This article discusses The Travelling Players (1975), Theo Angelopoulos's provocative film, by upholding the priority the director's audio-visual images assign to the future as what Deleuze calls ‘the pure and empty form of time’. It also argues that The Travelling Players supplements the Deleuzian quartet of crystal-images with a new type of crystal-image: Angelopoulos crafts images of extraordinary consistency that act as filters, splitting and sieving time at once, a kind of audio-visual refinery laid out on (...) the silver screen, with the distillation process dedicated to blocking repression, its past and present iterations, from contaminating the yet-to-come, banishing the negative from returning in the future. (shrink)

This article explores how ‘biology’ — in the sense that bodies are increasingly understood in biological terms, from the molecular to the species level — is becoming more central in the recognition of political worth, and I argue that humanitarians are key players in producing this reality. I focus on the role biology plays in the politics of immigration. Combining ethnographic research with undocumented immigrants in Paris and asylum claimants in the US, I examine how biology has become a (...) central tool in the ability to travel. How did pathology (i.e. illness) or violations of anatomy (i.e. torture, sexual violence) become the ‘best’ ways to get papers as an undocumented immigrant — better than selling one’s labor power? I suggest that biological evidence — of illness, of torture, of immunity levels — are used as key measurements of suffering, which justifies humanitarian exceptions, in this case, for papers. My argument is that there is a dual regime of truth at work, where the multiple ontologies of biology get reduced to one epistemology of biology as ‘fixed’ when it concerns immigrants and refugees, due to the role of humanitarianism in the politics of immigration. This is explored in the context of profound inequalities between those in the global North and South, asking how the hope offered by biological evidence takes on different meanings and consequences depending on one’s position in the global matrix of wealth and poverty, race and gender. (shrink)

We consider a special case of heuristics, namely numeric heuristic evaluation functions, and their use in artificial intelligence search algorithms. The problems they are applied to fall into three general classes: single-agent path-finding problems, two-player games, and constraint-satisfaction problems. In a single-agent path-finding problem, such as the Fifteen Puzzle or the travelling salesman problem, a single agent searches for a shortest path from an initial state to a goal state. Two-player games, such as chess and checkers, involve an adversarial (...) relationship between two players, each trying to win the game. In a constraint-satisfaction, problem, such as the 8-Queens problem, the task is to find a state that satisfies a set of constraints. All of these problems are computationally intensive, and heuristic evaluation functions are used to reduce the amount of computation required to solve them. In each case we explain the nature of the evaluation functions used, how they are used in search algorithms, and how they can be automatically learned or acquired. (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)

In this paper I defend two conclusions: that time travel journeys to the past are not undertaken freely and, more generally, that nobody is free between the earliest arrival time and the latest departure time of a time travel journey to the past. Time travel to the past destroys freedom on a global scale.

I start off by relating the standard philosophical account of what time travel is to models of time travel that have recently been discussed by physicists. I then discuss some puzzles associated with time travel. I conclude that philosophers’ arguments against time travel are relevant when assessing the likelihood of the occurrence time travel in our world, and are relevant to the assessment whether time travel is physically possible.

Jewish Travel in Antiquity. By Catherine Hezser. Texts and Studies in Ancient Judaism, vol. 144. Tübingen: Mohr Siebeck, 2011. Pp. x + 529. €139.

The cinema of Theo Angelopoulos is celebrated as challenging the status quo. From the political films of the 1970s through to the more existential works of his later career, Vrasidis Karalis argues for a coherent and nuanced philosophy underpinning Angelopoulos' work. The political force of his films, including the classic The Travelling Players, gave way to more essayistic works exploring identity, love, loss, memory and, ultimately, mortality. This development of sensibilities is charted along with the key cultural moments (...) informing Angelopoulos' shifting thinking. From Voyage to Cythera until his last film, The Dust of Time, Angelopoulos' problematic heroes in search of meaning and purpose engaged with the thinking of Plato, Mark, Heidegger, Arendt and Luckacs, both implicitly and explicitly. Theo Angelopoulos also explores the rich visual language and 'ocular poetics' of Angelopopulos' oeuvre and his mastery of communicating profundity through the everyday. Karalis argues for a reading of his work that embraces contradiction and celebrates the unsettling questions at the heart of his work. (shrink)

Time travel is metaphysically possible. Nikk Effingham contends that arguments for the impossibility of time travel are not sound. Focusing mainly on the Grandfather Paradox, Effingham explores the ramifications of taking this view, discusses issues in probability and decision theory, and considers the potential dangers of travelling in time.

_Counterpath_ is a collaborative work by Catherine Malabou and Jacques Derrida that answers to the gamble inherent in the idea of "travelling with" the philosopher of deconstruction. Malabou's readerly text of quotations and commentary demonstrates how Derrida's work, while appearing to be anything but a travelogue, is nevertheless replete with references to geographical and topographical locations, and functions as a kind of counter-Odyssey through meaning, theorizing, and thematizing notions of arrival, drifting, derivation, and catastrophe. In fact, by going straight (...) to the heart of the Derridean idea of "spacing," she finally makes it seem as though Derrida has never written about anything but travel. Malabou's text is punctuated by a series of postcards received by Derrida from destinations such as Istanbul and Porto, Laguna Beach and Athens, which are inspired by his reading of her evolving discussion. Writing in a familiar and unguarded manner, as if he were "on vacation" from his own writing, Derrida still remains totally faithful to that work and invites the reader to reflect on much of what haunts his texts as well as his daily life, questions of distance and death, the relation to the other, and exile. (shrink)

The paper is devoted to modelling of cell differentiation in an initially homogeneous cell population. The mechanism which provides coexistence of two cell lineages in the initially homogeneous cell population is suggested. If cell differentiation is initiated locally in space in the population of undifferentiated cells, it can propagate as a travelling wave converting undifferentiated cells into differentiated ones. We suggest a model of this process which takes into account intracellular regulation, extracellular regulation and different cell types. They include (...) undifferentiated cells and two types of differentiated cells. When a cell differentiates, its choice between two types of differentiated cells is determined by the concentrations of intracellular proteins. Differentiated cells can either stimulate differentiation into their own cell lineage or into another cell lineage. In the case of the positive feedback, only one lineage of differentiated cells will finally appear. In the case of negative feedback, both of them can coexist. In this case a periodic spatial pattern emerges behind the wave. (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)

It is clearly stated what time-travel would be, were it possible, and it is thereby shown that the very concept of time-travel is incoherent.

Over the last several decades, slow travel has been garnering increasing attention, especially with regards to the climate crisis and the many harms that result from global tourism. The defenders of slow travel claim that traveling slowly benefits not only the environment but also the local communities most affected by tourism, as well as the travellers themselves. This kind of defence, while seeming to be intuitively correct, is missing a sustained argument that explains why this is the case. In this (...) paper, we fill this explanatory gap by relying on philosopher Albert Borgmann’s theory of devices and focal practices to provide a theoretical ground for the claims made about traveling fast and slow. (shrink)

The “transnational turn” in ethnic studies, women’s studies and American studies has shifted the discussion of identity by focusing on the space-between, the liminal space that emerges as a starting point of reflecting on one’s varied social locations.1 In this essay, I would like to theorize the philosophical underpinnings of identity formation and the social ontology of transnational identities through the works of Josiah Royce. In theorizing about the betweenness relation, I examine two concepts in Royce’s work—travel and home—in order (...) to interpret Royce’s motivations and interests in conceiving his theory of community and provincialism. In this essay, I articulate the two requirements of the betweenness.. (shrink)

The article traces the origin and development of the concept of social skills in first and foremost American academic discourse. As soon as the concept of social skills was coined, the concern for people lacking such skills started and has been on the increase ever since. After the analysis of the academic history of the concept follows an examination of the implementation of a range of assessment instruments and training programmes related to social skills in contemporary Danish welfare institutions. The (...) analysis forwarded in the article thus demonstrates how an intellectual idea may develop and travel - and on its journey connect to pre-existing cultural logics and societal concerns. The idea of social skills has through its development been made uncontroversial – everybody wants to be skilful. The concept does, however, convey an individualistic view on social life and imposes a reflexivity over own performance on the participants. Further, its normative character contributes to a problematization of those who are perceived to lack these skills. (shrink)

Existing puzzles about coinciding objects can be divided into two types, corresponding to the manner in which they bear upon the endurantism v. perdurantism debate. Puzzles of the first type, which involve temporary spatial co-location, can be solved simply by abandoning endurantism in favor of perdurantism, whereas those of the second type, which involve career-long spatial co-location, remain equally puzzling on both views. I show that the possibility of backward time travel would give rise to a new type of puzzle. (...) The new puzzles confront perdurantists and can be solved just by shifting to endurantism. (shrink)

We standardly evaluate counterfactuals and abilities in temporally asymmetric terms—by keeping the past fixed and holding the future open. Only future events depend counterfactually on what happens now. Past events do not. Conversely, past events are relevant to what abilities one has now in a way that future events are not. Lewis, Sider and others continue to evaluate counterfactuals and abilities in temporally asymmetric terms, even in cases of backwards time travel. I’ll argue that we need more temporally neutral methods. (...) The past shouldn’t always be held fixed, because backwards time travel requires backwards counterfactual dependence. Future events should sometimes be held fixed, because they’re in the causal history of the past, and agents have evidence of them independently of their decisions now. We need temporally neutral methods to maintain connections between causation, counterfactuals and evidence, and if counterfactuals are used to explain the temporal asymmetry of causation. (shrink)

In this paper I borrow from Maria Lugones’ work on playful “world-traveling” and W.E.B. Du Bois’ notion of “double consciousness” to make the case that humor can facilitate an openness and cooperative attitude among an otherwise closed, even adversarial audience. I focus on what I call “subversive” humor, that which is employed by or on behalf of those who have been continually marginalized. When effectively used, such humor can foster the inclination and even desire to listen to others and, if (...) only for brief moments, adopt their point of view. To be able to see oneself as others see you can also be a desirable capacity, because along with such multidimensional seeing comes an epistemic advantage lacking in those who have no need nor desire to see as others do, especially if the vision of the others happens to be from below where one perceives that the promises of our explicit ideals are constantly being implicitly broken. Such humor is aesthetic, pleasurable in and of itself, and not amenable to scientific dissection. But it is also a skill that can be honed into a powerful tool of persuasion in circumstances where straightforward arguments are less effective. It can raise consciousness about the lived experiences of those suffering under systemic oppression and foster world travelling. Subversive humor encourages audiences, especially those who contribute to what Jean Harvey calls “civilized oppression”, to playfully travel across worlds and “tarry along” with the perspectives of the marginalized. (shrink)

This article explores Gypsy Travellers' changing views on their children's education. It highlights the positive means some schools use to encourage greater involvement of Gypsy Traveller parents. It argues that current educational policy needs to be re-developed to incorporate more effective and affirmative responses to interrupted and nomadic learning. It draws heavily on interviews with Gypsy Traveller families in an effort to give 'voice' to an under-represented community.

This paper examines understandings of community and safety for Gypsy, Roma and Traveller (GRT) groups in schools in a metropolitan borough. One school in particular was identified as being the 'Gypsy school' and was attended by the majority of GRT children in the borough. The school was recognised as a model of 'good practice' reflecting its holistic approach towards the GRT community but it was also successful for wider reasons. A picture of the intersection of different communities emerged from interview (...) accounts in which a GRT community with strong local attachments, socially negotiated and maintained, figured very strongly. The GRT community was also identified as sharing racist attitudes towards other non-white immigrants. This article examines children's perspectives of their engagement with the education process and how the strong GRT community played an important part in their understandings of safety and belonging. (shrink)

Ryan Wasserman explores a range of fascinating puzzles raised by the possibility of time travel, with entertaining examples from physics, science fiction, and popular culture, and he draws out their implications for our understanding of time, tense, freedom, fatalism, causation, counterfactuals, laws of nature, persistence, change, and mereology.

There is a growing body of scholarship that is addressing the ethics, in particular, the bioethics of space travel and colonisation. Naturally, a variety of perspectives concerning the ethical issues and moral permissibility of different technological strategies for confronting the rigours of space travel and colonisation have emerged in the debate. Approaches ranging from genetically enhancing human astronauts to modifying the environments of planets to make them hospitable have been proposed as methods. This paper takes a look at a critique (...) of human bioenhancement proposed by Mirko Garasic who argues that the bioenhancement of human astronauts is not only functional but necessary and thus morally permissible. However, he further claims that the bioethical arguments proposed for the context of space do not apply to the context of Earth. This paper forwards three arguments for how Garasic’s views are philosophically dubious: (1) when he examines our responsibility towards future generations he refers to a moral principle (which we will call the principle of mere survival) which, besides being vague, is not morally acceptable; (2) the idea that human bioenhancement is not natural is not only debatable but morally irrelevant; and (3) it is not true that the situations that may arise in space travel cannot occur on Earth. We conclude that not only is the (bio)enhancement of humans on Earth permissible but perhaps even necessary in certain circumstances. (shrink)

Role is a commonly used concept in software development, but a concept with divergent definitions. This paper discusses the characteristics of roles in software organizations, and contrasts such organization roles with other player-centric conceptions. Roles in organizations have their own identity and do not depend on role players for their existence. In software terms, such roles are first-class runtime entities rather than just design concepts. We define characteristic properties of both roles and players in organizational contexts, and show (...) how the boundary between a role and its player varies depending on the level of autonomy the player is allowed. We show how roles can facilitate the separation of structure from process facilitating greater adaptivity in software. The problem of preservation of state in role-based organizations is also discussed. Possible implementation strategies for both roles and players are discussed and illustrated with various role-oriented approaches to building software organizations. (shrink)

In no possible world does a time traveler succeed in killing herearlier self before she ever enters a time machine. So if many,many time travelers went back in time trying to kill theirunprotected former selves, the time travelers would fail inmany strange, coincidental ways, slipping on bananapeels, killing the wrong victim, and so on. Such cases producedoubts about time travel. How could ``coincidences'' beguaranteed to happen? And wouldn't the certainty of coincidentalfailure imply that time travelers are not free to killtheir (...) earlier selves? But if so, what would inhibit theirfreedom? Despite initial appearances, these and other doubtsmay be answered: the possibility of time travel survives yetanother challenge. (shrink)

It has sometimes been suggested that backwards time travel always incurs causal loops. I show that this is mistaken, by describing worlds where backwards time travel occurs and yet no causal loops occur. Arguments that backwards time travel can occur without causal loops have been given before in the literature, but I show that those arguments are unconvincing.

Many defenders of the possibility of time travel into the past also hold that such time travel places no restrictions on what said time travelers can do. Some hold that it places at least a few restrictions on what time travelers can do. In attempting to resolve this dispute, I reached a contrary conclusion. Time travelers to the past cannot do other than what they in fact do. Using a very weak notion of can, I shall argue that the correspondingly (...) strong cannot do otherwise applies in the case of backwards time travel. I defend this result from objections. (shrink)

There is an extensive literature on time travel in both philosophy and physics. Part of the great interest of the topic stems from the fact that reasons have been given both for thinking that time travel is physically possible—and for thinking that it is logically impossible! This entry deals primarily with philosophical issues; issues related to the physics of time travel are covered in the separate entries on time travel and modern physics and time machines. We begin with the definitional (...) question: what is time travel? We then turn to the major objection to the possibility of backwards time travel: the Grandfather paradox. Next, issues concerning causation are discussed—and then, issues in the metaphysics of time and change. We end with a discussion of the question why, if backwards time travel will ever occur, we have not been visited by time travellers from the future. (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)

Research on video game violence has focused on the impact of aggression, but has so far neglected the processes and mechanisms underlying the enjoyment of video game violence. The present contribution examines a specific process in this context, namely players' strategies to cope with moral concern that would arise from violent actions. Based on Bandura's theory of moral disengagement, we argue that in order to maintain their enjoyment of game violence, players find effective strategies to avoid or cope (...) with the moral conflict related to their violent behaviors in the game world. Exploratory interviews with ten players of violent video games revealed some relevance of moral reasoning to their game enjoyment, and several strategies that help players to ‘manage’ moral concern. Most importantly, respondents referred to the game-reality distinction and their focus on winning the game when explaining how violent action is a by-product of good performance. Findings are discussed in light of further theorizing on ‘moral management’ and potential links to the media violence debate. (shrink)

This paper suggests a way of formalizing the amount of information that can be conveyed to each player along every possible play of an extensive game. The information given to each player i when the play of the game reaches node x is expressed as a subset of the set of terminal nodes. Two definitions are put forward, one expressing the minimum amount of information and the other the maximum amount of information that can be conveyed without violating the constraint (...) represented by the information sets. Our definitions provide intuitive characterizations of such notions as perfect recall, perfect information and simultanetty. (shrink)

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 time travel and spatial location.

Some say that presentism precludes time travel into the past since it implies that the past does not exist, but this is a bad argument. Presentism says that only currently existing entities exist, and that the only properties and relations those entities instantiate are those that they currently instantiate. This does in a sense imply that the past does not exist. But if that precluded time travel into the past, it would also preclude the one-second-per-second “time travel” into the future (...) that is ordinary persistence, for presentism accords the future the same ontological status as the past. Instead of quantifying over past and future objects and events, presentists speak a tensed language, regimented with primitive sentential tense operators. For a presentist, a persisting person is one who did exist, and who will exist. Regimented, these claims become: it was the case that she exists, and it will be the case that she exists. The presentist may then apply the same strategy to time travel proper. Suppose Katy travels back to the time of the dinosaurs. The presentist can say that it was the case two hundred million years ago that Katy exists. This claim, which consists of a present-tense statement “Katy exists” embedded within the past tense operator it was the case two hundred million years ago that, is exactly the sort of statement about time that a presentist is free to accept. This has all been made clear by Simon Keller and Michael Nelson ( ). In addition to rebutting the bad argument against the consistency of presentism and time travel, Keller and Nelson argue positively in favor of consistency by showing how to translate David Lewis’s ( ) account of time travel into the presentist’s tensed language. The appearance of con ict between presentism and time travel, they argue, is due only to the fact that most defenders of time travel (for example Lewis) have tended to phrase their defenses in nonpresentist terms. As much as I applaud their rebuttal of the bad argument, I wish to sound a note of caution.. (shrink)

We consider T -round elimination tournaments where players have fixed resources instead of cost functions. We show that players always spend a higher share of their resources in early than in later rounds in a symmetric equilibrium. Equal resource allocation across T rounds takes place only in the winner-take-all case. Applications for career paths, elections, and sports are discussed.

FIFA President Sepp Blatter’s recent attempt to resurrect the 6 + 5 quota for club football which limits the number of home-grown players to six is a protectionist measure at odds with global trends in free trade and freedom of movement. We remain unconvinced that his goals—to arrest the decline in the competitive quality and balance of international football, ensure greater investment in developing native talent and safeguarding national identity—are a problem or served well by such a regulation. We (...) show that the impact of foreign players on national teams is mixed and restrictions are as likely to undermine the quality of national teams as much as they will improve them. Our moral case will show he is wrong to assert that elite club football’s prime agenda ought to be a nationalist one. We conclude that the primary threat to the integrity, competitive balance and cultural significance of football is not labour migration but misplaced financial imperatives that have an overriding impact on shaping footba.. (shrink)

This paper focuses on problems for time travel that specifically concern continuous time-travel to the past, problems to do with potential collisions with past obstacles such as former time-slices of the time traveler herself. These problems have not been discussed nearly as much as other questions about time travel, such as the Grandfather Paradox. Here I focus on discussions by Bernstein, Dowe, Grey and Le Poidevin. After examination, I conclude that only the problems of turning around in time have any (...) merit and present a new proposal of my own for turning around in time without collisions. I assume a Lewisian framework throughout. (shrink)

An ability to accurately recognize negative emotions in others can initiate pro-social behavior and prevent anti-social actions. Thus, it remains of an interest of scholars studying effects of violent video games. While exposure to such games was linked to slower emotion recognition, the evidence regarding accuracy of emotion recognition among players of violent games is weak and inconsistent. The present research investigated the relationship between violent video game exposure and accuracy of negative emotion recognition. We assessed the level of (...) self-reported VVGE in hours per day and the accuracy of the recognition using the Facial Expressions Matching Test. The results, with adolescents and with adults, showed that VVGE was negatively related to accurate recognition of negative emotion expressions, even if controlled for age, gender, and trait empathy, but no causal direction could be assessed. In line with the violent media desensitization model, our findings suggest that higher self-reported VVGE relates to lower recognition of negative emotional expressions of other people. On the one hand, such lower recognition of negative emotions may underlie inaccurate reactions in real-life social situations. On the other hand, lower sensitivity to social cues may help players to better focus on their performance in a violent game. (shrink)

A testimony is somebody else’s reported experience of what has happened. It is an indispensable source of knowledge. It only gives us historical cognition, however, which stands in a complex relation to rational or philosophical cognition: while the latter presupposes historical cognition as its matter, one needs the architectonic “eye of a philosopher” to select, interpret, and organize historical cognition. Kant develops this rationalist theory of testimony. He also practices it in his own work, especially while theorizing about race as (...) a subject of natural philosophy. In three dedicated essays on this subject, he treats race from the standpoint of a philosophical investigator of nature (Naturforscher), who (as Kant puts it in the first Critique) learns from nature “like an appointed judge who compels witnesses to answer the questions he puts to them.” This view underwrites Kant’s use of travel reports (a type of testimony) in developing and defending his theory of race. (shrink)