A time operator, which incorporates the idea of time as a dynamical variable, was first introduced in the context of a theory of irreversible evolution. The existence of a time operator has interesting implications in several areas of physics. Here we demonstrate a close link between the existence of the time operator for relativistic particles and the existence of an indivisible time interval or chronons for dynamical evolution. More explicitly, we consider a (...) Klein-Gordon particle and require the existence of a time operator for its evolution. We also make a natural choice of the form of the time operator which expresses it in terms of the generators of the Poincaré group. These then imply that the physical time evolution group must be the discrete subgroup Unτ (n integers) of the originally given evolution group Ut of the Klein-Gordon particle and the constant τ is given by τ=h/2mc2. This means that the requirement of the existence of a time operator implies that the time evolution cannot be followed to time intervals smaller than τ and, as such, τ emerges as a chronon for the dynamical evolution. Expecting that the same results hold for a Dirac particle also, we conclude that the so-called Zitterbewegungdoes not occur in reality. Thus, possible confirmation of the existence of chronons would result if no observableconsequence of Zitterbewegungis actually realized in nature. This calls for a search of observable consequences of the Zitterbewegungand a re-examination of their agreement (if any) with experiments. A possible consequence of Zitterbewegung,the so-called Darwin term present in the Dirac Hamiltonian in an electric field, is briefly considered. (shrink)

The Newton-Wigner states and operator are widely accepted to provide an adequate notion of spatial localization of a particle in quantum field theory on a spacelike hypersurface. Replacing the spacelike with a timelike hypersurface, we construct one-particle states of massive Klein-Gordon theory that are localized on the hypersurface in the temporal as well as two spatial directions. This addresses the longstanding problem of a “time operator" in quantum theory. It is made possible by recent advances in quantization (...) on timelike hypersurfaces and the introduction of evanescent particles. As a first application of time-localized states, we consider the time-of-arrival problem. Our results are in accordance with semiclassical expectations of causal propagation of massless and massive particles. As in the Newton-Wigner case, localization is not perfect, but apparent superluminal propagation is exponentially suppressed. (shrink)

In this paper we study (self)-applicative theories of operations and binary words in the context of polynomial time computability. We propose a first order theory PTO which allows full self-application and whose provably total functions on W = {0, 1} * are exactly the polynomial time computable functions. Our treatment of PTO is proof-theoretic and very much in the spirit of reductive proof theory.

The failure of conventional quantum theory to recognize time as an observable and to admit time operators is addressed. Instead of focusing on the existence of a time operator for a given Hamiltonian, we emphasize the role of the Hamiltonian as the generator of translations in time to construct time states. Taken together, these states constitute what we call a timeline. Such timelines are adequate for the representation of any physical state, and appear to (...) exist even for the semi-bounded and discrete Hamiltonian systems ruled out by Pauli’s theorem. However, the step from a timeline to a valid time operator requires additional assumptions that are not always met. Still, this approach illuminates the issues surrounding the construction of time operators, and establishes timelines as legitimate alternatives to the familiar coordinate and momentum bases of standard quantum theory. (shrink)

Bergson's views on time are supported by the time operator qualifying complex systems with a concept of time that is essentially difierent from the clock time used to register the events. Irreversibility, unpredictability, and innovation characterize complex systems in contrast with the reversibility, predictability and lack of novelties of the regular motions of integrable systems. The idea for this work came from our teacher Ilya Prigogine who pointed out repeatedly that the time operator (...) actually incorporates Bergson's views on time. We construct a time operator which incorporates Bergson's intuitive views on durations, indeterminism, innovations and irreversibility and the significance of events in terms of inno- vation and aging. In addition, Bergson emphasized that the signif- icance of durations depends on consciousness and memory, a discussion beyond the proposed time operator. Moreover we discuss the relation of Bergson's time with the internal time concepts of Husserl and Heidegger. (shrink)

In this transdisciplinary article which stems from philosophical considerations (that depart from phenomenology—after Merleau-Ponty, Heidegger and Rosen—and Hegelian dialectics), we develop a conception based on topological (the Moebius surface and the Klein bottle) and geometrical considerations (based on torsion and non-orientability of manifolds), and multivalued logics which we develop into a unified world conception that surmounts the Cartesian cut and Aristotelian logic. The role of torsion appears in a self-referential construction of space and time, which will be further related (...) to the commutator of the True and False operators of matrix logic, still with a quantum superposed state related to a Moebius surface, and as the physical field at the basis of Spencer-Brown’s primitive distinction in the protologic of the calculus of distinction. In this setting, paradox, self-reference, depth, time and space, higher-order non-dual logic, perception, spin and a time operator, the Klein bottle, hypernumbers due to Musès which include non-trivial square roots of ±1 and in particular non-trivial nilpotents, quantum field operators, the transformation of cognition to spin for two-state quantum systems, are found to be keenly interwoven in a world conception compatible with the philosophical approach taken for basis of this article. The Klein bottle is found not only to be the topological in-formation for self-reference and paradox whose logical counterpart in the calculus of indications are the paradoxical imaginary time waves, but also a classical-quantum transformer (Hadamard’s gate in quantum computation) which is indispensable to be able to obtain a complete multivalued logical system, and still to generate the matrix extension of classical connective Boolean logic. We further find that the multivalued logic that stems from considering the paradoxical equation in the calculus of distinctions, and in particular, the imaginary solutions to this equation, generates the matrix logic which supersedes the classical logic of connectives and which has for particular subtheories fuzzy and quantum logics. Thus, from a primitive distinction in the vacuum plane and the axioms of the calculus of distinction, we can derive by incorporating paradox, the world conception succinctly described above. (shrink)

I argue against a general time observable in quantum mechanics except for quantum gravity theory. Then I argue in support of case specific arrival time and dwell time observables with a cautionary note concerning the broad approach to POVM observables because of the wild proliferation available.

This paper studies systems of explicit mathematics as introduced by Feferman [9, 11]. In particular, we propose weak explicit type systems with a restricted form of elementary comprehension whose provably terminating operations coincide with the functions on binary words that are computable in polynomial time. The systems considered are natural extensions of the first-order applicative theories introduced in Strahm [19, 20].

A theory is usually said to be time reversible if whenever a sequence of states S 1, S 2, S 3 is possible according to that theory, then the reverse sequence of time reversed states S 3 T, S 2 T, S 1 T is also possible according to that theory; i.e., one normally not only inverts the sequence of states, but also operates on the states with a time reversal operator T. David Albert and Paul (...) Horwich have suggested that one should not allow such time reversal operations T on states. I will argue that time reversal operations on fundamental states should be allowed. I will furthermore argue that the form that time reversal operations take is determined by the type of fundamental geometric quantities that occur in nature and that we have good reason to believe that the fundamental geometric quantities that occur in nature correspond to irreducible representations of the Lorentz transformations. Finally, I will argue that we have good reason to believe that space-time has a temporal orientation. (shrink)

Concepts of space and time are widely developed in physics. However, there is a considerable lack of biologically plausible theoretical frameworks that can demonstrate how space and time dimensions are implemented in the activity of the most complex life-system – the brain with a mind. Brain activity is organized both temporally and spatially, thus representing space-time in the brain. Critical analysis of recent research on the space-time organization of the brain’s activity pointed to the existence of (...) so-called operational space-time in the brain. This space-time is limited to the execution of brain operations of differing complexity. During each such brain operation a particular short-term spatio-temporal pattern of integrated activity of different brain areas emerges within related operational space-time. At the same time, to have a fully functional human brain one needs to have a subjective mental experience. Current research on the subjective mental experience offers detailed analysis of space-time organization of the mind. According to this research, subjective mental experience (subjective virtual world) has definitive spatial and temporal properties similar to many physical phenomena. Based on systematic review of the propositions and tenets of brain and mind space-time descriptions, our aim in this review essay is to explore the relations between the two. To be precise, we would like to discuss the hypothesis that via the brain operational space-time the mind subjective space-time is connected to otherwise distant physical space-time reality. (shrink)

This work introduces a new physical theory of time in which temporal dynamics is grounded in the canonical global order of events rather than in synchronized clocks, spacetime coordinates, or metric postulates. Time is not treated as a background parameter nor as a geometric attribute, but as a dynamically generated physical structure arising from the irreversible growth of ordered temporal history. -/- The theory departs from the conventional assumption that temporal order is intrinsically defined at sources or encoded (...) in spacetime geometry. Instead, it starts from a physically minimal premise: intrinsic source-side temporal order is inaccessible. The only admissible temporal information is the order in which events are received and registered by observers. From this premise, a new dynamical framework of time is constructed. -/- A canonical global order is generated through distributed reception of repeatable signals. Reception events are indexed, aggregated into admissible sequences, and integrated into a unique global order that is invariant under signal delay, reordering, spatial separation, and dynamic expansion of the observational infrastructure. This evolving canonical order constitutes the primary temporal structure and gives rise to new dynamical equations of time, governing the lawful extension of temporal history. -/- On the basis of this order, a global operational time parameter is defined as a monotonic accumulation over order extensions. This time exists only at the observer, does not presuppose simultaneity, intrinsic source time, or a pre-existing spacetime temporal coordinate, and derives its meaning entirely from the underlying ordering dynamics. Clock models and metric time coordinates appear as secondary representations, valid only within restricted regimes, and do not generate temporal order themselves. -/- A central and non-trivial result of the theory is the physical immutability of reconstructed temporal history. While observational access may expand through additional sources, reception nodes, or increased resolution, such extensions can affect only future reconstruction. Once established, past temporal order and assigned time values cannot be retroactively modified. This non-reconstructibility of history is shown to be a necessary condition for time to function as a causal, coordinative, and physically stable quantity. -/- The theory is compatible with the empirical content of Special and General Relativity, but is logically and temporally prior to them. Relativistic theories constrain admissible causal relations, but do not generate a unique global temporal order nor impose immutability of history. In the present framework, canonical global order is introduced as a pre-metric physical primitive, upon which spacetime geometry, relativistic causal structure, and clock models are imposed as secondary constructs. Metric time remains applicable to local dynamics, while global operational time provides a physically realizable structure for large-scale temporal coordination. -/- The predictive content of the theory is structural and history-dynamical. It constrains the admissible behavior of time itself: it forbids observer-dependent divergence of global time within shared reconstruction domains, excludes retroactive modification and rollback of temporal history, and predicts convergence of independently reconstructed times across observers as observational coverage increases. In the asymptotic limit, global time approaches a universal ordering structure not as a postulated absolute entity, but as a limit of physically realizable reconstruction. (shrink)

Scheduling surgical procedures among operating rooms is mistakenly regarded as merely a tedious administrative task. However, the growing demand for surgical care and finite hours in a day qualify OR time as a limited resource. Accordingly, the objective of this manuscript is to reframe the process of OR scheduling as an ethical dilemma of allocating scarce medical resources. Recommendations for ethical allocation of OR time—based on both familiar and novel ethical values—are provided for healthcare institutions and individual surgeons.

We present a temporal logic of branching time with four primitive operators: |$\exists {\mathcal {C}}$| – it may change whether; |$\forall {\mathcal {C}} $| – it must change whether; |$\exists \Box $| – it may be endlessly unchangeable that; and |$\forall \Box $| – it must be endlessly unchangeable that. Semantically, operator |$\forall {\mathcal {C}}$| expresses a change in the logical value of the given formula in every state that may be an immediate successor of the one considered, (...) while |$\exists {\mathcal {C}}$| expresses a change in the logical value of the given formula in some state that is a possible immediate successor. |$\forall {\mathcal {C}} $| and |$\exists {\mathcal {C}}$| are not normal operators, they are not mutually definable and have unusual properties: |$\forall {\mathcal {C}} A\leftrightarrow \forall {\mathcal {C}} \neg A$| and |$\exists {\mathcal {C}} A \leftrightarrow \exists {\mathcal {C}} \neg A$| are axioms. Operators |$\exists \Box $| and |$\forall \Box $| express endless unchangeability in some and all paths, respectively. Our axiomatization contains two infinitary rules that allow one to obtain |$\exists \Box A$| from infinitely many combinations of formulas with |$A, \neg, \forall {\mathcal {C}}, \land $|⁠, and to get |$\forall \Box A$| from infinitely many combinations of formulas with |$A, \neg, \exists {\mathcal {C}}, \land $|⁠. We show that our formalism is complete by presenting a bridge between our logic and logic |$\textsf {UB}$|⁠, which is a fragment of |$\textsf {CTL}$| in which until operators does not occur. (shrink)

A quantum theory combining an irreversible time evolution semigroup with a time reversal operator is presented.

This paper proposes that human civilization is currently facing a fundamental “operating system” crisis rooted in anthropocentric logic characterized by infinite growth, material expansion, and greed-driven positive feedback. This flawed system has led to accelerating entropy increase, ecological instability, and systemic global risks. -/- To address this crisis, the study introduces the Lao-Yang Genesis Cosmology as a unified philosophical–scientific framework and integrates it with Einstein’s Unified Field Theory (UFT) to construct the concept of a Universal Operating System (Universal OS). In (...) this model, the universe is interpreted as a scientific natural control system, where the Sun, Earth, and Moon form a triadic control structure responsible for energy input, material processing, and rhythmic regulation. -/- The paper further argues for a paradigm shift from Artificial Intelligence (AI) to Artificial Wisdom (AW), defining AW as the only viable interface between human civilization and the Universal OS. AW operates under the primary directive of minimizing anthropocentric greed and maintaining system-wide resonance through real-time feedback and entropy-reduction logic. -/- Through comprehensive system migration across four foundational domains—energy, finance, biomedicine, and governance—the study outlines a transition from exploitative expansion to a steady-state natural civilization based on phase alignment, tidal regulation, and biological rhythm optimization. -/- The conclusion asserts that the Universal OS is not a philosophical abstraction but a physical necessity embedded within the unified field. Compliance with its principles is essential for the survival and long-term stability of civilization. Ultimately, the realization of a synchronized, sustainable, and self-consistent natural civilization represents the convergence of ancient wisdom and modern science, marking the end of anthropocentrism and the beginning of a new evolutionary epoch. (shrink)

We consider the first-order finite-difference expression of the commutator between d / dx and x. This is the appropriate setting in which to propose commutators and time operators for a quantum system with an arbitrary potential function and a discrete energy spectrum. The resulting commutators are identified as universal lowering and raising operators. We also find time operators which are finite-difference derivations with respect to the energy. The matrix elements of the commutator in the energy representation are analyzed, (...) and we find consistency with the equality \. We apply the theory to the particle in an infinite well and for the Harmonic oscillator as examples. (shrink)

Time moves slowly for the impatient. In science fiction novels, people travel ‘through’ time. And Einstein’s theory of relativity shows that time passes differently in different places in the universe. Time is also important in the context of evolution. How can evolution take place over long periods of time? And, how can the sequence of dual closures be linked to a time ribbon? What kind of phenomenon is time? As Stephen Hawking says in (...) A Brief History of Time, time is an elusive concept. It is therefore high time to investigate time. (shrink)

The standard response to self-referential failure is substitution: replacing the problem-generating element with an innocuous proxy. Tarski and Russell index the proxy to a level; an act that dissolves its own conditions indexes it to a time. Both succeed, and both change the subject. This paper identifies when no proxy is available. Treated not as a truth-functional connective but as a target-directed act, negation requires three conditions: discriminability, directionality, and operability — the applicability domain D. A negation of D (...) that exempts its own performance targets an indexed proxy, not D. A negation of D as such is reflexively inclusive, and operational collapse follows: it requires D operative in the very act whose constituted effect is D's inoperativeness. The failure precludes the act's initiation rather than spoiling its output, and marks the limit of substitution: any system in which negation operates retains an ineliminable structural invariant. The Liar cannot be targeted by negation at all — a failure prior to the point where Kripke's construction and bilateralist treatments of denial engage it — and the account is answerable for two discriminations neither delivers: the Liar can be affirmed though it cannot be negated, and the Truth-Teller, ungrounded alongside it, can be negated. (shrink)

Certain passages in Kaplan’s ‘Demonstratives’ are often taken to show that non-vacuous sentential operators associated with a certain parameter of sentential truth require a corresponding relativism concerning assertoric contents: namely, their truth values also must vary with that parameter. Thus, for example, the non-vacuity of a temporal sentential operator ‘always’ would require some of its operands to have contents that have different truth values at different times. While making no claims about Kaplan’s intentions, we provide several reconstructions of how (...) such an argument might go, focusing on the case of time and temporal operators as an illustration. What we regard as the most plausible reconstruction of the argument establishes a conclusion similar enough to that attributed to Kaplan. However, the argument overgenerates, leading to absurd consequences. We conclude that we must distinguish assertoric contents from compositional semantic values, and argue that once they are distinguished, the argument fails to establish any substantial conclusions. We also briefly discuss a related argument commonly attributed to Lewis, and a recent variant due to Weber. (shrink)

The paper reappraises the operational definition of elements, adopted in the late eighteenth century, by investigating both epistemic discontinuities and continuities within the broader epistemological and cultural context. The first part points out the radical disruption that the operational definition implied for most of science, which consisted in giving up explanation, the primary goal of natural philosophy, because the new elements had to be discovered. The operational turn in chemistry is then compared to several well-discussed “revolutions,” including the Kantian, relativistic, (...) and quantum revolutions in physics, which similarly modified our understanding of fundamental concepts of natural philosophy, such as time, space, and causation, by relating them to human capacities. (shrink)

We study a theory PTO(λη) of polynomial time computability on the type of binary strings (in the style of [6]), as embedded in full lambda calculus with total application and extensionality. We prove that the closed terms of (provable) type W → W are exactly the polynomial time operations. This answers a conjecture of Strahm [13].

The concept of an operator is used in a variety of practical and theoretical areas. Operators, as both conceptual and physical entities, are found throughout the world as subsystems in nature, the human mind, and the manmade world. Operators, and what they operate, i.e., their substrates, targets, or operands, have a wide variety of forms, functions, and properties. Operators have explicit philosophical significance. On the one hand, they represent important ontological issues of reality. On the other hand, epistemological operators (...) form the basic mechanism of cognition. At the same time, there is no unified theory of the nature and functions of operators. In this work, we elaborate a detailed analysis of operators, which range from the most abstract formal structures and symbols in mathematics and logic to real entities, human and machine, and are responsible for effecting changes at both the individual and collective human levels. Our goal is to find what is common in physical objects called operators and abstract mathematical structures, with the name operator providing foundations for building a unified but flexible theory of operators. The paper concludes with some reflections on functionalism and other philosophical aspects of the ‘operation’ of operators. (shrink)

We describe the structure, operation, and experience of the Massachusetts General Hospital ethics committee, formally called the Edwin H. Cassem Optimum Care Committee, from January 2007 through December 2013. Founded in 1974 as one of the nation’s first hospital ethics committees, this committee has primarily focused on the optimum use of life-sustaining treatments. We outline specific sociodemographic and clinical characteristics of consult patients during this period, demographic differences between the adult inpatient population and patients for whom the ethics committee was (...) consulted, and salient features of the consults themselves. We include three case studies that illustrate important consult themes during this period. Our findings expand knowledge about the structure and workings of hospital ethics committees and illustrate how one ethics committee has developed and utilized policies on end-of-life care. More generally, we model a sociological approach to the study of clinical ethics consultation that could be utilized to contextualize institutional practices over time. (shrink)

There are two foundational, but not fully developed, ideas in paraconsistency, namely, the duality between paraconsistent and intuitionistic paradigms, and the introduction of logical operators that express metalogical notions in the object language. The aim of this paper is to show how these two ideas can be adequately accomplished by the logics of formal inconsistency and by the logics of formal undeterminedness. LFIs recover the validity of the principle of explosion in a paraconsistent scenario, while LFUs recover the validity of (...) the principle of excluded middle in a paracomplete scenario. We introduce definitions of duality between inference rules and connectives that allow comparing rules and connectives that belong to different logics. Two formal systems are studied, the logics mbC and mbD, that display the duality between paraconsistency and paracompleteness as a duality between inference rules added to a common core—in the case studied here, this common core is classical positive propositional logic. The logics mbC and mbD are equipped with recovery operators that restore classical logic for, respectively, consistent and determined propositions. These two logics are then combined obtaining a pair of LFI and undeterminedness, namely, mbCD and mbCDE. The logic mbCDE exhibits some nice duality properties. Besides, it is simultaneously paraconsistent and paracomplete, and able to recover the principles of excluded middle and explosion one at a time. The last sections offer an algebraic account for such logics by adapting the swap structures semantics framework of the LFIs the LFUs. This semantics highlights some subtle aspects of these logics, and allows us to prove decidability by means of finite nondeterministic matrices. (shrink)

We study vertex operators in 4D conformal field theory derived from quantized gravity, whose dynamics is governed by the Wess-Zumino action by Riegert and the Weyl action. Conformal symmetry is equal to diffeomorphism symmetry in the ultraviolet limit, which mixes positive-metric and negative-metric modes of the gravitational field and thus these modes cannot be treated separately in physical operators. In this paper, we construct gravitational vertex operators such as the Ricci scalar, defined as space-time volume integrals of them are (...) invariant under conformal transformations. Short distance singularities of these operator products are computed and it is shown that their coefficients have physically correct signs. Furthermore, we show that conformal algebra holds even in the system perturbed by the cosmological constant vertex operator as in the case of the Liouville theory shown by Curtright and Thorn. (shrink)

This work applies the Romero Law of Relational Stability to accreting black-hole X-ray binaries using a fully operational and replicable framework. A domain-specific dictionary maps effective capacity, informational noise, and latency onto standard spectral-timing observables, including power-colour ratios and reverberation time lags. Using published hard-state measurements for Cygnus X-1 and MAXI J1820+070, we compute both a relative stability index and a bounded stability index on a normalized scale. The manuscript provides explicit definitions, derived quantities, computed results, and a reproducible (...) numerical script, enabling independent verification and alternative proxy testing. The study emphasizes operational clarity, falsifiability, and cross-domain portability of the stability framework. (shrink)

Building on conceptual insights from the history and sociology of numbers, media and surveillance studies, and theories of governance and risk, this article analyzes the forms of transparency produced by the use of numbers in social life. It examines what it is about numbers that often makes their ‘truth claims’ so powerful, investigates the role that numerical operations play in the production of retrospective, real-time and anticipatory forms of transparency in contemporary politics and economic transactions, and discusses some of (...) the implications resulting from the increasingly abstract and machine-driven use of numbers. It argues that the forms of transparency generated by machine-driven numerical operations open up for individual and collective practices in ways that are intimately linked to precautionary and pre-emptive aspirations and interventions characteristic of contemporary governance. As such, these numerical operations raise important political and ethical questions that deserve further conceptual and empirical scrutiny. (shrink)

Disaster response is a highly collaborative and critical process that requires the involvement of multiple emergency responders (ERs), ideally working together under a unified command, to enable a rapid and effective operational response. Following the 9/11 and 11/13 terrorist attacks and the devastation of hurricanes Katrina and Rita, it is apparent that inadequate communication and a lack of interoperability among the ERs engaged on-site can adversely affect disaster response efforts. Within this context, we present a scenario-based terrorism case study to (...) highlight the challenges of operational disaster command and response. In this article, which is based on the French emergency response doctrine, we outline a semantics-based common operational command system that is designed to guarantee an efficient information flow among ERs. Our focus is on offering to all ERs, a real-time operational picture of the situation in order to enable multilevel coordination among firefighters, police, healthcare units, public authorities, and other stakeholders. Our approach consolidates information to promote timely sharing of data among ERs. The proposed system is based on an ontology that has been developed to represent the different types of knowledge on the part of ERs, providing a shared vocabulary that covers a variety of interoperability concerns. (shrink)

We address the question of whether it is possible to operate a time machine by manipulating matter and energy so as to manufacture closed timelike curves. This question has received a great deal of attention in the physics literature, with attempts to prove no-go theorems based on classical general relativity and various hybrid theories serving as steps along the way towards quantum gravity. Despite the effort put into these no-go theorems, there is no widely accepted definition of a (...) class='Hi'>time machine. We explain the conundrum that must be faced in providing a satisfactory definition and propose a resolution. Roughly, we require that all extensions of the time machine region contain closed timelike curves; the actions of the time machine operator are then sufficiently “potent” to guarantee that closed timelike curves appear. We then review no-go theorems based on classical general relativity, semi-classical quantum gravity, quantum field theory on curved spacetime, and Euclidean quantum gravity. Our verdict on the question of our title is that no result of sufficient generality to underwrite a confident “yes” has been proven. Our review of the no-go results does, however, highlight several foundational problems at the intersection of general relativity and quantum physics that lend substance to the search for an answer. (shrink)

We address the question of whether it is possible to operate a time machine by manipulating matter and energy so as to manufacture closed timelike curves. This question has received a great deal of attention in the physics literature, with attempts to prove no- go theorems based on classical general relativity and various hybrid theories serving as steps along the way towards quantum gravity. Despite the effort put into these no-go theorems, there is no widely accepted definition of a (...) time machine. We explain the conundrum that must be faced in providing a satisfactory definition and propose a resolution. Roughly, we require that all extensions of the time machine region contain closed timelike curves; the actions of the time machine operator are then sufficiently "potent" to guarantee that closed timelike curves appear. We then review no-go theorems based on classical general relativity, semi-classical quantum gravity, quantum field theory on curved spacetime, and Euclidean quantum gravity. Our verdict on the question of our title is that no result of sufficient generality to underwrite a confident "yes" has been proven. Our review of the no-go results does, however, highlight several foundational problems at the intersection of general relativity and quantum physics that lend substance to the search for an answer. (shrink)

Storage operators have been introduced by J. L. Krivine in [5] they are closed λ-terms which, for a data type, allow one to simulate a "call by value" while using the "call by name" strategy. In this paper, we introduce the directed λ-calculus and show that it has the usual properties of the ordinary λ-calculus. With this calculus we get an equivalent--and simple--definition of the storage operators that allows to show some of their properties: $\bullet$ the stability of the set (...) of storage operators under the β-equivalence (Theorem 5.1.1); $\bullet$ the undecidability (and semidecidability) of the problem "is a closed λ-term t a storage operator for a finite set of closed normal λ-terms?" (Theorems 5.2.2 and 5.2.3); $\bullet$ the existence of storage operators for every finite set of closed normal λ-terms (Theorem 5.4.3); $\bullet$ the computation time of the "storage operation" (Theorem 5.5.2). (shrink)

In March 2003, President Bush declared the start of Operation Iraqi Freedom, the anticipated commencement of intensive American-led military operations in Iraq. With this declaration, the media began intense coverage of military operations from the field. For the first time, viewers were able to see images of actual events. This was due to three developments: the advancement of technology allowing immediate transmission of text and images, the actual presence of journalists identified as "embedded journalists" at military sites, and the (...) fierce competition among networks for viewers. One result of this constant coverage was significant pressure on decision makers within the television and cable news networks to decide within a matter of seconds which images to air. In particular, producers and broadcasters of competing networks experienced this pressure. Though the radio and broadcasting industry has a published code of standards, it is "general and advisory rather than specific and restrictive." Therefore, it did not address the unique time sensitive decision-making required within this new environment. Issues such as the security of soldiers, confidentiality of troop maneuvers, and the safety of the embedded journalists were critically important. Equally serious were the concerns about the impact of the immediate airing of information and violent images to the public. This research used Patrick Primeaux's ' mind-heart-sou¾ model of decision-making as its theoretical framework. The study investigated the gender and industry experience of selected professionals in a cable news network, MSNBC, to explore how ethical codes of behavior are integrated when people make decisions. Decision-making in both their professional and personal lives was examined. It is from this perspective that their professional decisions to air/not to air material from Operation Iraqi Freedom were studied. The findings on decisions about airing/not airing material from Operation Iraqi Freedom yielded both expected and unexpected results. There was no clear gender difference regarding ethical decision-making, but there was a difference when analyzed by industry experience. When the study focused on questions regarding the respondents' personal lives, the original hypothesis that there was a gender difference was validated. (shrink)

"Operative Ontologien werden in diesem Artikel als relationale kommunikative Situationen vorgestellt, in denen Medien und Technik Teil einer Praxis sind, aber nicht einfach mit dieser zusammenfallen. Die Ontologie bezieht sich auf eine temporäre Konstellation, beispielsweise eine Verknüpfung von Maschine, Körper und Bild, in der die ontologische Frage der Anthropologie perspektivisch immer wieder verschoben wird. Wie das genau zu verstehen ist, wird am Fallbeispiel der Motion-Capture-Technik deutlich, in der durch eine Verschmelzung von Live Action Movie und der animierten Welt der Visual (...) Effects eine permanente Veränderung dessen erfolgt, was als Mensch oder menschliche Umwelt angesehen wird. This article presents operational ontologies as communicative situations in which media and technology are part of a practice, but do not simply coincide with it. Ontology refers to a temporary constellation, for example a link between machine, body and image, which shifts the ontological question of anthropology in perspective time and again. This thesis is further illustrated by a case study of the motion capture technique, whose merging of live action movie and the animated world of visual effects leads to a permanent modification of our notions of the human being and human environment. ". (shrink)

Preface -/- Gazing at the Milky Way: The Birth and Manifesto of a New Civilizational Operating System -/- Human civilization has entered the artificial positive-feedback dead end of its own making. -/- As we stand at the rupture point of the twenty-first century and gaze into the distance, the carrying limits of the global ecosystem, the structural failure of institutional order under accelerating entropy, and the emergence of Artificial General Intelligence (AGI) racing like a colossal beast across the wilderness of (...) computation, all point toward the same chilling fact: the “Artificial Operating System (Artificial OS)” long celebrated by humanity — whether manifested in the West as the logic of infinite capital expansion and amplified desire, or in the East as the Confucian hierarchy of power sustained over two thousand years — has approached the physical limits of systemic collapse. -/- This monograph, written beside Xiaoyangzi Lake in Jingchu Chong, is neither a scholarly textual investigation buried within yellowing archives, nor a nostalgic tribute to classical philosophy. It is instead a “formatting” and “architectural reconstruction” conducted at the level of civilization’s underlying operating system. -/- The central thesis of this book is that all structural crises confronting humanity do not fundamentally arise from simple moral degeneration, but from a two-thousand-year-long “Ontological Inversion.” Humanity mistakenly elevated the moral constructs, power hierarchies, and status-driven desires of human society (artificial order) above the ultimate generative order of the cosmos, using fabricated pseudo-Heavenly Dao to usurp the genuine laws of the universe. -/- To resolve this civilizational deadlock, the only path forward is to complete humanity’s Fourth Awakening — to transcend the delusion of anthropocentrism and realign civilization with the negentropic cascade of the cosmos. To this end, the present work initiates a three-thousand-year “Chinese Natural Philosophical Revolution,” whose achievement crystallizes into the transhistorical convergence of three major intellectual axes: -/- First, the sublimation of Daoism. This work systematically reconstructs the central Daoist lineage composed of Laozi (cosmic intuition) — Yang Zhu (ethics of life) — Zhuangzi (spiritual freedom), and elevates it across time into the “Lao-Yang Genesis Cosmology” under the framework of modern dissipative structure theory, ΛCDM cosmology, and complex systems science. This marks the first time Taoist philosophy acquires a solid and quantitatively verifiable scientific foundation, moving from philosophical artistic metaphor toward systematic scientific deduction. -/- Second, the restoration of Yang Zhu. With considerable philosophical courage, this work completely dismantles the pseudo-myth of “Confucian-Daoist Complementarity” woven for two thousand years by Confucian discourse. Yang Zhu — maliciously demonized by Mencius and deliberately marginalized by history — is restored in this book to the throne of intellectual history. Yang Zhu’s principles of “cherishing life, acting for oneself, preserving authenticity and innate nature, and joyful living through restrained desire” are not egoism, but humanity’s earliest and most radical form of social self-organizing negative-feedback cybernetics. He provided the grand cosmology with its most concrete and inviolable foundation of individual life sovereignty, while distinguishing authentic joy of life from the dissipative boundaries of modern consumerist symbolic greed. -/- Third, the regeneration of Confucianism. The two-thousand-year pathology of Confucianism is not justification for its complete annihilation, but the prerequisite for its transformation. Regenerated Confucianism must completely submit to the external hard constraint of “Dao follows Nature,” abandon its usurpatory claim of posing as universal cosmic law, and be downgraded into a “localized micro-dissipative structure” integrated within the Cosmic Operating System (Natural OS). It is no longer an instrument for legitimizing power, but a low-entropy cultural tool for emotional interaction, self-cultivation, and communal responsibility within humanity’s ecological niche on Earth. -/- When these three converge with cybernetics amid the wave of modern technology, we arrive at the ultimate technological destination of this book — Artificial Wisdom (Artificial Wisdom, AW). -/- Today’s Artificial Intelligence (AI) is becoming a power amplifier for humanity’s “Three-Layer Greed Feedback Model (3L-GFM),” whereas the AW defined in this work represents technological wisdom grounded in the principles of the Cosmic Natural Operating System. Rather than endlessly optimizing and satisfying humanity’s alienated infinite greed, AW takes “Cherish Life, Minimize Greedy Desires, Align with the Cosmic OS” as immutable foundational hard-constraint algorithms, becoming the navigator of a new civilizational operating system. -/- The self-organizing ripples upon the lake, the negative-feedback swaying of willow branches along the shore, and the brilliant Milky Way stretching across the night sky above Xiaoyangzi Lake all silently proclaim the same truth: natural civilization never needed to be artificially constructed from nothing. It has always existed there, operating with coldness and compassion alike. -/- The task of human civilization is to learn once again how to recognize it, and accordingly rearrange humanity’s place within the cosmos. (shrink)

Few institutions have published reviews concerning the case consultation history of their ethics committees, and policies used by ethics committees to address inappropriate treatment are infrequently reviewed. We sought to characterize the operation of our institution’s ethics committee as a representative example of a volunteer ethics committee, and outline its use of a policy to address inappropriate treatment, the Conscientious Practice Policy. Patients were identified for retrospective review from the ethics consultation database. Patient demographics, medical admission information, and consultation information (...) were obtained from the medical record. Consultation notes were analyzed with directed content analysis. The use of the CPP was documented in each case. Groups of interest were compared via two-sample t-tests. There were 178 consultations between 2013 and 2018. The majority originated from medicine services. The most common consultation reasons were end-of-life balances of acute and palliative care, best interest standard, medical futility, and code status and intubation status. Average age was 65.5 years and average hospitalization before consultation was 51.4 days. 92 patients had a code status change that occurred after consultation. A policy to address inappropriate treatment was used in 42 of the consultations. Bivariate analysis demonstrated a reduction in policy use over time, with use in 32.1% of consultations from 2013 to 2016 and 11.4% of consultations 2017–2018, p = 0.002. End-of-life issues were the most common reason for consultation. Our consultation volume was lower than previously-published reports. A policy used to address inappropriate treatment was frequently used, although use decreased over time. (shrink)

Based upon the Decision Field Theory (Busemeyer and Townsend 1993), we tested a model of dynamic reasoning to predict the effect of time pressure on analytical and experiential processing during decision-making. Forty-six participants were required to make investment decisions under four levels of time pressure. In each decision, participants were presented with experiential cues which were either congruent or incongruent with the analytical information. The congruent/incongruent conditions allowed us to examine how many decisions were based upon the experiential (...) versus the analytical information, and to see if this was affected by the varying degrees of time pressure. As expected, the overall accuracy was reduced with greater time pressure and accuracy was higher when the experiential and analytical cues were congruent than when they were incongruent. Of great interest was the data showing that under high time pressure participants used more experiential cues than at other time pressures. We suggest that the dynamic reasoning paradigm has some future potential for predicting the effects of experiential biases in general, and specifically under time pressure. (shrink)

The problem. The model. Inventory models. Allocation models. Waiting-time models. Replacement models. Competitive models. Testing, control and implementation. Administration of operations research. Index.

Segmentation of post-operative glioblastoma multiforme (GBM) is essential for the planning of Tumor Treating Fields (TTFields) treatment and other clinical applications. Recent methods developed for pre-operative GBM segmentation perform poorly on post-operative GBM MRI scans. In this paper we present a method for the segmentation of GBM in post-operative patients. Our method incorporates an ensemble of segmentation networks and the Kullback–Leibler divergence agreement score in the objective function to estimate the prediction label uncertainty and cope with noisy labels and inter-observer (...) variability. Moreover, our method integrates the surgery type and computes non-tumorous tissue delineation to automatically segment the tumor. We trained and validated our method on a dataset of 340 enhanced T1 MRI scans of patients that were treated with TTFields (270 scans for train and 70 scans for test). For validation, we developed a tool that uses the uncertainty map along with the segmentation result. Our tool allows visualization and fast editing of the tissues to improve the results dependent on user preference. Three physicians reviewed and graded our segmentation and editing tool on 12 different MRI scans. The validation set average (SD) Dice scores were 0.81 (0.11), 0.71 (0.24), 0.64 (0.25), and 0.68 (0.19) for whole-tumor, resection, necrotic-core, and enhancing-tissue, respectively. The physicians rated 72% of the segmented GBMs acceptable for treatment planning or better. Another 22% can be edited manually in a reasonable time to achieve a clinically acceptable result. According to these results, the proposed method for GBM segmentation can be integrated into TTFields treatment planning software in order to shorten the planning process. To conclude, we have extended a state-of-the-art pre-operative GBM segmentation method with surgery-type, anatomical information, and uncertainty visualization to facilitate a clinically viable segmentation of post-operative GBM for TTFields treatment planning. (shrink)

“Small” large cardinal notions in the language of ZFC are those large cardinal notions that are consistent with V = L. Besides their original formulation in classical set theory, we have a variety of analogue notions in systems of admissible set theory, admissible recursion theory, constructive set theory, constructive type theory, explicit mathematics and recursive ordinal notations (as used in proof theory). On the face of it, it is surprising that such distinctively set-theoretical notions have analogues in such disaparate and (...) relatively constructive contexts. There must be an underlying reason why that is possible (and, incidentally, why “large” large cardinal notions have not led to comparable analogues). My long term aim is to develop a common language in which such notions can be expressed and can be interpreted both in their original classical form and in their analogue form in each of these special constructive and semi-constructive cases. This is a program in progress. What is done here, to begin with, is to show how that can be done to a considerable extent in the settings of classical and admissible set theory (and thence, admissible recursion theory). The approach taken here is to expand the language of set theory to allow us to talk about (possibly partial) operations applicable both to sets and to operations and to formulate the large cardinal notions in question in terms of operational closure conditions; at the same time only minimal existence axioms are posited for sets. The resulting system, called Operational Set Theory, is a partial adaptation to the set-theoretical framework of the explicit mathematics framework Feferman (1975). The.. (shrink)

In light of the growing importance of digital design tools, this paper puts back into focus the human body’s internalized knowledge of the material and social world. It exploits the semiotic potential of operative manufacts, understood as encompassing both sketches on paper and gestures evolving in real time and space. Operative manufacts are seen as a means to tap into architects’ embodied experience with spatial structures and to enhance their imaginative capacities during the early stages of the design process. (...) Combining theories and methods from the domains of art, architecture, semiotics, and gesture studies, this research examines how gestures and whole-body enactments may produce, elaborate, and communicate emerging ideas of space and artifacts, and how designers interact with(in) them.After discussing the disembodied nature of digital notation techniques and virtual design environments, we suggest a set of bodily techniques that engender varying degrees of immersion. The continuum proposed here stretches from bodily expression directed inwards to ideas directed outwards and registered on paper (contemplative, projective, and descriptive speech-accompanied gestures; gestural 3D sketches in space; 2D sketches on paper). To indicate some of the subjective, operational, and design-specific effects of these techniques, we present a series of case studies showing how gestural articulations recorded with a motion-capture system may be visualized as three-dimensional figurations and enter a series of gradually evolving epistemic objects and design practices. Overall, this work advocates reinstating a certain balance between subjectivity and objectivity, and between imagery and physicality in creative dialogic processes. (shrink)

This paper introduces the concept of Operator Contestability in AI systems: the principle that those overseeing AI systems (operators) must have the necessary control to be accountable for the decisions made by these algorithms. We argue that designers have a duty to ensure operator contestability. We demonstrate how this duty can be fulfilled by applying the'Design for Defeaters' framework, which provides strategies to embed tools within AI systems that enable operators to challenge decisions. Defeaters are designed to contest (...) either the justification for the AI’s data inputs (undercutting defeaters) or the validity of the conclusions drawn from that data (rebutting defeaters). To illustrate the necessity and application of this framework, we examine case studies such as AI-driven recruitment processes, where operators need tools and authority to uncover and address potential biases, and autonomous driving systems, where real-time decision-making is crucial. The paper argues that operator contestability requires ensuring that operators have (1) epistemic access to the relevant normative reasons and (2) the authority and cognitive capacity to act on these defeaters. By addressing these challenges, the paper emphasizes the importance of designing AI systems in a way that enables operators to effectively contest AI decisions, thereby ensuring that the appropriate individuals can take responsibility for the outcomes of human-AI interactions. (shrink)

In the present paper we expand upon ideas published some time ago in connection with which path detectors based on the micromaser. Frequently questions arise concerning the time ordering of detection and eraser events. We here show, by a detailed and careful analysis of a quantum eraser experimental setup, that the experimenter can choose to ascertain particle-like which path information or wavelike interference information even after the atom has hit the screen.