principle of relativity’; Andrzej Dragan, Artur Ekert, New. J. Phys. 22 (2020) 033098] has shown that every exotic Quantum effect like superposition, entanglement, probabilistic behavior, multiple paths etc. can be explained just by allowing super-luminal possibility. The 'inside the light cone' phenomena, and the 'outside the light cone' phenomena together span the entire region within the space and time axes. Only in unison they complete the entire picture. We failed to realize that the same spacetime is getting split into 'space like' and 'time like’ regions based on scale. And the reason behind this is not the magical ( ? ) speed of light. That would have turned both relativity and quantum mechanics into mere branches of electromagnetism. The true reason is much deeper and at a very fundamental level of our universe. It turns out that the c is the radial expansion velocity of our universe. But why does the transition from Relativity to Quantum Mechanics happens with decreasing size scale? That’s because, this is what is happens to spatial and temporal dimensions at different scales: 3+1 (Classical regime) <=> 2+2 (Compton regime) <=> 1+3 (Planck regime). Just as space and time exchange roles at the event horizon of a Black Hole, similarly, spatial and temporal dimensions switch roles for extremely small scales (although due to a completely different mechanism). Why this happens is difficult to expalin without the true model of our universe. But, once explained, it becomes "Why didn't I think about it before? I was plain silly!" From the center of universe viewpoint, simultaneity is absolute (as demanded by Sagnac effect), and there is indeed absolute universal time (as demanded by quantum mechanics). From our viewpoint (located at an awkward position in the universe), locality is absolute, and velocity c is the upper limit, and remains constant for every observer. This turns (our) space and time into inseparable twins, and makes (our) time a relative concept. This solves the time problem which had so stubbornly resisted the reconciliation of Quantum Mechanics and General Relativity. Quantum Mechanics and Special Relativity are like two sides of the same coin. But understanding the relation between Quantum Mechanics and General Relativity is a bit tricky, because according to General Relativity, gravity is the warping/curvature of the 4 dimensional spacetime itself. At first sight, Quantum Mechanics and General Relativity seem to be utterly incompatible! But actually, Special Relativity’s big brother General Relativity only complicates things a bit, but does not become inconsistent with Quantum Mechanics altogether. The only difference between the warped spacetime of General Relativity, and the flat spacetime of Special Relativity is very similar to the difference between a stretched rubber membrane, with and without a metal ball placed on it. This paper does not sacrifice any of the spectacular success of General Relativity and also does not compromise with any of the stunningly accurate predictions of Quantum Mechanics. And yet, this paper harmoniously brings Quantum Mechanics and General Relativity together. Just bear in mind that Nature simply cannot afford to make our two greatest theories incompatible. After all, both General Relativity and Quantum Mechanics were based on what nature was actually telling us, and nature herself would be accountable for any genuine contradiction (but not for the breakdown of our physics due to our misunderstanding!). And, by the way, this paper solves some of the most pressing problems in both Physics & Cosmology. The 'Principle of Least Action' which comes closest to a 'Theory of Everything' arises as a direct consequence of better SpaceTime theory proposed in this paper. Also, we can see why the symmetries of nature (which gives rise to the crucial conservation principles in Physics according to the Noether's theorems) arises in the first place. Gentle reminder: Please download the paper and then read the abstract.
A new, very different physical model of the universe is proposed. Its virtues include unifying relativity and quantum mechanics, and particles with de Broglie waves. It also appears to provide a truly unified physical basis for electromagnetic, gravitational and nuclear forces. The basic system is a four-dimensional Euclidean space, containing an array of nonlinear "flow" waves. These repeat in one dimension, called [phi]. As in Newtonian mechanics, time is treated as an additional, unidirectional parameter describing the evolution of the system. Nevertheless, this wave system is shown be inherently relativistic. Further self-organizing patterns arise within the overall wave structure. Called "wavicles," these have intrinsic quantized fields, "spin," and rest energy, and represent elementary particles. Relativistic expressions are derived for particle behavior in scalar, vector and gravitational potentials. Proper representations of these potentials, based on the wave fields and associated [phi] flows of wavicles, are also obtained. As in the causal quantum mechanics of de Broglie and Bohm, wavicles exist continuously and follow definite, stochastic trajectories. Although experimentally equivalent to Einstein's special relativity, this theory differs fundamentally from his general relativity and the associated Big Bang model. According to Linde, the latter predict a large-scale space-time curvature roughly 60 orders of magnitude greater than observed values. Here a flat large-scale geometry is predicted, in agreement with the observed distribution of galaxies. This theory is also consistent with recent observations pertaining to the age of the universe.