Question

Write a essay on time travel

Answer 1

Time travel is a concept that humans are drawn to, largely because of the perceived impossibilities within it. In this essay I argue that all the perceived problems are valid, but are not arguments against time travel.

One dimensional time travel is that by which actions in the past bring about events so that the future plays out the way that you remember it occurring.

Two dimensional time travel is that which changes the past, taking a possible world and bringing it into existence, creating branching timelines.

They are very distinct, in that one dimensional time travel does not involve disrupting the history as the time traveler knows it, whereas two dimensional time travel ‘creates’ a new alternate reality/timestream which can range anywhere from being almost identical to bearing little resemblance to the time traveler’s remembered reality.

In this respect, two dimensional time travel is less time travel in the traditional respect, and more space travel, and so this essay shall deal henceforth with one dimensional time travel.

I believe that one dimensional time travel is logically possible, because of the fact that there are no contradictions in our explanations of time travel, and because we can conceive of a coherent world where some of the people we interact with are time travelers from the future, and where we might in future go back to the past and interact there.

However, at first glance there appear to be a number of conceptual impossibilities with one dimensional time travel, and here I will discuss and resolve these, explaining why they are not, as they first appear, an argument against time travel.

Conceptual impossibilities within time travel range from those concerning personal identities to causal loops to the Grandfather Paradox, and I’ll present them as such.

As David Lewis talks about in his “The Paradoxes of Time Travel[1], there are a few concepts with personal identity that can be hard to grasp; in particular the idea of having two of the same person in the one place. The problem there arises because of the lack of clarity surrounding personal identity.

It’s hard enough to come to terms with how we know a person, let us say Mary, is the same person when she wakes up each day as when she went to sleep. Adding time travel into the equation only increases the complexity, and hence the vanishing/appearance of Mary at different points in time – how do we know Mary in 1992 is the same person as Mary in 1301?

At this point it seems sensible to define what we mean by ‘person-stage’; the state of a person at a particular point in their personal time.

E.g. Joe at 5 years is a different ‘person-stage’ to Joe at 10 years.

I will continue in the comments section