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Monday, 29 June 2015

Objectivity

The way I've come to think about this is that conscious experience is constantly bifurcating, one half migrating towards a subjective pole and the other half migrating towards an objective pole. Some aspects are even represented at both poles, allowing William James to claim that their subjective and objective aspects are "the same experience given twice over" (in his essay Does Consciousness Exist?). I would also follow a Wittgensteinian line and say we should be suspicious about our inclination to reify notions as a result of the way we use language, and I'm thinking particularly of the ideas of 'objectivity', 'subjectivity', and 'knowledge' here. Regarding this bifurcation and migration process (here I'm giving a nod in the direction of Whitehead) -- is it "desirable"? It is some of the products of this process that behave in terms of desires and aversions, so from this wider perspective the question seems misplaced -- that kind of thinking pertains to things that are embedded within this World of Pure Experience (James again).

The "Measurement Problem".

When we observe an object for a while, then stop observing, and then take up observation again, we don't know what has happened to the object between those two periods of observation, so its state at the start of the second period of observation is not deducible entirely from ts state at the end of the first period of observation. There is an epistemological uncertainty involved.

When a quantum object interacts with a piece of apparatus and its state is recorded by that apparatus, we can determine what the state of the object was at the time of interaction. If the object is allowed to continue without interaction with any other object whatsoever for some finite duration, then there is no record anywhere of what happened to the object between that interaction and its subsequent interaction, so its state on subsequent interaction is not deducible entirely from its state on the prior interaction. However, it seems to be the case that this is an ontological uncertainty rather than an epistemological uncertainty.

I've come to regard this "superposition of states" for quantum objects as more of a superposition of histories. In the case of a quantum object passing through a single slit and meeting a detector, the superposition of histories is constrained to a single slit, so the detector only sees particle-like behaviour. In the case of a quantum object encountering double slits and meeting a detector, the superposition of histories has to take into account both slits, so the detector sees wave-like behaviour.

The two-slit scenario is a highly constrained case of the quantum object "going everywhere" (i.e. a case where most of "everywhere" has been narrowed down to two slits), this notion of "going everywhere" being what I take to be metaphor for "having all possible histories". It may even be the case that a non-interacting quantum system can be considered to be constituted by all of its "possible histories". This interpretation would also be consistent with the "delayed choice" and the "quantum eraser" variations of the two-slit experiment.

Note that human consciousness in the form of a human "observer" is not implicated in these scenarios, but the mystery of ontological uncertainty remains.