Homeopathy and the memory of water: memory or invention?

Carrying on with tidying up my comments on “The Memory of Water” issue of the journal Homeopathy I come to a paper that I actually looked forward to reading.  Vybíral and Voráček presented some interesting looking measurements on what they termed the autothixotropy of water.

Why was I interested?  A long time ago (final year undergraduate project no less!) I found thixotropic behaviour and hysteresis in samples of used engine oils taken from trains for condition monitoring purposes.  So I was interested to hear of this sort of rheological behaviour in water.

On reading the paper, I had two main concerns.  First, that the authors both assumed and asserted the existence of water “clusters” in the absence of evidence [The “sceptical” paper in the issue by José Teixeira actually says that: “There are no water clusters in pure liquid water, but only density fluctuations.”] Second, that they did not systematically explore what was actually causing this interesting effect.

Quite what water getting more or less “sticky” with time and shear has to do with homeopathy or a memory mechanism, I don’t know.  Anyway, here is the letter I submitted to Homeopathy.

Vybíral, B. and Voráček, P. “Long term structural effects in water: autothixotropy of water and its hysteresis” Homeopathy, Volume 96, Issue 3, July 2007, Pages 183-188.

Going Beyond the Evidence

Vybíral and Voráček [1] present some interesting, though incomplete, data on the bulk rheology of weak aqueous solutions of unidentified ions (referred to as “water” in the title of their paper).  However, they draw conclusions that go far beyond what their data can support.

Most strikingly, the paper is replete with references to “clusters” but contains no evidence to support the existence of any particular structure.  The authors own data are measurements of specific bulk rheological properties of the fluid samples.  Therefore reference to “clusters” in this paper represents both speculation and assumption on the part of the authors.

One consequence of this is that they see conflict where none exists.  For example, they state: “Currently two diametrically sets different of results supported by serious observations exist concerning the duration of structures in liquid water. According to one, molecular clusters in water have a duration of less than one hundred femtoseconds. According to ours, clusters grow to webs on a time scale of days” Here they show confusion about two particular issues.  First they have no observations on the durations of any structures; just a time (and shear history) dependent change in viscosity.  Second, Cowan et al. [2] comments on hydrogen bonded structures in “pure” water rather than effects due to low concentrations of ions, as examined in this paper.

This confusion leads to a failure to compare like with like: “Moral:  If two different observations seem to be mutually incompatible within the frame of an established theory, the most probable explanation is not that one of the observations is wrong, but that the theory is wrong or at least incomplete, and that the observations merely discovered that it was not self-consistent.”  This is just muddled thinking; there is no incompatibility between their observations and those of Cowan et al. [2].  The authors demonstrate that their observations are the result of low concentrations of ions present in the water.  Whereas Cowan et al. [2] address the highly transient nature of hydrogen bonded structures in “pure” water.

Given the determining role of aqueous ions in their observations it is surprising that the obvious questions are not addressed, such as: What species of ions are responsible for this effect?  How does this effect vary with ionic concentration? Where are these ions coming from (silica leaching from glassware or the decomposition of organic impurities in the water, for example)?

 Finally, what emerges from the actual evidence contained in this paper is of little discernable relevance to either homeopathy or the idea of water memory.  The effect measured depends on an actual concentration of ions and disappears when they do.  The autothixotropy appears over time with no external input.  Therefore, if it is possible to regard the time (and shear history) dependent change in viscosity they observed as “information” (quite a stretch!), the “information” content of the “water” is increasing with time in the absence of any input.  This is not a memory mechanism, but rather one of invention.

1.         Vybíral, B. and Voráček, P. “Long term structural effects in water: autothixotropy of water and its hysteresis” Homeopathy, Volume 96, Issue 3, July 2007, Pages 183-188.

2.         M.L. Cowan et al., “Ultrafast memory loss and energy redistribution in the hydrogen bond network of liquid H₂O”, Nature 434 (2005), pp. 199-200.

[note: some interesting observations are made about this paper here during a review of the complete “Memory of Water” issue of Homeopathy.]