On the Nature of Existence

One thing that struck me while reading David Deutsche's Fabric was his explanation of time travel, particularly into the past. Deutsche claims that if it were possible, we'd be able to travel backward in time at a specific location. So if you built a time travelling machine in your garage today, in the future you'd be able to go physically to your garage and then use the 'in-place' machine to travel back in time at that same place. In your garage.

It's kind of hard to know what he means by "the same place" though. Relative to what exactly? The world is always moving so I'm pretty sure that if it's not relative to Earth, that's going to be a pretty shitty time machine. Unless, the reason that you must pin time travel to a specific location is that it gives you some continuity of "place" in space to revisit. (I strongly suspect that the physics of relativity might have something to say on this topic.)

This concern with the 'where' your time machine is puts the whole question of "time" and travel into a certain relief. What is now, exactly, and how does time relate to it? Well, I think one interesting way of thinking about the present is as a configuration of matter and energy.

Most physicists like to talk abut how time is just the movement of this configuration. The order and nature (energy or matter?) and location of that matter (let's ignore the energy part for a bit, since 'atoms' are a bit easier to wrap your head around).

In some ways, you can describe time through this movement of matter. In fact, the International Standards Organization does precisely this. They observe the movement of a particular configuration of matter, a particular isotope if I'm not mistaken, and keep track of its movements, or as they call them, oscillations. A certain number of oscillations corresponds to "time" of the "one second" variety. In order to know how long a second is, you merely count the oscillations up to known fixed, unmoving number.[1]

So what is time? Well, time is the movement, or reconfiguration, of matter. IN some senses, the world is this forever and perpetually updating state machine, every state progression of change is the 'passage of time'. For those of you who were rooting for us being inside a 'giant simulation' -- you're totally on the money. The simulation is the matter, the rules of the game are the Laws of Physics. A new phase begins, well, pretty much perpetually.

It's funny that quantum mechanics is the measurement of discrete quantities, because of continuous their movements are. So even if you can solve Zeno's paradox of the race by using quanta as discrete units, there's still a continual movement toward the finish line.

Correspondingly, time will end when matter, our time keeper, ceases to reconfigure.

This brings us to the real crux of what I wanted to get at today, some true ideas about the nature of our existence in such a reality. The truth about existence is that the only real thing is the current configuration of matter an energy. It, realness, is not a fixed thing. It is constantly changing. That, its movement, is time. That's existence. That's the Nature of the Simulation We All Inhabit.

So what is the past? Surely it happened. We can remember it. We lived through it.

Let me explain how this works. Reality is configurations of matter. Some of these configurations persist for longer 'periods of time' than others. Some of these configurations are displayed as statues in the park, or as a book on a library shelf. Other configurations that we have of the past are mass graves rotting in the sweltering deeps of Africa and piles of gold sitting in wire cages in a pit on Manhattan Island. Still other configurations are carried around with you, in your head, configured into the neural pathways and connections that have been formed through your seeing and bearing witness to the configurations of the past. What you see, waht you hear, what you feel -- these things all leave marks, traces, in the configuration of molecules in our brains.

The past leaves itself, literally, in you, as memories.

Where does that leave the future?

The future is the total set of all the configurations that that are physically possible to reach from here. There is no one future though -- they all have a possibility of existing, at least the ones that are possible, do. We only end up in one of them though. This is the problem of a lifetime, then, figuring which of possible paths through the configurations of matter will be the one we experience. It's completely unpredictable, or at least knowable. There's too much matter to keep track of. Because the sheer amount of matter is *immense*.

You can't experience all of the ways that matter moves because matter only has one configuration at a time. That configuration that we find ourselves in is reality.

But supposing that we did want to trace the future, to explore at least 'virtually' all of the possible, branching configurations (futures) that are reachable from this present (configuration).

Let's say that you could build a machine that could hold all of this state. One that was capable of tracking every atom in a simulation, and not just the atoms, but also their present location and momentum, where they'd be next. How much matter would it take to build such a system? It would need at least as much matter as the current system that it's attempting to model, plus more to enumerate each of the attributes of the potentiality for future configurations. Where would you store such a model? For a small, few atom or molecule, closed system you can definitely create such a replica, but anything larger than this quickly becomes actually really physically impossible. There is not enough matter in the world (or 'universe') to model itself completely. In fact, all of the matter in the world is currently busy -- doing just that.

There's two observations that I want to make from this. The first is that it, modeling reality, brings up an interesting way of looking at our current thing that we do with computers when we "store" information into them. We are configuring matter into a new configuration, one that "translates" into meaning for us. We feel that this comparison, this moving what used to have to be paper and rocks and plaster to make a scenery, we can now encode onto a flash drive.People often talk about informational compression algorithms in terms of photos or conversations, but there's another way of measuring compression. That's by measurement of the actual medium used to represent the state configuration.

You can kind of do it with matter, but it effectively requires you to create generalized rules that allow you to not precisely track the individual configuration of every piece of matter that is involved. As a terribly simplistic, paper and pen example, a red light can be depicted as a red dot, without having to know the trajectory and count of exactly how many photons are being emitted. It's a red dot.

I wonder sometimes what the total, material mass of state remembrance is right now. What the total count of "bits of matter" whose current configuration is being used to signify the past configuration of another reality, for all humans right now, presently. How much of this present reality, have we co-opted for another? If you were to add up all of the atoms that go into computer memory drives and human brain matter, what fraction of right now, the present, is consumed by wanting to be able to easily access a past configuration?

Looping back now to the time travel question that we started with, for me the biggest blocker to my understanding of how anyone proposes to "return" to the past is -- where does that leave the configuration of matter that is your present self? Further, how are you planning to "rewind" the configuration of every bit of matter to that particular point? This feels like the point where a physicist would point out that 'time is a construct' and there's nothing really keeping us from those past configurations. To which, I'd say is true except that the reality of us not being in that configuration, presently, seems to be inertia enough to keep us from moving back towards it. What's the plan, exactly, to "rewind" the configuration of every bit of matter to a particular, prior configuration? Matter doesn't have memory. It has movement, it has laws about that movement, it has new configurations and then sets of configurations that are possible from there. As discussed earlier, there's nowhere that we can store a copy of a prior state. It, matter, moves forward, in distinctive, mostly discoverable, paths.

Backwards is a completely ridiculous, human invented, conception of "what might be possible if the rules were different". Matter moves. That's all there is to it.

It moves everywhere, in every possible direction, but it only ends up in one -- Right Now.

What is Existence, really, then?

Existence is the ever-changing now.

Appendicitus:

A. I've been writing a bit on this blog about the multiverse, that there "is one". I think that all there is is configurations of matter that are possible, and the configuration of matter that is. These happen at the same time, because matter's movement is continuous. Thus, through one view we exist in a branch multiverse; in another there is only the actuality of the present configuration. We are living the heisenbergic uncertainty of knowing either existence or the possibility of it.

B. A small aside on state configuration and the sciences. Within the last few decades, a new-ish discipline has popped up, called "complex adaptive systems". It also exists in the science departments as 'chaos' theory mechanics. I've always been under the strong suspicion that such scholarship was on the brink of obsolescence, as our ability to observe and model finer and finer grained configurations of matter has improved. I believe I was wrong to write off such efforts as foolish. Now I believe it is impossible for us to precisely model complex systems, as the physical requirements for them are prohibitive. Chaos theory and its insights (whatever those might be, I'm admittedly completely ignorant to any of the most interesting capabilities of such scholarship. Fluid dynamics, being one such example of scholarship in the direction of "understand chaos mechanics")

[1] This is a lot more reliable than using the movement of the Earth about the Sun as the elliptical curve of the path the Earth takes changes, slightly every year. Similarly, the amount of time it takes for the Earth to do one full rotation (a day) is slowly slowing down. Precise, consistence measurements of time, based on astronomical movements is impossible, so we use the oscillations of an isotope. This divergence between the measurement of time and the experience of living in a world where night and day occur regularly but not precisely causes for problems in reconciling calendars. This is particularly pronounced for computers and machines that have a much finer grained sense of 'time' than we do.