In the book the idea of irreversibility as an inherent property of time is developed theoretically and experimentally. The matter is related with causality, and the method of causal analysis is presented. The quantum causal analysis helps understand the principle of week causality which admits extraction of information from the future without the classical paradoxes. It implies a possibility of observation of the future as the existing reality. So, the acceptance of time irreversibility leads to a striking manifestation of reversibility – signaling in reverse time. Quantum insight allows considering correlations of the distant irreversible processes as nonlocal ones originated from a macroscopic entanglement. The experimental approach to study of macroscopic nonlocality is discussed, and design of the experimental setup is described. The results of experiments on macroscopic nonlocal correlations, the signals in reverse time and their application to the forecast of large-scale random processes are expounded.
In the book the idea of irreversibility as an inherent property of time is developed theoretically and experimentally. The matter is related with causality, and the method of causal analysis is presented. The quantum causal analysis helps understand the principle of week causality which admits extraction of information from the future without the classical paradoxes. It implies a possibility of observation of the future as the existing reality. So, the acceptance of time irreversibility leads to a striking manifestation of reversibility – signaling in reverse time. Quantum insight allows considering correlations of the distant irreversible processes as nonlocal ones originated from a macroscopic entanglement. The experimental approach to study of macroscopic nonlocality is discussed, and design of the experimental setup is described. The results of experiments on macroscopic nonlocal correlations, the signals in reverse time and their application to the forecast of large-scale random processes are expounded.
From classical point of view the full description of a system is the sum of its parties descriptions. Quantum mechanics introduced essential correction in the classical view: the measurable properties of a particle ensemble can exceed the properties sum of its particles. It is impossible to describe such entangled states by the known local field equation. Now nonlocal quantum correlations are well known, they underlie quantum information science and have the practical applications already. On the other hand in macro-physics, in particular, in astrophysics and geophysics a lot of facts about distant dissipative processes correlations (including violating classical causality) not reducible to electromagnetic and gravitation interactions have been collected. These correlations could be explained by their nonlocal nature. Although thermo- dynamic limit now is already a subject of entanglement research, the mentioned large-scale processes have remained out of scope of quantum information. The book “Causality and Reversibility in Irreversible Time” by S. M. Korotaev is the first attempt to fill this gap.
The idea that events are equipped with a partial causal order is central to our understanding of physics in the tested regimes: given two pointlike events A and B , either A is in the causal past of B , B is in the causal past of A , or A and B are space-like separated. Operationally, the meaning of these order relations corresponds to constraints on the possible correlations between experiments performed in the vicinities of the respective events: if A is in the causal past of B , an experimenter at A could signal to an experimenter at B but not the other way around, while if A and B are space-like separated, no signaling is possible in either direction. In the context of a concrete physical theory, the correlations compatible with a given causal configuration may obey further constraints. For instance, space-like correlations in quantum mechanics arise from local measurements on joint quantum states, while time-like correlations are established via quantum channels. Similarly to other variables, however, the causal order of a set of events could be random, and little is understood about the constraints that causality implies in this case. A main difficulty concerns the fact that the order of events can now generally depend on the operations performed at the locations of these events, since, for instance, an operation at A could influence the order in which B and C occur in A ’s future. So far, no formal theory of causality compatible with such dynamical causal order has been developed. Apart from being of fundamental interest in the context of inferring causal relations, such a theory is imperative for understanding recent suggestions that the causal order of events in quantum mechanics can be indefinite. Here, we develop such a theory in the general multipartite case. Starting from a background-independent definition of causality, we derive an iteratively formulated canonical decomposition of multipartite causal correlations. For a fixed number of settings and outcomes for each party, these correlations form a polytope whose facets define causal inequalities. The case of quantum correlations in this paradigm is captured by the process matrix formalism. We investigate the link between causality and the closely related notion of causal separability of quantum processes, which we here define rigorously in analogy with the link between Bell locality and separability of quantum states. We show that causality and causal separability are not equivalent in general by giving an example of a physically admissible tripartite quantum process that is causal but not causally separable. We also show that there are causally separable quantum processes that become non-causal if extended by supplying the parties with entangled ancillas. This motivates the concepts of extensibly causal and extensibly causally separable (ECS) processes, for which the respective property remains invariant under extension. We characterize the class of ECS quantum processes in the tripartite case via simple conditions on the form of the process matrix. We show that the processes realizable by classically controlled quantum circuits are ECS and conjecture that the reverse also holds.
Beyond Causality: Temporal Geometry, Informational Consistency, and the Foundations of Physical Time What if the deepest mystery of time is not whether the past can be reached, but whether causality itself is more fundamental than the physical laws through which we describe it? For more than a century, modern physics has transformed our understanding of space, time, matter, and information. General relativity revealed that temporal order is inseparable from spacetime geometry. Quantum theory challenged classical intuitions about measurement, correlations, and physical reality. Information theory provided a mathematical language for describing what can be known, transmitted, and recovered. Yet a profound question remains: must every physically consistent universe possess a globally ordered sequence of causes and effects? Beyond Causality investigates this question through an extended mathematical and conceptual study of temporal geometry, informational dependence, retrocausal feedback, and global consistency. Organized into six interconnected parts, this 430-page research monograph develops a framework for examining causal structures beyond conventional temporal ordering. It brings together established results from general relativity, quantum information, causal modeling, and fixed-point theory, while exploring additional mathematical constructions designed to clarify the conditions under which temporally nonstandard information networks can remain internally consistent. Particular attention is devoted to distinguishing mathematical self-consistency from physical realizability, statistical correlation from controllable communication, and unconventional temporal descriptions from genuine violations of operational causality. Among its principal investigations are the geometric and energetic constraints associated with localized chronology-violating spacetime models, the existence and stability of globally consistent informational feedback networks, the behavior of finite stochastic systems under intervention, and the relationship between quantum causal structures and hypothetical retrocausal channels. The work also extends the theoretical research program introduced in Eon Reverser: Toward Temporal Bubble Radio Communication, examining what additional mathematical, physical, and experimental conditions would be required before communication with an earlier receiver record could be considered a meaningful scientific possibility. Analytical derivations, formal propositions, computational examples, and reproducibility materials accompany the discussion. The proposed constructions are explicitly distinguished from established physical results, and no experimental evidence for backward-in-time communication is claimed. The central ambition of this monograph is neither to declare that causality can be violated nor to assume that temporal paradoxes admit a universal resolution. It is to ask a more precise question: what mathematical structures, consistency principles, and observable constraints would a physical theory have to satisfy if causal order were not universally fixed? The possibility that time, information, and causality may possess a deeper relationship than our present formulations reveal remains an open intellectual frontier. Exploring that frontier requires imagination disciplined by mathematics, speculation constrained by physical principles, and theoretical proposals that remain accountable to observation. Beyond Causality is offered as a contribution to that exploration: an attempt to extend the questions we can rigorously formulate, identify the limits of existing models, and provide a foundation for further investigation into the nature of physical time. Keywords: Causality; Temporal Geometry; General Relativity; Retrocausality; Closed Timelike Curves; Quantum Causal Structures; Information Theory; Global Consistency; Fixed-Point Theory; Chronology Protection; Advanced Electromagnetic Response; Eon Reverser.
Quantum theory shows that natural laws cannot be understood as ruling single events since the latter occur randomly. Nevertheless, the physical world shows everywhere order whose source cannot be represented by the latter. It is shown that this order is due to the presence of quantum correlations. Since their e↵ect is to reduce the space of the possible events, they can be considered as causal factors. However, being correlations, they do not display the dynamic character that would be required in order to produce a determinate e↵ect. This is why they need additional local factors in order to concur to the production of a certain event. If not so, this would even imply a violation of Einstein’s locality since correlations could be used by themselves to transmit superluminal signals. Due to such a character of correlation, they can be understood as kind of potential reality needing actual (and local) context to be e↵ective. This allows also a distinction that is classically unknown between locality and globality. Such a distinction solves the important problem of measurement showing that ultimately we have irreversible local processes while globally everything is still reversible. In particular, it is a shift of information that can explain this local phenomenon. In fact, quantum systems are essentially information and also the measurement process is ultimately a dealing with information: information processing (preparing a system), information sharing (coupling a system with an apparatus) and information selection (detecting). State, observable and property appear as equivalence classes of these three procedures, respectively. Finally, the distinction between interpreted and uninterpreted ontology is considered in a Kantian perspective, but it is also shown that the approach supported here is rather a critical realism.
Although the general theory macroscopic quantum entanglement is still in its infancy, consideration of the matter in the framework of action-at-a-distance electrodynamics predicted, for the random dissipative processes, observability of the advanced nonlocal correlations (time reversal causality). These correlations were really revealed in our previous experiments with some large-scale random heliogeophysical processes as the source ones and the lab detectors as the probe ones. However, the strongest macroscopic nonlocal correlations are observed at extremely low frequencies; therefore, the long-terms experiments therewith under very stable conditions, which are difficult to achieve in a usual laboratory, are necessary. To overcome this difficulty, a new experiment has been conducted on the base of Baikal Deep Sea Neutrino Observatory since 2012. Baikal thick water layer is an excellent shield against any local impacts on the detectors. The long-term series of measurements demonstrates that detector signals respond to the random global heliogeophysical processes, but this nonlocal causal connection proves to contain considerable time reversal component. Nonlocal nature of this connection is confirmed by violation of the steering inequality. In addition, advanced nonlocal correlation of the detector signal with a regional source-process – the random component of hydrological activity (macroturbulence) in the upper layer is revealed. The possibilities of the random processes forecast on nonlocal correlations are demonstrated.