Online research in philosophy

In the present paper, I offer a new argument to show that presentism about time is incompatible with time travel. Time travel requires leaving the present, which, under presentism, contains all of reality. Therefore to leave the present moment is to leave reality entirely; i.e. to go out of existence. Presentist “time travel” is therefore best seen as a form of suicide, not as a mode of transportation. Eternalists about time do not face the same difficulty, and time travel is compossible with eternalism.

Humans have long been fascinated by the idea of visiting the past and of seeing what the future will bring. Time travel has been one of the most popular themes of science fiction. Most people have seen the TV series ‘Dr Who’ or ‘Quantum Leap’ or ‘Star Trek’. You’ve probably seen one of the ‘Back to the Future’ or ‘Terminator’ movies, or ‘Twelve Monkeys’. Time travel narratives provide fascinating plots, which exercise our imaginations in ever so many ways. But is the idea of travelling forward and backward in time pure fantasy—or can it be done? To be sure, not all time travel scenarios are coherent. But we hope to persuade you that the most common objections to the very idea of time travel have no real force.

Many philosophers say that time involves a kind of passage that distinguishes it from space. A traditional objection is that this passage would have to occur at some rate, yet we cannot say what the rate would be. The paper argues that the real problem with time’s passage is different: time would have to pass at one second per second, yet this is not a rate of change. This appears to refute decisively not only the view that time passes, but any tensed theory of time.

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.

Part I: Dimensions of time's enigma -- Is time real? -- Eleaticism, temporality, and time -- The makings of a temporal universe -- Pastness and futurity -- Synchronicity and synchronicity -- Temporal pace and measurement -- Presentness or the present -- Aristotle's real account of time -- Parmenidean time and the impossible now -- Cosmic motion and the speed of time -- Time as the motion of the cosmos -- Time as the cosmos itself -- Time as motion and all change -- Temporal cognition and the return of the now -- Real temporality in an Aristotelian world -- Does Aristotle refute eleaticism? -- Bisection argument I -- Bisection argument II -- Bisection argument III -- Plotinus' vitalistic platonism and the real origins of time -- Temporality, eternality, and Plotinus' new metaphysic -- Plotinus' critique of Aristotelian motion -- Indefinite temporality and the measure of motion -- Plotinus' neoplatonic account of time.

The aim of Jonathan Tallant’s recent article ‘What is B-time?’ (2007) is to demonstrate that B-time - which holds that time consists solely of tenseless temporal relations - is something of which we have no understanding, and that, therefore, if mind-independent time is B-time, then time is unreal. Of course, implicit in his own position is that since time is plausibly real and we do understand what time is, the correct ontology of time is A-time or tensed time. How then does Tallant purport to substantiate the crucial claim that ‘we have no understanding of what “B-time” is’ (2007: 147)? The overall structure of his argument may be stated as follows:1 Argument A..

The most grandiose of the many philosophical problems of time is whether it is real or not. An example of a metaphysical argument to the effect that time is unreal is that of the idealist F.H. Bradley. In setting forth his case he made a distinction between 1) time as space-like and 2) time "as presented,� the "now.�

In this course we will examine several philosophical puzzles concerning time. We all seem to experience time in a very fundamental and direct way. Yet once we begin to reflect on what time really is, it is easy to feel as puzzled as St Augustine was, who wrote: “If no one asks me, I know what [time] is. If I wish to explain it to him who asks me, I do not know.” The first set of issues we will discuss concern the question whether time is ‘real.’ Time appears to consist of past, present and future. But do the past and the future exist in the same way as the present or is only the present real? Does time ‘flow’? In what ways is time different from space? What would it be to ‘spatialize’ time? Next we will ask whether certain views of time imply that there can be no freedom of the will. One might worry that if facts about the future (including facts about what I will do tomorrow) already existed in the same way as facts about the present exist, then I could not be free to choose what I will do. After all, how can I be free to decide to skip class tomorrow, if it is ‘already’ a fact today that I will attend class? What, if anything, is the connection between various views of time and ‘fatalism’? The third topic we will discuss is time travel. First we will ask whether time travel is a conceptual possibility. As we will see, there are certain conceptual puzzles associated with the possibility of time travel. For example, one might think that if time travel is possible, then I should be able to travel back in time and kill my father before the date of my conception. But this scenario seems to lead to a contradiction. Some have taken considerations such as these to argue that the very idea of time travel is incoherent. Is this right? If not, why not? Then we will look at what the theory of relativity says about the nature of time in general and about the physical possibility of time travel more specifically. Finally we will examine several issues concerning the asymmetry of time..

The question of the existence and the properties of time has been subject to debate for thousands of years. This considered and complete study offers a contrastive analysis of phenomenologies of time from the perspective of the problematics of the visibility of time. Is time perceptible only through the veil of change? Or is there a naked presence of "time itself"? Or has time always effaced itself? McClure's new work also stages confrontations between phenomenology of time and analytical philosophy of time. By doing so he explores ancient issues from a fresh perspective, such as whether time passes, whether experimental time is "real time," and whether the very concept of time is contradictory.

This is a study of the nature of time. In it, redeploying an argument first presented by McTaggart, the author argues that although time itself is real, tense is not. He accounts for the appearance of the reality of tense - our sense of the passage of time, and the fact that our experience occurs in the present - by showing how time is indispensable as a condition of action. Time itself is further analysed, and Dr Mellor gives answers to most of the metaphysical questions it provokes, concerning the relation of time to space, the dissection of time, and its relation to change and causation.