Log in

No account? Create an account
shpalman [userpic]

Comment on "Journeys in the country of the blind..."

4th July 2007 (09:49)

BPSDBeCAM say that they “aim to post within 7 days all E-letters that make a valid contribution to the topic;” well, it's been a week so I'm going to post the eLetter I submitted here.

Comment on “Journeys in The Country of The Blind: Entanglement Theory and The Effects of Blinding on Trials of Homeopathy and Homeopathic Provings” [eCAM 4 (1) 7-16 (2007)].

Submitted 26th June 2007, and again 3rd August 2007. Published online 6th November 2007

Lionel R. Milgrom is correct that his recent article [1] contains the word “metaphor” many times. However, it also contains the terms “model” and “analogy” and these words have much stronger meanings. In the abstract he writes of “a kind of quantum superposition between the remedy and placebo” - are we to take this as a metaphor, or to assume that the author means that there really is a quantum superposition?

Assuming an interpretation where this is meant metaphorically, the explanation is confusing, unhelpful and misleading to those readers who are not specialists in physics. Also, without specifying exactly what is intended literally and what is intended as metaphor it is not possible to evaluate the information content of the hypothesis. How much of a physicist's understanding of quantum mechanical phenomena could be transferred to homeopathic phenomena?

However, assuming a stronger interpretation, the author is quite definitely wrong. Coherence over such large macroscopic states containing so many interacting particles persists only for tiny fractions of a second [2,3]. The author mentions superfluid and superconducting states but these exist at very low temperatures, below about -271°C for superfluid helium [4] and -233°C for superconducting magnesium diboride. These states are characterized by an “energy gap,” meaning that the system is unable to dissipate any energy smaller than a certain critical amount, so at low temperatures interactions are actually suppressed. In a conventional superconductor the coherence length (over which two electrons form a so-called “Cooper pair”) is only about 1 micrometre [5]. The paper [6] which the author cites in his eLetter in response to Gates seems to mainly discuss the role of Einstein-Podolsky-Rosen-type thought experiments in interpretations of quantum mechanics [7,8,9]. This does not seem to be relevant to his statement that “the phenomenon of quantum entanglement is actually not limited by the size of the system being considered.” Entanglement is currently demonstrated in systems of just a few particles - for example, Vandersypen et. al. [10] managed to demonstrate a decoherence-limited quantum computation using seven nuclear spins, which are relatively robust. So the time and length scales over which quantum mechanical states exist at room temperature are much shorter than those which relate to human experience, especially considering the huge numbers of interacting particles in a human being (or a homeopathic preparation, for that matter).

There is a third possibility: that “a kind of quantum superposition” refers not to a kind of superposition as understood within quantum theory, but to a superposition within “a kind of” quantum theory, namely the “Weak Quantum Theory” [11] which the author cites. This paper, which contains at least one fundamental error by referring to photons as spin-1/2 particles (they are spin-1), seems to be motivated by a desire to generalize complementarity and/or entanglement to such concepts as the “relationship between conscious and unconcious processes” or “between mind and matter” (this latter obviously being predicated on Cartesian dualism [12]). There is absolutely no justification given for the applicability of Weak Quantum Theory to such things [13].

The author's main point is that a blinded randomized trial is “analogous” to the double-slit experiment, in which knowledge of which slit a particle went through destroys the interference pattern [14,15]. While this analogy should probably not be taken very seriously for the reasons give above, in the author's formalism there appears to be the misconception that when a wavefunction collapses, it becomes zero. This is not generally the case: it becomes the eigenstate which corresponds to the eigenvalue of the operator which has been measured and led to the collapse. In fact the “collapse of the wavefunction” is a simplification of how classical reality emerges via interactions between simple quantum mechanical systems and (quantum mechanical) measurement apparatus [16,17].

As for the author's statement that, “all truth, even scientific truth, is relative not absolute,” he is confusing the truth with our knowledge of it, and in doing so he is asserting an absolute truth [18]. Recent results which go against hidden variable theory [8] may demonstrate that the underlying reality is quantum mechanical and counterintuitive, but there is still an underlying reality.

Finally, the author writes energy / time for the dimensions of Planck's constant, which are energy × time [19].

web stats


Posted by: shpalman (shpalman)
Posted at: 22nd September 2007 08:25 (UTC)

See also Apathy Sketchpad.

Posted by: shpalman (shpalman)
Posted at: 6th November 2007 10:17 (UTC)

I've just received an email from the Commissioning Editor at eCAM which said that there “was a system error that prevented from letters to come through to me. I have checked your eletter, and this will be published shortly.” Sure enough, it's there: http://ecam.oxfordjournals.org/cgi/eletters/4/1/7#92.

Other contributions from Simon J. Baker and Austin C. Elliot have also appeared, and there is a reply from Lionel Milgrom which from its title seems to invoke Godwin's Law. But we'll see...

Posted by: shpalman (shpalman)
Posted at: 7th November 2007 21:57 (UTC)

Both Barrels

3 Read Comments