Let me warn you right now: this is going to be VERY thick. Other than Aaron
Kulick and Erik
Vieira, I don't know anyone who I expect to read right though this and understand it on the first pass. Most readers will need several readings, and probably a few hours free time on
Wikipedia to get the gist.
Now then: I have finished
ANATHEM, discussed briefly infra, and was a bit disappointed that Neal Stephenson didn't continue his exposition of theoretical human consciousness to what I thought would be the logical conclusion. To be honest, this post is only going to make a whole lot of sense to people who have both read and understood most or all of
ANATHEM, which means that they have (or have gained) at least a passing understanding of quantum theory, specifically relating to the Many Worlds Interpretation (
MWI), and also to q-bit processors and the rational decision-making process of the human mind.
But for people who can't get through the book or who need a quick refresher,
ANATHEM as a whole is about the intersection of worlds in the
MWI, both in terms of physical movement of persons between such worlds, and also the flow of information between those worlds.
MWI states that every possible world that can exist DOES, and that the collapse of any
probabilistic wave-form into a definite state (whether such collapse is an atom changing it's rotation - or decaying altogether - or you choosing to have chicken instead of steak for dinner) reflects a tacit "branching" of universes, both of which are real and complete. There exists a very nearby parallel cosmos, which exists independent of ours, where the only difference between that universe and ours is the direction of rotation of a single atom in the wood of the desk in front of you. A separate, complete, and independent cosmos exists where each
individual atom (or combination of atoms) spins differently. Rationally
speaking, those
cosmi are located very near to ours, and are visibly identical to ours (since the only
difference is the direction of rotation of a few atoms), but each of the
cosmi/universes DO exist under
MWI, BECAUSE THEY CAN. Such universes are casual domains with each other: each are separate and theoretically independent, but each have limited interaction with each other (as demonstrated by early-model Q-bit processors, where each bit is a one AND a zero, and as discussed by Stephenson under the moniker of the
HTW, rays of which permeate all universes). Among the bundle of these universes developing more or less parallel, worlds near ours are more or less indistinguishable, but as you move to
steadily more distant universes, more tangible changes appear. Rather than the only difference being the spin of an atom, there are parallel universes where you had something different for dinner last night. Or where you were five minutes late getting home because you chose not to run a light that was turning yellow. In that universe, your lateness in turn resulted in you getting home five minutes after that stray cat walked through your yard, so you didn't scratch it's ears, so you didn't give it milk, and so it and it didn't keep coming back; thus in one universe you have a cat, and in another you don't, based substantially on - among other things - whether or not you ran that yellow light.
But each choice or
seemingly random development (i.e.: each collapse of a probability waveform into a determinate state) reflects a slightly different universe, each of which universe
exists whole and complete, and mostly separate from ours (but for minor interaction, again as casual domains
exemplified by such things as q-bit processors). As differences between
universes become more substantial, those universes hypothetically have less and less similarity with our own, with less and less intersection: the domain containing the two universes becomes increasingly casual, until you finally reach universes relatively unrelated to our own, such as, for example, one where you're not really reading this, and where you never lived, because you died of pneumonia as an infant. Or where you were never even born, because you mother died of pneumonia as an infant.
Again, under
MWI, every universe that can exist, DOES, AND ALL AT THE SAME TIME. The equation becomes really impressive when you broaden your mind to consider that in addition to all the infinite universes that can exist under the laws of physics we know, there potentially exists distant universes where the laws of physics are slightly different from ours. For example, universes which have even slightly different masses at the time of their respective Big Bangs (which is possible under string theory, based on the possible differences in the vibrations of the many various strings of the universe at the time of the event). Such universes would have different total masses comprising the difference universes, which results in slightly different gravitational constants between those universes, which in turn hypothetically results in such things as light traveling at different speeds in each of those universes. Having a different figure for the speed of light has effects on the total physics of the universe. (Trust me on that.)
MWI allows for universes where the laws of physics are different, or at least based on different base constants. Then consider universes where (again, as a result of different competing string theory influences) the Big Bang for that universe happened a few
milliseconds (or
millennia) before or after the Big Bang in our universe, but which universes have developed along otherwise identical lines. A completely identical universe, except where the timeline has not yet developed any life at all, or where any life has already evolved into pure energy.
In sort, under
MWI, everything that is, was, will be, OR MIGHT BE all exists at the same time, running in universes that are more or less parallel, and that are more or less nearby to ours (including limited exchanges of information between casual domains), based on how similar such universes are to ours. As loopy as all this sounds, and as unwieldy a theory it is, as it seems considering that every
infinitesimal decision or development reflects an entire new universe, the alternatives to
MWI theory (which theories also account for certain particulars of quantum behavior) make even less sense than
MWI.
ANATHEM discusses all this, including - as above - the possible flow of information and/or matter between those universes, as interaction of casual domains.
With me so far?
In addition to expounding and creating fiction based on
MWI,
ANATHEM also discusses the nature of human consciousness, particularly
vis-a-
vis why people worry about some things - for example, a close friend moving away - but don't worry about others - such as our cities being destroyed by pink dragons flying the skies farting nerve gas. The theory offered by Stephenson in
ANATHEM is that the human mind is essentially a powerful Q-bit processor (wiki it), which has a hard-wired quantum logic map of the local cosmos as we understand it. When presented with a hypothetical situation ("Might I be killed by nerve-gas farting pink dragons?") the mind compares that possible situation with the quantum map, and more or less instantaneously determines if there is any possible way that the wave-forms (possible decisions and developments) on the logic map we have of our universe might possibly collapse in such a way that dragons might exist/appear and start killing razing cities. Since the realities of our universe, as reflected in the quantum logic map in our minds, are not likely to have that result, we don't worry about them. Such a result is impossible, or at least so improbable as to be unworthy of consideration, much less worry.
On the other hand, when we ask ourselves "Is [this person] going to move to a place where I might never see them again?" our mind determines that the wave-forms on the logic map (and the wave-forms of the universe, by extension) could easily collapse into a pattern where that result becomes reality. We recognize that it is possible, so we worry about friends moving away, with the degree of worry based on all of the factors that might lead to them moving away. When there are more factors indicating someone might move away, our minds (calculating as q-bit processors all possible results that do or might come to pass based on factors on the logic map of the universe we carry) tell us that it is that more likely that the probability wave-form will collapse into a reality where the person DOES, in fact, move away.
In effect, our minds are programmed with a model of reality (and of possible realities). By reference to that model, our mind can determine what we need to worry about (things that might actually come to pass in this universe), and things that we don't need to worry about (things are are impossible or improbable in this universe). In effect, our minds consider all possible developments that might come to pass based on relative constants intrinsic in the universe we occupy, and thereby determine what is and is not likely to come to pass, based on how each hypothetical development fits into our conception of the universe (or, alternately, what is impossible or improbable based on those same constants). In effect, the mind is a vastly powerful Q-bit processor, capable of
instantaneously processing vast numbers of variables to determine the probability of any given even coming to pass. (For the record, I'm fighting off a segue into
Hitchhiker's Guide to the Galaxy, and the implications of the improbability drive in light of the
MWI.)
Now, as I was reading
ANATHEM, I kept expecting the discourse on the
MWI and the discourse on human consciousness to converge. I expected to see the hypothesis that human consciousness and thought is simply the exchange of information between nearby universes, based on the idea of interaction of more or less casual domains. Does our consciousness subconsciously extend into nearby parallel universes (as casual domains), to see what's going on there?
For example: under Stephenson's explanation of human minds as powerful q-bit processors, every
calculation is of
astronomical complexity, based on a nearly infinite number of variables. Our mind needs to
crunch the numbers of the variables to determine the probability of any given result happening. Even a call as to whether we need to fear pink dragons nerve gassing us, which call has very clear results: we don't need to fear them - is an incredibly complex calculation, even when you have Q-bits to work with (since you need enough bits to encompass the equation).
But as Stephenson himself points out, maybe nature has already found an easier way. Under
MWI, every possible universe that can exist does, and nearby universes are - hypothetically at least - casual domains. Notwithstanding the plot of
ANATHEM, it seems likely that the nearest universes to ours are the ones almost identical to ours, with steadily more and more substantial changes as you move to more distant universes, until you reach a boundary (applicable to today's post in a way that will soon be clear) where those universes no longer contain a counterpart "us." Given the existence of such parallel worlds, and given that most of those nearby worlds include a counterpart of
ourselves (usually living a pretty
comparable life), isn't the answer to this amazing Q-bit calculation already there for quick reference? Does our mind really
need to perform an incredibly complex Q-bit calculation to assess pink dragons? Or can our minds simply perform a subconscious 'ping' of our counterparts in nearby/parallel
MWI universes, to the effect of "HEY! Anybody ever see a pink dragon farting nerve gas? No? Alright. I'm not going to worry about it, then."
Since universes near ours are generally pretty similar to our own, and since none of our counterparts in the nearest of those universes has ever seen a pink nerve-gas farting dragon, we can put it out of our mind. We reach a consensus
among ourselves in nearby universes, and thus comfortably put so unlikely an event out of our minds. Universes where such things as pink dragons can and/or do exist are different enough from our own that, even if there is a counterpart "us" in that universe, it is so far removed from our own universe that we hardly hear its response to the 'ping.' Although, incidentally, the fact that we can imagine pink dragons at all suggests that such things might exist: If not as leakage of information from distant (yet still casually related domains), where do such tacitly off-the-wall ideas come from? Science doesn't like the idea of ideas spontaneously forming in our heads from nothingness; on some levels, that sort of spontaneous creation seems to violate the laws of conservation of energy.
So, along these lines, I kept expecting Stephenson (or
Orolo, or
Jad, one of the
Thousanders) to offer the idea that our minds are simply in casual (
subconscious) contact with our counterparts in many "nearby"
MWI universes. Our decision making process doesn't need to crunch amazing numbers with Q-bits, it simply needs to ask our other selves, and look briefly at the Big Picture, to see if any given event is possible or probable. Our ideas, hopes, and fantasies are simply communications from more distant casual domains, bleeding over into our conscious minds in this one as ephemeral concepts (as compared to the realities that they ARE in their distant origin universes).
Now I confess that I really don't know enough about quantum mechanics to really offer this theory as a viable hypothesis for explaining human decision-making and consciousness. But I still think it's a pretty fucking cool idea.