#imagine my face when I realized pale latitude compressors might be able to allow faster than light travel

[visual-calc]

Say, does quantum physics correlate with time traveling journey? Time traveling machine quite tempting to be made..

VISUAL CALCULUS [Heroic: Success] — Quantum physics actually has very little to do with our understanding of time, or the possibility of time travel. Most of the relevant theory falls under the theory of relativity, with a little bit of thermodynamics sprinkled in.

At its most basic level, relativity states that our reality exists in four dimensions: the three spatial dimensions we usually think of, and time, which is why we sometimes refer to it as "spacetime". Time is connected to the other three dimensions in a special way: the faster you move through space, the slower you move through time. Similarly, the closer you are to very massive object, such as a black hole or Elysium's core, the slower time passes for you.

This means that it is almost trivially easy to travel forward in time— just steal an aerostatic and fly very, very fast, or take a vacation at the bottom of the ocean. Either of these will cause you to experience less time than a friend who stays stationary or at sea level, so upon your return you will have effectively traveled to the future— by a few billionths of a second. A difference in elevation of a few thousand feet is not enough to create a significant difference in time, nor are there any means of transportation able to reach the necessary speeds to make this a practical means of time travel. But traveling forward is at least theoretically possible.

However, based on your prior interaction with Savoir Faire and Interfacing, I suspect that you are interested in traveling backwards, and I am afraid I need to be the bearer of bad news: it is simply impossible. The arrow of time only points forward. This is a law higher than you, or me, or Authority, or any of us. There is nothing we can do to reverse it, in any normal reality.

Physically, this is intrinsically linked to the idea of entropy, a measure of disorder. Entropy can never decrease— any process that is possible can only increase disorder, never decrease it. Reversing the flow of time and traveling backwards through it would allow you to increase order. For example, if you broke a glass, then traveled back to a time where the glass was whole again, you would be returning it to its ordered state, making backwards time travel impossible just from a physics standpoint. That doesn't even scratch the surface of the possible paradoxes of causality such travel would cause.

However. Not all of Elysium is part of our normal sense of reality. Entropy and entroponetic share the same root, after all— the Pale is entropy incarnate, disorder made manifest. Deep enough in the Pale, this disorder is great enough that our usual notions of time and space have no meaning. Reality ceases to have dimensions at all and the laws of physics break down.

The only way we can travel through the Pale at all is using Pale latitude compressors— devices that allow us to force the Pale into having dimensions again, taking on the shape of our familiar four-dimensional spacetime. No one has ever tried forcing the pale into being anything else. It's easy to see why— for transport of human beings, you want to make sure that they stay cocooned in a reality they can safely exist in. But, I do confess to having wondered whether it might be possible to use a Pale latitude compressor to impose a different type of reality on the Pale. If we're imposing dimensions anyway, perhaps it's possible to pick how they relate to each other such that traveling backwards in time is possible?

Please do note that I do not recommend that you try this, Turtle. Harry's brief encounter with the latitude compressor in Martinaise has more than convinced me that they are not to be trifled with. Additionally, there's no telling whether a set of dimensions that would allow time travel would also allow you to exist, or whether such a set would even exist at all. Most of us have come to like you quite a lot— I would hate to see you perish as a result of an entroponetic accident because you tried to time travel.