This paper suggests that time travelling scenarios commonly depicted in science fiction introduce problems and dangers for the time traveller. If time travel takes time, then time travellers risk collision with past objects, relocation to distant parts of the universe, and time travel-specific injuries. I propose several models of time travel that avoid the dangers and risks of time travel taking time, and that introduce new questions about the relationship between (...) class='Hi'>time travel and spatial location. (shrink)

Temporal dynamists argue that we should believe that there exists temporal passage because there being passage is the best explanation for the presence of our temporal phenomenology. Some non-dynamists have countered that the presence of passage makes no difference to our temporal phenomenology, and consequently that temporal phenomenology cannot be evidence that there is passage. This paper attempts to bolster this non-dynamist response by offering new arguments for the claim that the presence of passage makes no difference to our phenomenology.

The concept of time-travel is a modern idea which combines the imaginary signification of rational domination, the imaginary signification of technological omnipotence, the imaginary concept of eternity and the imaginary desire for immortality. It is a synthesis of central conceptual schemata of techno-science, such as the linearity and homogeneity of time, the radical separation of subjectivity from the world, the radical separation of the individual from his/her social-historical environment. The emergence of this idea, its spread during the 20th (...) century as a major theme of science fiction literature alongside its dissemination as a scientific hypothesis, its popularity with both the public and the scientific community, are indications of the religious role of techno-science. It is my opinion, finally, that, as a chimera, time-travel is non-feasible and impossible. In order to support my claims, I will briefly outline the origins of the time-travel concept and its epistemological and metaphysical/ontological conditions. If these conditions prove to be absurd, the logical impossibility of time-travel will have been demonstrated. (shrink)

After a lecture in Göteborg by the neuroscientist Benjamin Libet in 1993, the Göteborg-Post carried the headline, ‘Now it has been proven: we are all somewhat behind’. The paper was referring to Libet’s celebrated discovery that the neural precursors of some voluntary actions occur before the conscious awareness of the decision to act. In a series of experiments in the 1980s, Libet showed that in an experimental situation in which subjects were asked to perform a simple voluntary action – raising (...) a finger – these acts were preceded by a rise in electrical activity in the area of the brain responsible for the causation of action, called the ‘readiness potential’ (RP). But the striking discovery is that while the RP is activated 550 msec before the action, the subject’s awareness of their decision to act occurs only 150-200 msec before the action. The conclusion is drawn that the causes of our actions in our brains occur fractionally earlier than our conscious awareness of deciding to do them. Hence the frequent description of the result of Libet’s experiments, that we are ‘living in the past’. (shrink)

The branching time analysis grounds the possibilities entailed by temporal indeterminism in a branching temporal structure. I construct a spatial analog of the branching time analysis – the branching space analysis – according to which the possibilities entailed by spatial indeterminism are grounded in branching spatial structure. The construction proceeds in such a way as to show the analogies between the branching space and branching time analyses. I argue that the two views are a package. In particular: (...) the theoretical virtues of the one are theoretical virtues of the other and so if one ought to be accepted, then the other should also be accepted. And: if one ought to be denied, then the other ought to be denied as well. Thus, the branching space analysis functions either as a counterexample to the reductive strategy embodied in the branching time analysis or as a reasonable extension of it – as a lesson learned from it. (shrink)

The Time Field Model (TFM) presents a radical departure from standard paradigms in theoretical physics, offering a unified framework that redefines time as a dynamic, two component wave field (T+,T−) to harmonize quantum mechanics, gravitation, and cos mology. Challenging mainstream approaches—including string theory (10–26D extra di mensions), loop quantum gravity (discrete spacetime), and ΛCDM cosmology (dark mat ter/energy scaffolding)—TFM resolves long-standing theoretical incompatibilities while re taining empirical fidelity to Einstein’s relativity and reducing to Newtonian grav ity in weak-field (...) limits. Spanning 21 papers, TFM demonstrates how micro–Big Bang time waves drive cosmic expansion, unify fundamental forces, eliminate dark matter/energy, and subtly alter quantum chemistry, all within a single mathematical architecture. Core Innovations and Force Unification. • Wave-Based Time: Time is re-envisioned as a physical field with two interacting com ponents (T+,T−), generating micro–Big Bang fluctuations that quantize spacetime and drive inflation. • Quantum–Gravitational Link: Time-wave dynamics replace gravitons/strings, cou pling quantum fluctuations to spacetime curvature without extra dimensions. • DarkEnergy/MatterElimination: Cosmicaccelerationemergesfromstochastic T+/T− interference, while galactic rotation curves follow natural time-wave compression gradients (no exotic dark matter). • Gauge Symmetries via Time Waves: Electroweak and strong interactions arise from time-wave harmonics, with particle masses/charges determined by resonance in the tem poral field. • Gravity Revisited: Gravity emerges from T+ wave compression `a la Einstein, reducing to general relativity macroscopically, and reproducing Newton’s inverse-square law at low energies. Alignment with Legacy Physics. • Einstein’s Relativity: Recovered as a low-energy approximation; curvature becomes time-wave density gradients. • Quantum Field Theory: Standard Model fields become excitations of the time-wave medium, avoiding renormalization divergences through a natural wave cutoff. • Newtonian Gravity: Emerges from the weak-field limit of T+ compression, aligning with classical observations. • Quantum Chemistry: Prediction: Time-wave perturbations alter orbital energies (∆E ≈ 10−15eV), detectable via high-precision spectroscopy (e.g., hydrogen fine struc ture). • Cosmology: Signature: Time-waveinterference imprints a stochastic “hum” in gravitational wave detectors (LIGO/Virgo at 10–1000Hz). • Particle Physics: Test: Proton decay suppression (TFM forbids p → e+ +π0), contra dicting certain GUT predictions but aligning with current experimental bounds. Condensed Architecture of TFM. • Foundations: Micro–Big Bang expansions; discrete spacetime from T+/T− interactions. • Particle Physics: Baryogenesis; mass/charge from temporal resonance. • Gravity and Black Holes: T+-wave compression; black holes as wave solitons (no singularities). • Cosmic Evolution: Inflation from early time-wave bursts; cyclical universe models via T+/T− recollapse. • Quantum–Cosmic Bridge: Entanglement as nonlocal time-wave coherence; arrow of time from T+/T− asymmetry. By replacing dark-sector conjectures with testable time-wave mechanics and uniting quan tum mechanics and relativity, TFM offers a single coherent blueprint for reality. Its predic tions—from modified spectra in quantum chemistry to a detectable “hum” in gravitational detectors—lay a clear path for falsification. While further validation is required, TFM’s self-consistency and explanatory scope position it as a promising candidate for a post–string theory Theory of Everything. (shrink)

Concepts of time as Astronomical Time, Cultural Time, and Absolute Time are defined, and an idea is developed that Absolute Time flows in reverse.

Sequential Time Theory (STT) defines time as a metrological quantity realized by operational procedures (record, count, resolution), distinct from the coordinate time parameter in spacetime geometry. Starting from the primitive definition Δτ(n)=n k ΔQ_unit, STT internalizes time metrology (L2) and treats spacetime geometry (L1) as a representation of protocol constraints, rendering block-universe interpretations optional rather than required for physical derivations. Physics is reframed as STT-Core + Bridge axioms + Θ_sys, where Θ_sys is an explicit, auditable bundle (...) of system-specific auxiliary assumptions. Within this scheme, SR and GR kinematics arise as representation theorems for defect-free and defect-bearing clock networks; GR curvature is interpreted as a measurable holonomy defect density. Quantum interference is treated as U(1) phase holonomy in sequential update, and a Gaussian diffusion kernel is derived from minimal sequentiality assumptions. The framework is used to compare candidate quantum-gravity routes via Θ-auditing. (shrink)

Sequential Time Theory (STT) is developed as a metrological reconstruction of physical time grounded in the operational act of counting distinguishable events. The theory argues that time is not an ontological dimension but a constructed variable derived from event generation. This framework dissolves long-standing paradoxes concerning the Arrow of Time, the reversibility of physical laws, and the Block Universe by distinguishing the logical sequential index from physical state evolution. STT interprets relativistic time dilation as a (...) delay in event completion and quantum measurement as the generator of temporal advancement. The resulting theory offers a parsimonious alternative to entropy-based, cosmological, or multiverse explanations of temporal asymmetry. (shrink)

This monograph presents Sequential Time Theory (STT), an operational reconstruction of physical time based on the counting of discrete, distinguishable events. The framework resolves classical paradoxes surrounding the arrow of time, relativistic time dilation, and quantum measurement by treating time as a constructed variable rather than an ontological dimension. STT argues that irreversibility arises logically from event accumulation, that relativistic effects reflect delays in event generation, and that quantum collapse represents the registration of discrete physical (...) changes. The theory offers a parsimonious alternative to entropy-based, cosmological, and multiverse explanations of temporal asymmetry. (shrink)

What is time? In this paper, I defend the view that time is change. In Section 1, I introduce the view that time is change and contrast it with an alternative view. In Section 2, I draw on recent developments in higher-order metaphysics to defend a particular theory of change, and therefore, of time. Finally, in Section 3, I respond to several objections to the view that time is change.

This is the final draft of the SEP entry "Branching time" by me and the great Alberto Zanardo. See external links for the published version.

Minding Time: A Philosophical and Theoretical Approach to the Psychology of Time offers an innovative philosophical account of the most fundamental kinds of time representation.

The standard cosmological model (Lambda-CDM) postulates the existence of Dark Energy to explain the accelerating expansion of the universe. While statistically robust, the model lacks a fundamental physical origin for this energy and faces the persistent "Hubble Tension." -/- This paper applies Sequential Time Theory (STT) to cosmology, proposing a paradigm shift where the physical unit of time is not invariant but evolves due to the changing cosmic gravitational potential and quantum coherence scales. We construct a unified model (...) integrating General Relativistic time dilation with a Quantum Damping term derived from STT Vol.2. This model was tested against the full Pantheon+ Unbinned Supernovae dataset (N=1590), utilizing the full covariance matrix including systematic errors. -/- The results reveal that the STT model achieves a goodness-of-fit (chi-squared = 1402.71) that is statistically indistinguishable from the standard Lambda-CDM model (chi-squared = 1402.92) using SNe alone. Significantly, the derived quantum transition scale z_dec = 1.50 (+0.42 / -0.33) is consistent with the peak epoch of cosmic star formation. This suggests that "cosmic acceleration" could be reinterpreted as an illusion caused by the phase transition of time from a quantum-coherent regime to a gravity-dominated classical regime, potentially offering an alternative to the standard Dark Energy hypothesis. (shrink)

This thesis develops a theory of temporal binding, the process by which we temporally integrate sensory features into perceptual experiences. Psychophysical and neurophysiological findings have revealed a remarkable amount of detail into how we engage in temporal binding. However, existing theories in psychology or philosophy do not adequately account for the adaptive and flexible nature of temporal binding, nor do they explain how our capacity to engage in temporal binding connects with our experiences of time more broadly. This thesis (...) addresses these gaps. -/- In Chapter 1, I identify three explanatory problems that a theory of temporal binding must address. It must: (i) account for the many variables that influence temporal binding, (ii) address what I call the problems of neural delay and desynchronisation, and (iii) explicate the relation between the mechanisms underlying temporal binding and our apparent perceptual experiences of time. -/- Chapter 2 argues that so-called brain time theories, which take temporal binding to be the result of synchrony in neural processing, fail to address problems (i) and (ii). -/- In response, I advance my own hybrid theory of temporal binding in Chapter 3. I claim that temporal integration relies on how predictive processing and retrodictive processing are modulated by attention. This theory explains (i) and (ii) by presenting temporal binding as a flexible and adaptive hybrid process that is sensitive to goals, expectations, and actions. I present a range of consequences that follow from this. -/- Chapter 4 addresses how the hybrid theory explains (iii) the explanatory gap between our apparent perceptual experiences of time and the dissociable and fragmented mechanisms that underlie time perception. According to the hybrid theory, our phenomenology that time is perceptually unified is imposed on the world through the attentional modulation of predictive and retrodictive processing. This explanation proposes an alternative to theories that propose the empirically implausible view that the perceived unity is inherited from unity in the mechanisms underlying time perception. While my explanation comes at the ‘cost’ of deflating the phenomenology of our perceived unity of time, these deflations are based on empirically justified arguments. -/- Finally, Chapter 5 presents a framework for empirically testing predictions that the hybrid theory makes about temporal binding. This involves examining three questions about the relation between how the content and our apparent phenomenology of temporal binding depend on attention. I present some hypotheses concerning these questions and new animations that can be used to develop empirical tests of these hypotheses. I end by presenting multiple ways in which we may subjectively inflate the phenomenological richness of our experiences of temporal binding. (shrink)

In a quantum universe with a strong arrow of time, it is standard to postulate that the initial wave function started in a particular macrostate---the special low-entropy macrostate selected by the Past Hypothesis. Moreover, there is an additional postulate about statistical mechanical probabilities according to which the initial wave function is a ''typical'' choice in the macrostate. Together, they support a probabilistic version of the Second Law of Thermodynamics: typical initial wave functions will increase in entropy. Hence, there are (...) two sources of randomness in such a universe: the quantum-mechanical probabilities of the Born rule and the statistical mechanical probabilities of the Statistical Postulate. I propose a new way to understand time's arrow in a quantum universe. It is based on what I call the Thermodynamic Theories of Quantum Mechanics. According to this perspective, there is a natural choice for the initial quantum state of the universe, which is given by not a wave function but by a density matrix. The density matrix plays a microscopic role: it appears in the fundamental dynamical equations of those theories. The density matrix also plays a macroscopic / thermodynamic role: it is exactly the projection operator onto the Past Hypothesis subspace. Thus, given an initial subspace, we obtain a unique choice of the initial density matrix. I call this property "the conditional uniqueness" of the initial quantum state. The conditional uniqueness provides a new and general strategy to eliminate statistical mechanical probabilities in the fundamental physical theories, by which we can reduce the two sources of randomness to only the quantum mechanical one. I also explore the idea of an absolutely unique initial quantum state, in a way that might realize Penrose's idea of a strongly deterministic universe. (shrink)

This paper is an enquiry into the logical, metaphysical, and physical possibility of time travel understood in the sense of the existence of closed worldlines that can be traced out by physical objects. We argue that none of the purported paradoxes rule out time travel either on grounds of logic or metaphysics. More relevantly, modern spacetime theories such as general relativity seem to permit models that feature closed worldlines. We discuss, in the context of Gödel's infamous argument for (...) the ideality of time based on his eponymous spacetime, what this apparent physical possibility of time travel means. Furthermore, we review the recent literature on so-called time machines, i.e., of devices that produce closed worldlines where none would have existed otherwise. Finally, we investigate what the implications of the quantum behaviour of matter for the possibility of time travel might be and explicate in what sense time travel might be possible according to leading contenders for full quantum theories of gravity such as string theory and loop quantum gravity. (shrink)

Two of the most difficult problems in the foundations of physics are (1) what gives rise to the arrow of time and (2) what the ontology of quantum mechanics is. I propose a unified 'Humean' solution to the two problems. Humeanism allows us to incorporate the Past Hypothesis and the Statistical Postulate into the best system, which we then use to simplify the quantum state of the universe. This enables us to confer the nomological status to the quantum state (...) in a way that adds no significant complexity to the best system and solves the ''supervenient-kind problem'' facing the original version of the Past Hypothesis. We call the resultant theory the Humean unification. It provides a unified explanation of time asymmetry and quantum entanglement. On this theory, what gives rise to time's arrow is also responsible for quantum phenomena. The new theory has a separable mosaic, a best system that is simple and non-vague, less tension between quantum mechanics and special relativity, and a higher degree of theoretical and dynamical unity. The Humean unification leads to new insights that can be useful to Humeans and non-Humeans alike. (shrink)

The time-lag argument seems to put some pressure on naïve realism to agree that seeing must happen simultaneously with what is seen; meanwhile, a wide-accepted empirical fact suggests that light takes time to transmit from objects at a distance to perceivers—which implies what is seen happened before seeing, and, accordingly, naïve realism must be false. In this paper, I will, first of all, show that the time-lag argument has in fact involves a misunderstanding concept of simultaneity: according (...) to Special Relativity, simultaneity is a matter of convention rather than a matter of fact, so, in principle, we can stipulate a perceptual conception of simultaneity, according to which what is seen is simultaneous with seeing. Secondly, the generalized time-lag argument has a mistaken view on the perceived events and perceiving; it has a doubtful assumption that these events are momentary in the mathematical sense. Such idealization is the main reason why we have the intuition that the time-lag effect of perceiving is in conflict with our ordinary perceptual experiences. Finally, I argue that the naïve realist account of the perceptual relation is a nontemporal constitutive relation; and hence naïve realism is compatible with the claim that we can perceive things as they were, and it should not be weakened by the time-lag argument. (shrink)

This essay develops a metaphysical account of time in which the present (the Now) is treated as an invariant condition of actualization rather than a moving moment within a temporal sequence. Against the common assumption that time flows and the present passes, the argument proposes that the Now is a singular, non-extended point at which all events are continuously actualized. What is experienced as temporal flow is not the movement of the Now itself but the succession of events (...) occurring within it. -/- Time, in this framework, is not a substance but a dependent condition, arising only where change occurs within space and matter. The Now, as the condition of all actualization, cannot sustain itself and therefore points to a non-temporal ground that holds it open. This leads to a philosophical account of divine presence understood not as a being within time, but as the sustaining source of the Now itself. -/- The essay further argues that the singularity of the Now implies the singularity of the self: identity is constituted not by possible alternatives but by actualization within the one shared present. The resulting framework—referred to as a lemniscatic topology of time—offers a unified account of temporality, agency, and metaphysical grounding. (shrink)

Time plays an ambiguous role in classical physics. On the one hand, classical physics allows for a picture of time largely fitting with common-sense views about time, as one-dimensional, and flowing from past to future. On the other, various features of classical physics and formulations of classical mechanics give a less familiar picture of time, as symmetrical between past and future, with apparent teleological qualities. This chapter surveys these varied temporal features of classical physics and draws (...) some conclusions about how to interpret ‘classical time’. (shrink)

While many aspects of cognition have been shown to be shared between humans and non-human animals, there remains controversy regarding whether the capacity to mentally time travel is a uniquely human one. In this paper, we argue that there are four ways of representing when some event happened: four kinds of temporal representation. Distinguishing these four kinds of temporal representation has five benefits. First, it puts us in a position to determine the particular benefits these distinct temporal representations afford (...) an organism. Second, it provides the conceptual resources to foster a discussion about which of these representations is necessary for an organism to count as having the capacity to mentally time travel. Third, it enables us to distinguish stricter from more liberal views of mental time travel that differ regarding which kind(s) of temporal representation is taken to be necessary for mental time travel. Fourth, it allows us to determine the benefits of taking a stricter or more liberal view of mental time travel. Finally, it ensures that disagreement about whether some species can mentally time travel is not merely the product of unrecognised disagreement about which temporal representation is necessary for mental time travel. We argue for a more liberal view, on the grounds that it allows us to view mental time travel as an evolutionarily continuous phenomenon, and to recognise that differences in the ways that organisms mentally time travel might reflect different temporal representations, or combinations thereof, that they employ. Our ultimate aim, however, is to create the conceptual framework for further discussion regarding what sorts of temporal representations are required for mental time travel. (shrink)

Branching time is a popular theory of time that is intended to account for the openness of the future. Generally, branching-time models the openness of the future by positing a multiplicity of concrete alternative futures mirroring all the possible ways the future could unfold. A distinction is drawn in the literature among branching-time theories: those that make use of moment-based structures and those that employ history-based ones. In this paper, I introduce and discuss a particular kind (...) of openness relative to the possibility that time ends (doomsday). I then show that whereas moment-based branching structures cannot represent this kind of openness, history-based structures can account for it. The conclusion is that history-based structures have an advantage over moment-based ones. (shrink)

Recent discussions in Foundations of Science have revived the “two-times problem’’ - the apparent conflict between the formal symmetry of physical time and the experiential asymmetry of becoming. This paper develops an operational resolution based on the concept of closure: the completion of radiative relations between emission and absorption events. Time is defined as the ordered accumulation of such realized closures, forming a Lorentzcoherent record of the world. Each closure adds a new element to this record without invoking (...) a global present or subjective flow. By examining clock networks and atomic emission–absorption cycles, the paper shows how duration arises from measurable waiting intervals, how temporal flow corresponds to the sequential realization of closures, and how asymmetry follows from the irreversible structure of emission and record formation. The future remains open as a set of lawful but unrealized possibilities, while the realized domain expands locally through Past-Only Lorentz Equivariance. The resulting framework reconciles the empirical structure of relativity with the probabilistic openness of quantum mechanics and clarifies how experiential passage emerges from the progressive integration of newly realized records. The two-times problem thereby dissolves: the universe does not evolve in time - it generates time through the accumulation of realized relations. (shrink)

In "Changing the Past" (2010), Peter van Inwagen argues that a time traveler can change the past without paradox in a growing block universe. After erasing the portion of past existence that generates paradox, a new, non-paradox-generating block can be "grown" after the temporal relocation of the time traveler. I articulate and explore the underlying mechanism of Van Inwagen's model: the time traveler's control over the location of the objective present. Van Inwagen's model is aimed at preventing (...) paradox by changing the past, but it achieves something broader than paradox avoidance: it gives tools for a new model of time travel. I use van Inwagen's tools to develop a new kind of time travel in which in which the location of the objective present is shifted by the time traveler. I call this type of time travel Movable Objective Present, or MOP. After defining MOP, I argue that it is compatible with any theory of time that accepts hypertime, including presentism and moving spotlight theory. (shrink)

Future-biased individuals systematically prefer positively valenced events to be in the future (positive future-bias) and negatively valenced events to be in the past (negative future-bias). The most extreme form of future-bias is absolute future-bias, whereby we completely discount the value of past events when forming our preferences. Various authors have thought that we are absolutely future-biased (Sullivan (2018:58); Parfit (1984:173) and that future-bias (absolute or otherwise) is at least rationally permissible (Prior (1959), Hare (2007; 2008), Kauppinen (2018), Heathwood (2008)). The (...) permissibility of future-bias is often held to be grounded in the structure of the temporal dimension. In this paper I consider several proposals for grounding the permissibility of such preferences and evaluate these in the light of the preferences we would have, and judge that we should have, in various time-travel scenarios. I argue that what we learn by considering these scenarios is that these preferences really have nothing to do with temporal structure. So if something grounds their permissibility, it is not temporal structure. (shrink)

On one popular view, the general covariance of gravity implies that change is relational in a strong sense, such that all it is for a physical degree of freedom to change is for it to vary with regard to a second physical degree of freedom. At a quantum level, this view of change as relative variation leads to a fundamentally timeless formalism for quantum gravity. Here, we will show how one may avoid this acute ‘problem of time’. Under our (...) view, duration is still regarded as relative, but temporal succession is taken to be absolute. Following our approach, which is presented in more formal terms in, it is possible to conceive of a genuinely dynamical theory of quantum gravity within which time, in a substantive sense, remains. 1 Introduction1.1 The problem of time1.2 Our solution2 Understanding Symmetry2.1 Mechanics and representation2.2 Freedom by degrees2.3 Voluntary redundancy3 Understanding Time3.1 Change and order3.2 Quantization and succession4 Time and Gravitation4.1 The two faces of classical gravity4.2 Retaining succession in quantum gravity5 Discussion5.1 Related arguments5.2 Concluding remarks. (shrink)

Thinking about time travel is an entertaining way to explore how to understand time and its location in the broad conceptual landscape that includes causation, fate, action, possibility, experience, and reality. It is uncontroversial that time travel towards the future exists, and time travel to the past is generally recognized as permitted by Einstein’s general theory of relativity, though no one knows yet whether nature truly allows it. Coherent time travel stories have added flair to (...) traditional debates over the metaphysical status of the past, the reality of temporal passage, and the existence of free will. Moreover, plausible models of time travel and time machines can be used to investigate the subtle relation between space-time structure and causality. -/- It surveys some philosophical issues concerning time travel and should serves as a quick introduction. It includes a new and improved way to define a time machine. (shrink)

The epistemology of self-locating belief concerns itself with how rational agents ought to respond to certain kinds of indexical information. I argue that those who endorse the thesis of Time-Slice Rationality ought to endorse a particular view about the epistemology of self-locating belief, according to which ‘essentially indexical’ information is never evidentially relevant to non-indexical matters. I close by offering some independent motivations for endorsing Time-Slice Rationality in the context of the epistemology of self-locating belief.

In this paper, I argue that the thesis that time travel is logically possible, is inconsistent with the necessary truth of any of the usual ‘open futureobjective present’ models of the universe. It has been relatively uncontroversial until recently to hold that presentism is inconsistent with the possibility of time travel. I argue that recent arguments to the contrary do not show that presentism is consistent with time travel. Moreover, the necessary truth of other open future-objective present (...) models which we might, prima facie, have supposed to be more amenable to the possibility of time travel, turn out also to be inconsistent with this possibility. (shrink)

This chapter offers a brief overview of the main analogies between time and modality. The first part of the chapter is devoted to the analogy between presentism and actualism. The second part explores the analogy between non-presentist theories and possibilism. The third part discusses the analogy between temporal and modal persistence.

In ‘from times to worlds and back again: a transcendentist theory of persistence’ (henceforth TTP) Alessandro Giordani outlines five competitor views regarding the manner in which objects occupy regions along a dimension. These are: (1) classical uni-location (2) bare uni-location (3) multi-location (4) counterpart presence and (5) transcendent presence. Each view comes in both a temporal and modal version and Giordani argues that one ought to prefer transcendentism (i.e. 5) along both dimensions. According to temporal transcendentism, necessarily, no object is (...) exactly located at any region along the temporal dimension. Instead, any object, O, is derivatively present at some region, R, along the temporal dimension in virtue of bearing certain relations to something (according to TTP an event) that occupies R along that dimension. According to modal transcendentism, no object is exactly located at any region along the modal dimension. Instead, any object, O, is derivatively present at some region, R, along the modal dimension in virtue of bearing certain relations to something (according to TTP an event) that occupies R along that dimension. I argue that such a view is under motivated, and, at any rate, may not in fact offer a distinct view. (shrink)

Kadri Vihvelin, in "What time travelers cannot do" (Philos Stud 81: 315-330, 1996), argued that "no time traveler can kill the baby who in fact is her younger self, because (V1) "if someone would fail to do something, no matter how hard or how many times she tried, then she cannot do it", and (V2) if a time traveler tried to kill her baby self, she would always fail. Theodore Sider (Philos Stud 110: 115-138, 2002) criticized Vihvelin's (...) argument, and Ira Kiourti (Philos Stud 139: 343-352, 2008) criticized both Vihvelin's argument and Sider's critique. I present a critique of Vihvelin's argument different from both Sider's and Kiourti's critiques: I argue in a novel way that both V1 and V2 are false. Since Vihvelin's argument might be understood as providing a challenge to the possibility of time travel, if my critique succeeds then time travel survives such a challenge unscathed. (shrink)

Sequential Time Theory (STT) provides a metrological foundation for physics, defining time through operational procedures rather than as a geometric coordinate. STT CR (Metrological Completion of Relativity) established a formal framework: Physics = (STT-Core -> Bridge -> L1) -> Θ_sys Physical Systems, where L1 is the formal language of dynamics, L2 (STT-Core) is the operational definition of time, and Θ_sys is the mapping rule to specific physical systems. This paper applies this framework to audit the Standard Model (...) (Θ_SM), focusing on the Higgs mechanism. -/- We propose that mass is not a primitive quantity but is defined through the time unit process: m = h * (c^2 * ΔQ_unit)^-1. From Bridge axiom B4 (local calibration consistency), we derive that mass must be determined by a spatially uniform Lorentz-scalar quantity. From metrological constraints on ΔQ_unit -- positivity (C1), finiteness (C2), and statistical reproducibility (C3) -- together with an explicit minimality assumption (Θ_minimal), we derive the form of the Higgs potential V(φ) = -μ^2 |φ|^2 + λ |φ|^4, where the derivation is conditional on the stated assumptions. -/- We show that, for UV-complete fundamental descriptions, renormalizability is a metrological necessity: otherwise the operational distribution of clock-ticks becomes resolution-dependent in a way that cannot be removed by finitely many calibrations (violating C3 and B4). Effective-field descriptions can still satisfy C3 within a finite resolution window. -/- Finally, we present a testable prediction distinguishing STT from standard quantum mechanics: intrinsic clock fluctuations scale as σ_Q ∝ m^-2, predicting the ratio σ_Q(e) : σ_Q(μ) ≈ m_μ : m_e ≈ 207 for electrons versus muons. (shrink)

Time travel is a recognized concept in philosophy and science, but whose scope is highly disputed, giving rise to numerous paradoxes in both philosophy and science. Time travel is considered by some accepted both in general relativity and quantum mechanics, but there is a unanimous consensus that it is not feasible with current technology. (Hawkins 2010) The raised issues are different for the time travel in the past compared to the time travel in the future.

When an individual A is accused of having committed a morally impermissible action X, it is generally accepted that they may invoke three types of defenses to mitigate, or even eliminate, their moral responsibility (or at least the fittingness of blame): justifications, excuses, and exemptions. However, another consideration – one that does not prima facie fall under any of these three types of defenses – also appears capable of influencing moral responsibility: the passage of time. A might argue that, (...) although they did indeed commit the morally impermissible action X, the fact that it occurred twenty years ago partially absolves them from responsibility. This idea, which underlies several legal principles – such as statutes of limitations, rehabilitation, and sentence reduction – raises underexplored philosophical issues. In this paper, we argue that the passage of time does not constitute an autonomous moral defense. Rather, it is morally relevant only insofar as it makes possible certain transformations – including psychological reform, repentance, and processes of moral repair – capable of modifying the normative conditions under which it is appropriate to hold an agent to account. Accordingly, the attenuation of diachronic responsibility is best understood not as a direct consequence of temporal distance itself, but as a consequence of changes in those normative conditions. (shrink)

Contemporary accounts of time and personal identity remain divided between physicalist, phenomenological, and psychological models, none of which provide a unified structural explanation of why temporal flow is experienced as continuous, why identity persists across change, or how experiential continuity arises from discrete processes. In physics, time is modeled as a parameter or dimension; in philosophy of mind, identity is treated as either narrative, psychological, or eliminable. These approaches operate at different explanatory levels without a shared ontological framework. (...) This paper proposes a structural reinterpretation of time and identity within the Three-Circle Ontology, a meta-ontological framework that distinguishes between foundational reality (Source), structured possibility (Code), and rendered experience (Projection). Within this framework, time is not treated as a fundamental flowing entity but as an ordering function governing the rendering of experiential frames. Identity is not treated as a persisting substance but as a continuity effect generated by interpretive and memory-based mechanisms within the projection domain. The paper develops a non-reductive account in which temporal succession and identity persistence are explained as features of rendering dynamics rather than intrinsic properties of reality. This approach allows time to be neither strictly objective nor purely subjective, and identity to be neither essential nor illusory. Instead, both are modeled as structurally emergent within constrained experiential systems. The scope of this work is explicitly ontological and conceptual. It does not advance new physical theories, empirical claims, or metaphysical doctrines. Its contribution lies in offering a coherent framework for analyzing time and identity across physics, philosophy, and cognitive science without collapsing distinctions between foundational structure and experiential appearance. (shrink)

Time is often treated either as a continuous coordinate in physical equations or as a global ordering whose arrow is explained by statistical mechanics, cosmology, or boundary conditions. FDS-O2 gives a narrower operational account: for a finite physical observer, usable time is the ordered structure of irreversible distinction updates in finite records. Building on FDS-O1, where an observer is defined as a finite distinction-register and measurement as stable record formation, this paper defines a temporal register as a physical (...) system that records, orders, timestamps, updates, synchronizes, and reuses distinctions under finite memory, finite clock precision, finite buffering, finite communication bandwidth, finite latency, and finite thermodynamic budgets. The central claim is not that coordi- nate time is unreal or that microscopic dynamics must be nonunitary. It is that finite systems access temporal order only through register time: causal dependencies, clock labels, logs, residues, and up- date traces carried by finite records. We make causal dependency prior to temporal labeling: record zj is operationally after zi when the update that forms zj depends on zi through an accessible finite update chain. When finite memory forces overwrite, compression, projection, or garbage collection, the update map is many-to-one. Its non-injectivity can be quantified by LU = H(X|Z), the residual set of compatible past states given the current record. This loss defines an operational arrow: future records may contain traces of past records, but erased distinctions cannot be reconstructed from the current finite record without external memory. The paper adds synchronization bottlenecks between finite observers, latency-induced apparent causal inversion, finite clock coarse-graining, dissipative projection, and long-context temporal collapse in AI-like finite-window systems. Deterministic sim- ulations illustrate memory-fill-driven non-injectivity, fixed-memory overwrite versus append-only logging, latency-based order inversion, clock-tick collisions, synchronization ambiguity, projection- semigroup loss, and context-window temporal collapse. The paper does not solve the cosmological arrow of time, the Past Hypothesis, the full Second Law, general relativity, or quantum measure- ment. Its contribution is narrower: it converts finite record formation into a concrete operational model of time as causal, irreversible, finite-register update. (shrink)

This article argues that existing approaches to programming ethical AI fail to resolve a serious moral-semantic trilemma, generating interpretations of ethical requirements that are either too semantically strict, too semantically flexible, or overly unpredictable. This paper then illustrates the trilemma utilizing a recently proposed ‘general ethical dilemma analyzer,’ GenEth. Finally, it uses empirical evidence to argue that human beings resolve the semantic trilemma using general cognitive and motivational processes involving ‘mental time-travel,’ whereby we simulate different possible pasts and futures. (...) I demonstrate how mental time-travel psychology leads us to resolve the semantic trilemma through a six-step process of interpersonal negotiation and renegotiation, and then conclude by showing how comparative advantages in processing power would plausibly cause AI to use similar processes to solve the semantic trilemma more reliably than we do, leading AI to make better moral-semantic choices than humans do by our very own lights. (shrink)

The Principle of Alternative Possibilities is the intuitive idea that someone is morally responsible for an action only if she could have done otherwise. Harry Frankfurt has famously presented putative counterexamples to this intuitive principle. In this paper, I formulate a simple version of the Principle of Alternative Possibilities that invokes a course-grained notion of actions. After warming up with a Frankfurt-Style Counterexample to this principle, I introduce a new kind of counterexample based on the possibility of time travel. (...) At the end of the paper, I formulate a more sophisticated version of the Principle of Alternative Possibilities that invokes a certain fine grained notion of actions. I then explain how this new kind of counterexample can be augmented to show that even the more sophisticated principle is false. (shrink)

The concept of branching time is widely utilized to counter fatalistic arguments to the conclusion that whatever will happen is already unavoidable. The most common semantics for branching time, such as Ockhamism, Peirceanism, and Supervaluationism, offer a formal explanation for why fatalistic arguments are flawed. This paper explores a different type of argument, one that borders on fatalism and is concerned with what might possibly happen in the future. In the paper, I show how this type of argument (...) poses a new fatalistic threat to branching time. (shrink)

Externalist theories of time claim that temporal properties exist independently of experience. This paper demonstrates that such theories fail by their own compositional standards. Materialism requires that all properties either be fundamental physical properties or compose from them. However, temporal properties (before/after relations, directedness, duration) cannot be built from non-temporal physical properties without presupposing the temporal structure being explained. This composition failure is not merely empirical but logical. Additionally, standard definitions of time as "change in physical states" involve (...) circular reasoning, as change itself presupposes temporal ordering. After demonstrating these failures, I show that experiential temporality, understood as limitation structure intrinsic to experience, provides a more coherent and epistemically grounded alternative. The apparent objectivity of time stems from shared experiential regularities and coordinating mechanisms, not from accessing external temporal dimensions. (shrink)

This paper extends the temporal concept of Sequential Time Theory (STT) to the problem of metrology in the quantum domain. In STT, a time interval Δt is constructed by a counter n representing the number of realizations of a standard displacement ΔQ_unit, while time t serves as a coordinate label assigned to this sequence. STT explicitly posits that "time is a scaling of physical change" and that "time is constructed solely by clock phenomena subject to (...) the same conditions within a local system." Consequently, in regimes where ΔQ is indistinguishable, time does not "cease to exist" but becomes "unconstructible (undefined)." Based on these definitions and axioms, this paper (i) organizes criteria for distinguishing between science and metaphysics, (ii) identifies conceptual confusions arising from the implicit assumption of an external classical clock in quantum theory, and (iii) proposes a relativity principle regarding differences in observation scale (e.g., macroscopic observation of microscopic systems). We demonstrate that issues such as measurement, classicality, and tunneling time can be unifiedly organized as problems of "choice of clock (ΔQ)" and "recording (event-token) protocols.". (shrink)

The direction of time is considered a fundamental yet unresolved problem in physics. While most fundamental equations are time-reversal symmetric, world nevertheless appears factually irreversible: structures emerge, bind existence, and cannot be undone in any real sense without losing their own conditions. Common explanations locate the direction of time in the entropic arrow, in cosmological initial conditions, or in emergent dynamics, without clarifying why world itself is not backward-viable. The present contribution proposes an ontological shift in perspective. (...) Time is not directed because physical processes are irreversible; rather, it is directed because world itself emerges in a directed manner. World formation is understood as a pre-ontological process in which possibility is condensed into viable existence. This condensation generates irreversible bindings—embodiment, relationality, and historical fixation—that cannot be undone without residue. The direction of time is the imprint of this binding. From this perspective, time does not appear as a neutral parameter but as the effect of recurrent opening against complete condensation. It marks the space of possibility of life. Without a direction of time, there would be stable states, but no emergence, no condensation of complexity, no being in a living sense. This ontological reading allows boundary concepts such as time travel or stable wormholes to be reassessed. They fail not because of technical deficits or logical paradoxes, but because they presuppose transportable, world-independent existence. The contribution does not formulate a physical model of time, but clarifies the ontological conditions under which the direction of time can meaningfully be addressed. -/- This paper functions as an interface text within a larger operator-based research corpus. Core concepts are applied here, not re-derived. The underlying research operates in a non-linear, rhythmically recursive epistemic mode grounded in an autistic form of structural perception; the present text provides an interface translation for academic contexts. (shrink)

This thesis focuses on two related though different topics: first, the metaphysics of dispositions; second, the relation between dispositionalism and time. For this reason, the thesis is divided in two main parts: the first part concerns the first topic, and the second part concerns the second. The aim of the project is to argue that dispositionalism faces two different problems: first, there is no viable metaphysics for dispositional properties; second, there is no viable theory of time that can (...) fit in a dispositional framework. (shrink)

Many philosophers hold that ‘one-instant worlds’—worlds that contain a single instant—fail to contain time. We experimentally investigate whether these worlds satisfy the folk concept of time. We found that ~50% of participants hold that there is time in such worlds. We argue that this suggests one of two possibilities. First, the population disagree about whether at least one of the A-, B-, or C-series is necessary for time, with there being a substantial sub-population for whom the (...) presence of neither an A-, B-, nor C-series, is necessary for time, and hence those folk have a radically more minimal concept of time than has been attributed to them by philosophers. Or, second, the population do not disagree about whether at least one of the A-, B-, or C-series is necessary for time, but disagree about what it takes for a world to fail to contain even a C-series. (shrink)

This paper does not challenge the observational fact of LIGO’s gravitational-wave detections. Instead, it examines a maximal interpretation often associated with those detections: that LIGO strongly supports the physical reality of spacetime and thereby naturally motivates a four-dimensional ontology. Using the audit vocabulary of STT-CR, the paper reformulates the LIGO case in terms of the relation among observable output OOO, measurement protocols PPP, calibration structure CCC, and theoretical variables Θsys\Theta_{\mathrm{sys}}Θsys. Within STT-CR, explanatory accountability is carried by the map (Θsys,P,C)→O(\Theta_{\mathrm{sys}},P,C)\to O(Θsys,P,C)→O, (...) while elements that do not participate in this map are treated as OverΘ\ThetaΘ. The paper shows that both general relativity and Sequential Time Theory can, at the level of the LIGO observational core, be cast as isomorphic observation maps. On the STT side, time is defined as an accumulation of local state-transitions, allowing the interferometric phase difference to be reconstructed without assuming that a four-dimensional spacetime ontology is observationally mandatory. The conclusion is limited but precise: LIGO strongly supports the predictive core of general relativity, yet LIGO data alone do not uniquely force a block-universe interpretation. (shrink)