----- Original Message -----
From: "Gordon Fitch" <gcf at panix.com>
> Even if so the problem I mentioned would remain -- the world
> is not mindless, therefore a description of the world must
> include mentation _as_such_ (that is, not as mere descriptions
> of mechanical behavior), and those mentations must include
> the subjective experiences of the observers.
>
> The gratuitous assumption of a mindless predecessor of the
> present world produces all sorts of difficulties, like the
> mind-body problem and the appearance of consciousness _ex_
> _nihilo_, which seem superfluous to me. Why bother? Unless
> you like that sort of thing, of course.
>
> -- Gordon
===================
Despite the unrivalled empirical success of quantum theory, the very suggestion that it may be literally true as a description of nature is still greeted with cynicism, incomprehension and even anger.
The particular implication of quantum theory that all the fuss is about is of course, as Lockwood puts it, "the simultaneous existence of distinct . experiences" (of a single person). For instance, as I write this, I am having the experience of drinking tea. Quantum theory implies that vast numbers of other experiences of mine, including the experience of drinking coffee at this moment, are also taking place. The reason why I do not have an experience of having all those experiences simultaneously is that the laws of quantum mechanics restrict the operation of our brains so as to confine, as Lockwood puts it, "the gaze of consciousness to a kind of 'tunnel vision' directed downwards in the experiential manifold. We cannot look 'sideways' through the manifold, any more than we can look 'upwards', into the future."
All experiences are presumably associated with measurements, and as Lockwood explains, measurements create quantum entanglement between the observer and the measured system. This means that in those parts of the "experiential manifold" where I was having the experience of drinking tea, I also had the experience of reporting that experience to you in the paragraph above. Likewise for coffee. Consequently, whenever I believe that I am perceiving something real - for instance, if I take it that there really is a cup of tea here on the table - quantum theory obliges me to believe the same of those other perceptions which it says that I am also having. In other words, the coffee, and virtually every other physical object that I am capable of perceiving and reporting to you, must be on the table too, though I cannot see them from here. Thus the "simultaneous existence of distinct experiences" is a special case of a general multiplicity in physical reality at large.
I have just said both that I cannot see the coffee, and that I am having the perception of seeing coffee. This is no contradiction, merely two different uses of the word 'I'. The problem here is that ordinary language implicitly makes the false assumption that our experiences (and observable events in general) have a single-valued history. To help resolve the ambiguities created by this assumption, Lockwood introduces the term Mind to denote the multiple entity that is having all the ("maximal") experiences that I am in reality having, and reserves the term mind for an entity that is having any one of those experiences. So I (the Mind) am both seeing tea and seeing coffee, and am simultaneously reporting both experiences, but I (the mind), who am writing "tea", am seeing only tea. Similarly, we call multi-valued physical reality as a whole the multiverse, to distinguish it from the universe of classical physics in which observables can take only one value at a time.
Quantum entanglement makes my experience of drinking tea go with my experience of seeing and reporting tea, and therefore presumably also with the presence of actual tea, but not with my seeing or reporting coffee, nor with the presence of actual coffee. Both the tea and the coffee, and many other drinks, together with all the associated experiences, are equally present in reality. But quantum entanglement connects them in 'layers' - including a 'tea' layer and a 'coffee' layer. In each layer, the experiences correspond (roughly) with each other and with the physical objects that they are experiences of, but in any one layer there is no experience of any other layer (except indirectly, through interference phenomena). This is what motivates referring to each of these layers as a universe, and to layers of the multiverse collectively as parallel universes[2].
< http://www.qubit.org/people/david/Articles/CommentOnLockwood.html >
Ian