This musing on time travel comes from notes that I jotted down in February of this year.  With the beginning of the illegitimate real estate developer presidency, my only way of making sense of this moment in America was to think of travelling back in time (What if Comey hadn't done that, What if those of us in Detroit had dedicated ourselves more to getting out the vote? etc).  

Also, I am interested in the limits of what might be relevant to architecture and possibly disciplined by architecture as a practice or way of thinking.   

Time travel becomes possible, and even vaguely within the realm of architecture, when we consider time as a series of material states. Planets move, cells divide, bodies respirate. These things occur in intervals.  Everything moves-- at some scale or in some condition.  Stasis demands excessive control. Time happens through the repeated patterns of matter. Planets don't just move, they orbit. Bodies respirate until they don't, then they die. In that order.

The possibility of traveling through time could be conceived as a reconstruction or full mediatization of a state of matter.

It we think of time as a vector of matter, time travel can be split into two distinct aspects or technologies: the archiving and the affecting.  I am not talking about the notion of travel that involves maintaining oneself as a body that inhabits two times at once. This notion of a coherent embodied self 'traveling' through time feels based on a geographic fantasy, a re-reading of flight and an extension of empire and colonialism. This is also, of course, the Time Machine of H. G. Wells from 1895 and much of science fiction since.  [Note-- I am ignoring "forward" time travel because that resolves itself simply in a medical imagination-- it would basically just involve freezing oneself for a certain amount of time and waking up 500 years or 1,000 years later.]

Here are some thoughts on an alternative to that time-travel-as-imperial-geography.  This other kind of time machine would operate as a mediatization of a state of matter.  It's easy to imagine virtual reality becoming more robust programmable matter.  We can already record 360 degree video and sound.  What about smell, taste, and touch?  MIT Media Labs is now consistently working on some form of archiving and mediatizing those 3 senses.  How much technology would it take for a moment to be fully perceptually archived and, thereby, downloadable? This enables time travel, in a sense, to any archived history.  In doing so, it also intensifies the paradox of the copy-- perhaps a mode of time machine portended in the Adorno-Benjamin debates more than 20th century science fiction.  Let's call this Machine A.

Above, Tastes Like Rain, a project from MIT Media Lab 2010 that coded data into taste. 

But an aspect of time travel involves not just witnessing or experiencing the past, but changing it.  Time travel means not just knowing another time period, but impacting it.  This would involve a different technology.  We could imagine them as connected or folded into one apparatus-- just as a music player is combined with your telephone, despite the former evolving from a phonograph.

Assuming that we have the aspect of archiving and mediatizing the past figured out -- say, that people in the year 2925 will have hyper-virtual reality access to a copied reality from 2025-- the question of affecting reality remains.  

Can the question of changing the past also be considered in terms of matter and media, ie storage and communication?

In a more narrative sense, if a group of sociologists in 2925 were very interested in some event from 2325, they could use Machine A to completely immerse themselves in the event, as if they were there.  But if all they can do is witness, not impact that event, this does not constitute time travel.  They would need something else - let's call it Media B - that they could reprogram.  Media B would have to have been already present at the event in 2325 for it to be reprogrammable in 2925 and have an impact in 2325.  

Media B would have to be something highly unstable.  Something that does not change its state in a linear repeated fashion.  Media B is what needs to be invented to realize time travel.  But here's the thing.  What if, in the year 2925, it is already invented? What if we are surrounded by Media B, but it's impact on our lives is completely indirect, independent of our awareness of it?  This seems unlikely.  For Media B to have the most impact it would mediate through our awareness, since human consciousness produces more change in the world and more rapid change than anything else.  Human desire is a highly effective medium for changing reality.  

So then, a different question, what if we are surrounded by this unstable Media B, but not at all clued in or aware of it?  

This starts to get non-rational very quickly, obviously, but that feels like part of what we may need to get more comfortable with these days.  If the artificial intelligence community is right, our current computer programming may be like cuneiform tablets compared to what computing will be by the end of this century.  Molecular computers, atomic computers etc.  It is hard to imagine a Media B wouldn't emerge in a couple generations.

As an aside, time travel seems increasingly more feasible than undoing white supremacy in the United States.