Water memory is the hypothesis that water has the ability to retain a “memory” of substances which have been dissolved in it, even at extreme levels of dilution such as those found in homeopathy. Since these dilutions typically result in not a single molecule of the original substance remaining in the solution, the hypothesis of water memory is required to make it even possible for homeopathic preparations to have any effect.
The water memory hypothesis runs counter to much of accepted physics and chemistry. While water molecules do have strong intermolecular forces (which explain the high surface tension of water), these forces are not strong enough to form structures which last more than a fraction of a nanosecond. No plausible mechanism for the water memory hypothesis has even been proposed.
The chief experimental evidence cited in favour of water memory comes from research conducted by French immunologist Jacques Benveniste in 1988. Benveniste diluted a solution of human antibodies to homeopathic limits, to the point that it was highly unlikely that there was any antibody left in solution. Yet the pure water still triggered the same allergic reaction as the original solution. Benveniste’s paper reporting these results was published in the prestigious scientific journal Nature, causing major controversy within the scientific community. The editors of Nature had insisted on adding an extremely unusual editorial disclaimer advising readers to suspend judgement on the results until they could be independently replicated.
As a result of the controversy, a team of investigators, including famed skeptic James Randi, observed a repeat of the experiment at Benveniste’s lab. The team observed that the experiment was not double-blinded, a standard protocol for minimizing bias in such experiments, where both the experimenter and the participants are blind to the treatment being administered. Once this was done, the results could not be replicated.
Although Benveniste later went on to claim the ability to transmit the homeopathic signals over phone lines and the internet, the vast majority of attempts to replicate Benveniste’s original results have given negative results.
In many ways, the story of water memory is an example of the scientific method working at its best: a lab produced a stunning result, with far-reaching implications for scientific theory; the results were published in a scientific journal; and many other scientists set to attempt to replicate and improve upon the original experiment. When further study failed to support the initial findings, the scientific community rejected the hypothesis and moved on. Unfortunately, the homeopathic community does not follow the scientific rulebook: 20 years after Benveniste’s claims were shown to be unreliable, homeopaths still cite his original research, with no mention of the many subsequent negative results.
Benveniste’s article: “Human Basophil Degranulation Triggered by Very Dilute Antiserum Against IgE” E. Dayenas; F. Beauvais, J. Amara , M. Oberbaum, B. Robinzon, A. Miadonna, A. Tedeschit, B. Pomeranz, P. Fortner, P. Belon, J. Sainte-Laudy, B. Poitevin and J. Benveniste, 1988.
Nature’s disclaimer: “When to Believe the Unbelievable” Maddox, John, 1988.