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)

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.

This article addresses the critically neglected relation between Baedekers and nationalism, in order to articulate the reasons for the decline of the Baedeker empire in the early twentieth century. Conditions in the First World War undermined the Baedekers' foundational concepts of landscape description. Additionally, the guidebooks emblematized a lost pre-war style of international journey. However, evidence in unexplored archival and fictional sources qualifies our understanding of these changes. This article revisits and reconciles such assessments, by explaining how the war also (...) recast the Baedekers' mediation of international access as a form of nationalist expansionism, and hence a suspect project. (shrink)

Traveling-wave solutions of the standard and compound form of Korteweg–de Vries–Burgers equations are found using factorizations of the corresponding reduced ordinary differential equations. The procedure leads to solutions of Bernoulli equations of non-linearity 3/2 and 2 (Riccati), respectively. Introducing the initial conditions through an imaginary phase in the traveling coordinate, we obtain all the solutions previously reported, some of them being corrected here, and showing, at the same time, the presence of interesting details of these solitary waves that have been (...) overlooked before this investigation. (shrink)

He also tells a very interesting personal story of his battles to get these trajectories used, and how he was able to save the Hiten spacecraft and get it to the moon. This is a great story, and he tells it very well.

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)

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.

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.

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.

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)

Wealthy individuals have many adventures to choose from in today’s world, including visiting the moon and spending time in the deepest canyons of the ocean. But the most coveted waiting list is spo...

Most approaches to quantum gravity suggest that relativistic spacetime is not fundamental, but instead emerges from some non-spatiotemporal structure. This paper investigates the implications of this suggestion for the possibility of time travel in the sense of the existence of closed timelike curves in some relativistic spacetimes. In short, will quantum gravity reverse or strengthen general relativity’s verdict that time travel is possible?

In this essay I explore how travel and border-crossing for abortion care constitutes a challenge to methodological nationalism, which serves to obscure such experiences from view. Drawing up field research conducted at two abortion clinics in Albuquerque, New Mexico, I also explore some implications of regarding pregnant people who travel for abortion care as a type of migrant, even if they are U.S. citizens and legal residents. Finally, I assess how this discursive shift can make important contributions to (...) pandemic and migration ethics. (shrink)

Ce livre est, comme le titre l’indique, un objet hybride, à la fois dictionnaire et anthologie. L’auteur n’est pas une historienne professionnelle mais une écrivaine, déjà auteur d’une biographie d’une de ses aventurières, l’Anglaise Adela Breton, qui fut une pionnière des séjours et des relevés archéologiques à travers le Mexique précolombien à la fin du xixe siècle (Albuquerque, University of New Mexico Press, 2005). Chaque notice individuelle est suivie d’une indication de sources (parfois...

In his thought-provoking, carefully crafted, and impressively researched article, Don Scheid makes a compelling argument for an indefinite detention paradigm for “mega-terrorists.” Scheid's proposa...