Arrow Of Time Research Articles

Time arrow without past hypothesis: a toy model explanation

Abstract The laws of Physics are time-reversible, making no qualitative distinction between the past and the future—yet we can only go towards the future. This apparent contradiction is known as the ‘arrow of time problem’. Its current resolution states that the future is the direction of increasing entropy. But entropy can only increase towards the future if it was low in the past, and past low entropy is a very strong assumption to make, because low entropy states are rather improbable, non-generic. Recent works from the Physics literature suggest, however, we may do away with this so-called ‘past hypothesis’, in the presence of reversible dynamical laws featuring expansion. We prove that this is the case in principle, by means of a toy model. The discrete setting of this model allows us to deploy the full rigour of theoretical Computer Science proof techniques. It also allows for numerical exploration. We study a time-symmetric variant; an exponential-growth variant; and a damping variant—exhibiting similar features. The latter slows down thermal death.

Nanothermodynamics: There's Plenty of Room on the Inside.

Nanothermodynamics provides the theoretical foundation for understanding stable distributions of statistically independent subsystems inside larger systems. In this review, it is emphasized that extending ideas from nanothermodynamics to simplistic models improves agreement with the measured properties of many materials. Examples include non-classical critical scaling near ferromagnetic transitions, thermal and dynamic behavior near liquid-glass transitions, and the 1/f-like noise in metal films and qubits. A key feature in several models is to allow separate time steps for distinct conservation laws: one type of step conserves energy and the other conserves momentum (e.g., dipole alignment). This "orthogonal dynamics" explains how the relaxation of a single parameter can exhibit multiple responses such as primary, secondary, and microscopic peaks in the dielectric loss of supercooled liquids, and the crossover in thermal fluctuations from Johnson-Nyquist (white) noise at high frequencies to 1/f-like noise at low frequencies. Nanothermodynamics also provides new insight into three basic questions. First, it gives a novel solution to Gibbs' paradox for the entropy of the semi-classical ideal gas. Second, it yields the stable equilibrium of Ising's original model for finite-sized chains of interacting binary degrees of freedom ("spins"). Third, it confronts Loschmidt's paradox for the arrow of time, showing that an intrinsically irreversible step is required for maximum entropy and the second law of thermodynamics, not only in the thermodynamic limit but also in systems as small as N=2 particles.

Emergent spacetime and the ergodic hierarchy

Various diagnostics of the emergence of an arrow of time in the bulk description of a holographic theory have been proposed, including the decay of some real time correlation functions and the appearance of type III1 von Neumann algebras carrying half-sided modular inclusions. This Letter puts forward a close parallel between these diagnostics and a quantum formulation of the ergodic hierarchy of dynamical systems. Theories with an emergent spacetime appear to sit near the top of this hierarchy. Published by the American Physical Society 2024

The Political Potential of Autonomous Time Generation in Jean Genet's The Balcony

With the development of timekeeping machinery in the late Middle Ages, time became publicly visible on mechanical dials. This way of spatializing time aimed to crystallize the flow of time and experience into eternity at a single moment, reaching its peak in the 19th century. The natural rhythm of time and the discrete temporality of personal experience were strictly unified into a series of points, distributed along a historical timeline that never turns back. This unidirectional arrow of time remains evident in the study of The Balcony. Research on The Balcony has primarily focused on its political expressions in space, often overlooking the potential of theatrical temporality. This indicates that studies of the political aspects of The Balcony are overly focused on the dimension of visibility, neglecting the exploration of theatrical invisibility. This article will utilize textual data and analysis, based on Deleuze's theory of Aion time, to develop a discussion on the pure formal time in Genet's theater, incorporating relevant political concepts to explore its autonomously generated political potential further, focusing on the characteristics of theatrical time that continuously provoke questioning and ambiguity.

The temporal asymmetry of cortical dynamics as a signature of brain states

The brain is a complex non-equilibrium system capable of expressing many different dynamics as well as the transitions between them. We hypothesized that the level of non-equilibrium can serve as a signature of a given brain state, which was quantified using the arrow of time (the level of irreversibility). Using this thermodynamic framework, the irreversibility of emergent cortical activity was quantified from local field potential recordings in male Lister-hooded rats at different anesthesia levels and during the sleep-wake cycle. This measure was carried out on five distinct brain states: slow-wave sleep, awake, deep anesthesia–slow waves, light anesthesia–slow waves, and microarousals. Low levels of irreversibility were associated with synchronous activity found both in deep anesthesia and slow-wave sleep states, suggesting that slow waves were the state closest to the thermodynamic equilibrium (maximum symmetry), thus requiring minimum energy. Higher levels of irreversibility were found when brain dynamics became more asynchronous, for example, in wakefulness. These changes were also reflected in the hierarchy of cortical dynamics across different cortical areas. The neural dynamics associated with different brain states were characterized by different degrees of irreversibility and hierarchy, also acting as markers of brain state transitions. This could open new routes to monitoring, controlling, and even changing brain states in health and disease.

Within Thermal Scales: The Kinetic and Energetic Pull of Chemical Entropy.

Biological systems are fundamentally containers of thermally fluctuating atoms that through unknown mechanisms are structurally layered across many thermal scales from atoms to amino acids to primary, secondary, and tertiary structures to functional proteins to functional macromolecular assemblies and up. Understanding how the irreversible kinetics (i.e., the arrow of time) of biological systems emerge from the equilibrium kinetics of constituent structures defined on smaller thermal scales is central to describing biological function. Muscle's irreversible power stroke - with its mechanochemistry defined on both the thermal scale of muscle and the thermal scale of myosin motors - provides a clear solution to this problem. Individual myosin motors function as reversible force-generating switches induced by actin binding and gated by the release of inorganic phosphate, P i . As shown in a companion article, when N individual switches thermally scale up to an ensemble of N switches in muscle, the entropy of a binary system of switches is created. We have shown in muscle that a change in state of this binary system of switches entropically drives actin-myosin binding (the switch) and muscle's irreversible power stroke, and that this simple two-state model accurately accounts for most key aspects of muscle contraction. Extending this observation beyond muscle, here I show that the chemical kinetics of an ensemble of N molecules differs fundamentally from a conventional chemical analysis of N individual molecules, describing irreversible chemical reactions as being pulled into the future by the a priori defined entropy of a binary system rather than being pushed forward by the physical occupancy of chemical states (e.g., mass action).

Philosophical questions about the arrow of time

Abstract Philosophical questioning about the arrow of time is an active research area, but one with a long and industrious history in both physics and philosophy. This paper begins by distinguishing between a puzzle about the origin of the thermodynamic time asymmetry and questions about whether the thermodynamic time asymmetry can itself explain other temporal asymmetries. It goes on to give a brief description of how the puzzle arises in classical mechanics, followed by an interlude on whether and how quantum mechanics might change the situation. Finally, it takes a closer look at the puzzle in terms of statistical mechanics and one proposed solution.

On Tesla-inspired Extended Quantum-Holographic Framework for Reprogramming Macro-Quantum Correlations of Individual and Collective Consciousness

Nikola Tesla's visions and inventions realized in his controlled altered states of consciousness were considered previously as manifestations of his meditative insights within extended framework of quantum-holographic macroquantum correlations of individual & collective consciousness. This Tesla-inspired paper now focuses on some related psychosomatice aspects of quantum entropy & entanglement, and consequences on the usually observablebiological arrow of time & spiritual-informational time reversal. Finally we discuss some spiritual-informational implicationson free will & individual and collective consciousness reprogramming.

Causal Classification of Spatiotemporal Quantum Correlations.

From correlations in measurement outcomes alone, can two otherwise isolated parties establish whether such correlations are atemporal? That is, can they rule out that they have been given the same system at two different times? Classical statistics says no, yet quantum theory disagrees. Here, we introduce the necessary and sufficient conditions by which such quantum correlations can be identified as atemporal. We demonstrate the asymmetry of atemporality under time reversal and reveal it to be a measure of spatial quantum correlation distinct from entanglement. Our results indicate that certain quantum correlations possess an intrinsic arrow of time and enable classification of general quantum correlations across space-time based on their (in)compatibility with various underlying causal structures.

Modeling the Arrows of Time with Causal Multibaker Maps.

Why do we remember the past, and plan the future? We introduce a toy model in which to investigate emergent time asymmetries: the causal multibaker maps. These are reversible discrete-time dynamical systems with configurable causal interactions. Imposing a suitable initial condition or "Past Hypothesis", and then coarse-graining, yields a Pearlean locally causal structure. While it is more common to speculate that the other arrows of time arise from the thermodynamic arrow, our model instead takes the causal arrow as fundamental. From it, we obtain the thermodynamic and epistemic arrows of time. The epistemic arrow concerns records, which we define to be systems that encode the state of another system at another time, regardless of the latter system's dynamics. Such records exist of the past, but not of the future. We close with informal discussions of the evolutionary and agential arrows of time, and their relevance to decision theory.

Fractional conformal map, qubit dynamics and the Leggett–Garg inequality

Abstract A pure state of a qubit can be geometrically represented as a point on the extended complex plane through stereographic projection. By employing successive conformal maps on the extended complex plane, we can generate an effective discrete-time evolution of the pure states of the qubit. This work focuses on a subset of analytic maps known as fractional linear conformal maps. We show that these maps serve as a unifying framework for a diverse range of quantum-inspired conceivable dynamics, including (i) unitary dynamics,(ii) non-unitary but linear dynamics and (iii) \ non-unitary and non-linear dynamics where linearity (non-linearity) refers to the action of the discrete time evolution operator on the Hilbert space. We provide a characterization of these maps in terms of Leggett-Garg Inequality complemented with No-signaling in Time (NSIT) and Arrow of Time (AoT) conditions.

Inflation and dark matter from the low entropy hypothesis and modeling mechanism of modified gravity

Abstract The hypothesis of low entropy in the initial state of the Universe usually explains the observed entropy increase is in only one time direction: the thermodynamic arrow of time. The Hamiltonian formalism is commonly used in the context of general relativity. The set of Lagrange multipliers are introduced in the formalism, and they are corresponding to the Hamiltonian constraints which are written in terms of ‘weak equality’—the equality is satisfied if the constraints hold. Follow the low-entropy hypothesis, we postulate a modeling mechanism—a weak equality (of modeling) that holds only on the subspace of the theory space of physical models defined by some modeling constraints. By applying the modeling mechanism, we obtain a specific model of modified gravity under specific modeling conditions. We derive a novel equation of modeling from the mechanism, that describes how different gravitational models emerge. The solution of the modeling equation naturally turns out to be the model of R 2-gravity (with additional terms) if ordinary matter is negligible. We also found that this mechanism leads to two models: large-field inflation and wave-like dark matter (DM). Interestingly, the wave-like DM model is supported by the most recent observations of Einstein rings.

Demystifying arrow of time

Demystifying arrow of time

Green and Kubo forge the arrow of time

ABSTRACT Transport theory describes the response of a macroscopic current to a thermodynamic force, thus producing entropy and apparently violating time-reversal symmetry. In this note I report a pedagogical derivation of the Green–Kubo formula for transport coefficients, based on elementary equilibrium statistical mechanics and static response theory, that highlights the intrinsically dynamical nature of this formula and showcases the relation between the apparent breach of time-reversal symmetry and the non-commutativity of the low-frequency / low-wavevector limits of the conserved-density susceptibilities, from which the formula can be established.

Self-attention with temporal prior: can we learn more from the arrow of time?

Many diverse phenomena in nature often inherently encode both short- and long-term temporal dependencies, which especially result from the direction of the flow of time. In this respect, we discovered experimental evidence suggesting that interrelations of these events are higher for closer time stamps. However, to be able for attention-based models to learn these regularities in short-term dependencies, it requires large amounts of data, which are often infeasible. This is because, while they are good at learning piece-wise temporal dependencies, attention-based models lack structures that encode biases in time series. As a resolution, we propose a simple and efficient method that enables attention layers to better encode the short-term temporal bias of these data sets by applying learnable, adaptive kernels directly to the attention matrices. We chose various prediction tasks for the experiments using Electronic Health Records (EHR) data sets since they are great examples with underlying long- and short-term temporal dependencies. Our experiments show exceptional classification results compared to best-performing models on most tasks and data sets.

Quantum Physics, Digital Computers, and Life from a Holistic Perspective

Quantum physics is a linear theory, so it is somewhat puzzling that it can underlie very complex systems such as digital computers and life. This paper investigates how this is possible. Physically, such complex systems are necessarily modular hierarchical structures, with a number of key features. Firstly, they cannot be described by a single wave function: only local wave functions can exist, rather than a single wave function for a living cell, a cat, or a brain. Secondly, the quantum to classical transition is characterised by contextual wave-function collapse shaped by macroscopic elements that can be described classically. Thirdly, downward causation occurs in the physical hierarchy in two key ways: by the downward influence of time dependent constraints, and by creation, modification, or deletion of lower level elements. Fourthly, there are also logical modular hierarchical structures supported by the physical ones, such as algorithms and computer programs, They are able to support arbitrary logical operations, which can influence physical outcomes as in computer aided design and 3-d printing. Finally, complex systems are necessarily open systems, with heat baths playing a key role in their dynamics and providing local arrows of time that agree with the cosmological direction of time that is established by the evolution of the universe.

Origin of the arrow of time in quantum mechanics

We point out that time’s arrow is naturally induced by quantum mechanical evolution, whenever the systems have a very large number [Formula: see text] of nondegenerate states and a Hamiltonian bounded from below. When [Formula: see text] is finite, the arrow is imperfect, since evolution can resurrect past states. In the limit [Formula: see text] the arrow is fixed by the “tooth of time”: the decay of excited states induced by spontaneous emission to the ground state, mediated by interactions and a large number of decay products which carry energy and information to infinity. This applies to individual isolated atoms, and does not require a coupling to a separate large heath bath.

The Decoherent Arrow of Time and the Entanglement Past Hypothesis

If an asymmetry in time does not arise from the fundamental dynamical laws of physics, it may be found in special boundary conditions. The argument normally goes that since thermodynamic entropy in the past is lower than in the future according to the Second Law of Thermodynamics, then tracing this back to the time around the Big Bang means the universe must have started off in a state of very low thermodynamic entropy: the Thermodynamic Past Hypothesis. In this paper, we consider another boundary condition that plays a similar role, but for the decoherent arrow of time, i.e. the subsystems of the universe are more mixed in the future than in the past. According to what we call the Entanglement Past Hypothesis, the initial quantum state of the universe had very low entanglement entropy. We clarify the content of the Entanglement Past Hypothesis, compare it with the Thermodynamic Past Hypothesis, and identify some challenges and open questions for future research.

The Contours of an Interdisciplinary Concept of the Synergistic Complexities

There are analyzed the ‘arrow of time’ effects that generate ‘order out of chaos’ (I. Prigozhin) and the accompanying phenomena that have now arisen in the form of ‘synergistic complexities’ (N. Lapin) – they set trends in the becoming of new Russia and form the image of its future. According to the author, their content and character are determined by the genotype of culture, which can either correspond to the civilizational foundations of the country or be borrowed from other cultures, on that factor the country’s sovereign, stable or, on the contrary, traumatic, crisis development depends. Specifically considered are such types of synergistic complexities as glo-local-enclave spaces, synergistic time, hybrids of social, natural and technical/digital realities, hybrids of human physicality, interference risks, synergistic public consciousness and scientific knowledge of a synergistic type. It is substantiated that their complex nature, non-linear development, respectively, demanded for working out the synergistic interdisciplinary knowledge. Paying tribute to foreign scientists in its development, the author notes that it is dominated by formal and pragmatic methodology, while domestic researchers are dominated by comprehensive, more balanced approaches, including the consideration of national and cultural specifics. The author, taking into account their theoretical and methodological achievements, proposes the contours of the concept of the interdisciplinary paradigm of synergistic complexities with a humanistic core. Conclusions are drawn that on its basis it is possible to develop the political strategy for governing the synergistic complexities, which allows solving the urgent tasks of the country’s sovereign and sustainable development, reproducing the national human capital, preserving the uniqueness of our natural world and developing technological innovations without risks to human existential security.

Space-time description of atoms, part I: Electronic structures, dark matter, and g-factors of electron, muon and tau

The description of atoms is based on 3D time and some relativistic effects about spinning bodies have been published previously. The time displacement of the electrons also plays an important role. While the principal quantum number [Formula: see text] refers to the angular momentum [Formula: see text] observed by external observer, the azimuth quantum number [Formula: see text] refers to the angular momentum [Formula: see text] observed from the electron itself. The intrinsic angular momentum observed by the electron is [Formula: see text] according to Stern–Gerlach experiment, but the angular momentum observed by external observer is about [Formula: see text]. The magnetic quantum numbers are deduced from the mentioned effects and the trajectories of electrons are non-probabilistic and geometrically well determined. The spin quantum number indicates the time arrow toward the future or toward the past. So, the electrons with opposite time arrows can be grouped in pairs, where the nucleus is in the middle. Descriptions of the dark matter particles and the electrons are given. Using the value [Formula: see text] suggested from the QED, the [Formula: see text]-factors of the electron and muon are [Formula: see text]; [Formula: see text], which give excellent agreements with the experiments. So, if we equalize the formulas for [Formula: see text]-factor from QED and this approach, it determines the theoretical value of [Formula: see text], without experiment.