Conciousness?

Originally posted by Mentat
and that is that the mathematics of Quantum Mechanics work to describe the behavior of a particle very accurately, and can do so without the intoduction of conscious observation. The addition of the idea that consciousness is necessary is for the purpose of conceptualization and comprehension; and may indeed turn out to be true, but is not necessary for the mathematics to work, and is therefore (in my opinion) an unnecessary add-on that defies most of the things we know about consciousness and the brain.

Originally posted by Canute

I agree about keeping an open mind. My questions were intended to suggest that not everyone here was doing that. As Fliption said, there are some over-bold claims being made. As far as I'm aware the details of relationship between wave-collapse and conscious observation remain a mystery, or at least a matter of debate.

http://www.swcp.com/~hswift/swc/Summ...oswami9901.htm

The interpretational difficulties of quantum mechanics can be solved with the hypothesis (von Neumann, 1955; Wigner, 1962) that consciousness collapses the quantum wave function. The paradoxes raised against this hypothesis have now all been satisfactorily solved (Bass, 1971; Blood, 1993; Goswami, 1989, 1993; Stapp, 1993). There is, however, one question that continues to be raised: Is consciousness absolutely necessary for interpreting quantum mechanics? Can we find other alternatives to collapse and consciousness as the collapser?

Some of these alternatives propose to modify quantum mechanics in a major way (for example, nonlinear theories); others are not philosophically satisfactory (for example, decoherence theories); still others invoke other questionable physical theories in order to make sense of quantum mechanics (Cramers, 19; Penrose, 1994). But there are two theories, one due to David Bohm (19), and the other called the many worlds theory (Everett, 1957), that still attract a lot of adherents.

In this short paper, we will argue that Bohm's theory is better interpreted with collapse of the wave function (and therefore, consciousness brought into the arena). As for the many worlds theory, even the latest versions of this theory requires special treatment of the conscious observer in order to make sense, and is thus a dualist theory (readers can verify this following the same general argument as Squires (1987)). Some final comments are also made about the implication of this reinterpretation for Bohm's philosophy of implicate and explicate order.

The Reinterpretation of Bohm's Causal Interpretation

Bohm's basic idea is to represent the situation of quantum mechanics with a wave piloting a particle, an idea he took from de Broglie (19). However, whereas de Broglie envisioned quantum objects as a physical wave piloting a physical particle, Bohm's waves are not physical waves; instead, they satisfy the Schroedinger equation. In other words, they are wave of possibility given by the quantum wave function. By writing the wave function as a product of two quantities -- the amplitude (whose square gives us the probability of finding the object in a given region of space) and the phase, Bohm does recover Newton's equation for a particle with coordinate x (and velocity v) evolving in a trajectory. The trajectory then is claimed to represent the real world of Newtonian vintage. The wave guides the trajectory through the so-called quantum potential in addition to whatever other force-field the object is under. This quantum potential is non-local and the effect of it continues even in empty space, so, for example, Newton's first law that objects travel in straight lines in the absence of any external forces no longer applies.

In the case of the double-slit experiment, for example, Bohm's particle equation can show us curved trajectories of how a particle may be able to go through one slit and still arrive at classically forbidden places on a fluorescent plate. How does the particle know that the other slit is open and veer itself to the quantum mechanically allowed places? Through the nonlocal influence of the quantum potential, which acts as a source of "active information."

Because the particle equation has been derived from the Schroedinger equation with only a little bit of redefinition of momentum (so that both momentum and position of the particle are simultaneously definable), it is assumed that Bohm's theory is equivalent to quantum mechanics (although there are some subtle differences). Bohm and his collaborators think that this is a causal interpretation of quantum mechanics because a classical trajectory has been calculated. But this thinking is fallacious.

The classical equation in Bohm's theory is not, strictly speaking, a space-time equation because the quantum potential depends on the wave function, which has no space-time existence until it is collapsed. Thus the causal discontinuity of quantum mechanics still remains because without wave function collapse, without knowing where the particle ends up, Bohm's method cannot be applied to calculate the particle trajectory.

Through sheer sophistry, Bohm and his collaborators avoid dealing with the fundamental problem of quantum measurement: why only one of the possibilities become actual in a measurement while all others do not. As Henry Stapp (1989) has already pointed out, the measurement problem is "bypassed" by assuming that the quantum potential forces the particle into one channel, although the other channels of the wave function remain empty. Stapp also points out that only the probability is testable even in Bohm's theory (as in quantum mechanics), not the quantum potential. In Stapp's opinion, a theory such as Bohm's that does not add anything tangible to quantum mechanics, but only adds extra elements on the basis of classical intuition, is not worth much investigation.

However, over the years, Bohm's theory has enjoyed a certain popularity and should not be dismissed off hand. Like Stapp, we believe that the measurement problem is not solved by Bohm's interpretation of his mathematics, but suppose we interpret Bohm's equations without any classical prejudice. What then?

Suppose we agree, as logic dictates, that Bohm's calculations are pertinent only in the aftermath of the wave function collapse, only when we know where the particle has ended up in a given measurement. Bohm's method then enables us to calculate the entire trajectory leading to the point of collapse. Thus the collapse can be seen to entail not only the possibility wave collapsing to a particle at the point of collapse, but the collapse of the entire trajectory going backwards in time.

Notice that, in this view, discontinuity of collapse remains: out of all the quantum possibilities a unique actuality is discontinuously chosen (by our observation and in our experience). But now we can go back in time and reconstruct the pathway of events in space-time leading to the event of collapse. We cannot relive these past events in the present moment, but there may be (fossil) remnants of these events now that may enable us to verify the validity of such a reconstruction.

Bohm has always emphasized how beautiful his theory is for understanding and appreciating quantum nonlocality as the action of the quantum potential. Yet Stapp's criticism cannot be denied: the quantum potential is not an observable. But under the action of the quantum potential, the calculated trajectories of Bohm's theory have unusual characteristics. Could these unusual characteristics be observable?

One such unusual characteristic is faster-than-light propagation. In the phenomenon of quantum tunneling, the time taken by a quantum object while going through the tunnel can be measured, and such measurements are now revealing a compelling case of faster-than-light propagation (Chiao). This, in our opinion, proves the usefulness of Bohm's theory.

Is such faster-than-light propagation against the theory of relativity? Hardly. We still cannot directly observe the object in its faster-than-light condition, any attempt to observe will destroy the tunnel. Speed-of-light limit applies to trajectories that are directly observable; the trajectories of objects in tunneling a' la Bohm are unobservable, so no challenge of relativity theory is necessary.

Implicate and Explicate Order

In his philosophical writings, Bohm also also leaves us with the impression that reality comes to us via two orders, one implicate or implicit or hidden that guides the behavior of what is explicate or explicit, the order that we see, the order that is causal and objective. With a reinterpretation of Bohm's work, his philosophy of implicate and explicate orders also needs to be modified.

The implicate order is easily seen as the transcendent order of quantum potential where ontologically, the quantum wave functions or possibility waves reside. The explicate order, however, is neither causal nor objective. It is not causal because there is no way to calculate the trajectories of objects in it a priori and thus there is no reason to assume that they exist a priori, before the discontinuous wave function collapse. It is not objective, because the result of wave function collapse happens in our experience; collapse cannot be eliminated and neither can the observer from our description of reality. The collapse of the present event, however, brings about the collapse of an entire pathway of events leading to the present moment going backwards in time. These past "events" cannot be lived now, but certain remnants or memories of these events elicited now can reveal their implicit existence.

In the human dimension, the idealist interpretation is being used to construct a new science within consciousness that can treat not only the material world, but also our internal mental world, for example, a theory of creativity (Goswami, 1998). A creative experience is sudden and discontinuous, a quantum leap, according to this theory. Although many creative people describe their creative act this way, a considerable amount of controversy exists showing a lot of disagreement with this position. Bohm's ideas can resolve the controversy. Although discontinuity dominates the creative experience, after the event, if there is enough memory from the ex-post-facto collapsed past, then one can reinterpret one's experience as a continuous one, especially if one's prejudices are disposed that way.

In conclusion, with this straightforward interpretation of Bohm's work, we have demonstrated that collapse of the wave function and consciousness as the causal agent for collapse remains basic in any interpretation of quantum mechanics and any understanding of quantum measurement.

Originally posted by Canute
Onycho.

Thanks for that. It's funny how science cannot get rid of consciousness. It must be damn annoying. [b(]

Originally posted by Mentat

People,
This is getting ridiculous. No offense, onycho, but nothing that's been posted here has shown that consciousness is necessary for quantum weirdness. The introduction of consciousness as a key player in QM is for the purpose of conceptulatization and comprehension, it is not necessary for the mathematics or for the physics.

Trying to discover quantum theories of consciousness is also a dead-end, AFAIC, since if consciousness were a quantum phenomenon, then thought would have to exist as discreet entities...and this cannot be the case, as per the homunculun problem of philosophies of the mind.

In short, the introduction of consciousness into quantum mechanics is just a desperate attempt to conceive of it, when (in my opinion) conception is almost completely irrelevant to use, and is thus not a worthy goal.

The more authentic illustration of the physical world became possible only when the ego-centric concept of objective and universal human perception was abandoned.

Originally posted by selfAdjoint
Not many physicists ever bought Wigner's vision, but mystics jumped on it merrily. Physics has been digging out ever since. The modern theories of decoherence and consistent histories represent the professional physicists' attempt to deal with interpretation questions in a non-woozy manner.

So you can expect to meet resistance whenever you attempt to introduce the "consciousness is needed to collapse the wave function" meme on a serious scientific board.

After impressive proofs of a string of theorems establishing the equivalence of measurement data and microscopic properties, the equivalence of the respective probabilities, and the outcome of repeated measurements of the same system with respect to the same observable, Omnès (1994, p. 338) derives the general form for state vector reduction. Ironically, in light of the comment sometimes made that decoherence offers merely a "calculational tool" (Kiefer 1991, p. 379), this rule for state vector reduction emphatically does not describe a real physical process; it is, instead, merely a computational convenience for predicting the outcomes of measurements. State vector reduction, on the other hand, may be dispensed with altogether as an actual physical process. Instead, the wavefunctions of measuring apparatuses and the like could, in principle, be followed in minute detail, nonetheless turning up -- on account of decoherence in the measuring apparatus -- the very same results. With its stipulation that macroscopic objects behave classically (a stipulation, incidentally, which is explicitly inconsistent), the Copenhagen interpretation guarantees the same calculational result, but on the present view both the quasi-classical macroscopic behaviour and the mathematical rule of state vector reduction can instead be derived.

Whether decoherence answers all the philosophical questions we'd like answered, and in particular whether it overcomes John Bell's (1990) criticism of interpretations of quantum mechanics which start and end by pointing out that quantum theory gives the right answers -- interpretations which he derides as 'For All Practical Purposes'.

Originally posted by onycho
Mentat, with all due respect, you have posted nothing that proves quantum weirdness must only be interpreted by currently known mathematics or physics.

Originally posted by onycho
Mentat, with all due respect, you have posted nothing that proves quantum weirdness must only be interpreted by currently known mathematics or physics.

Respectfully quantum theories of consciousness is not a dead-end (AFAIC's canon) as consciousness reality would necessarily have to be left unexplained.

Your above opinion statement is a dichotomy on its face. For you to conceive that consciousness and quantum mechanics are irreconcilable is truly a desperate attempt to hold long held theories sacrosanct.

The more authentic illustration of the physical world became possible only when the ego-centric concept of objective and universal human perception was abandoned.

Originally posted by onycho
As you say, "modern theories of decoherence may attempt to deal with
with interpretation questions in a non-woozy manner" but the important point for the measurement problem is that it is decoherence in the measuring apparatus which transfers the quantum property of a microscopic system into something real and distinguishable -- and observationally meaningful -- in the macroscopic world.



I fear that modern physics may believe that they are digging their way out but in my humble opinion may just be digging a deeper hole.

Originally posted by selfAdjoint
Second, it's hilarious that these deep thinkers think they are critiquing quantum mechanics when it just goes ahead discovering new hings about the universe while they remain stuck like little kids trying to assemble a kit that has both mysticism and quantum in it, and they just can't get them to fit together.[/B]

Originally posted by Canute
Yeah, it's funny how many scientists and philsophers are prone to it. Perhaps it's because the mechanisms of quantum mechanics and the nature of matter and consciousness remain a bit of a mystery.