|Claims||Under certain circumstances water can retain a "memory" of solute particles after arbitrarily large dilution.|
|Related scientific disciplines||Chemistry, Medicine|
|Original proponents||Jacques Benveniste|
|Subsequent proponents||Brian Josephson, Madeleine Ennis, Martin Chaplin, Luc Montagnier, various homeopaths|
Water memory is the claimed ability of water to retain a "memory" of substances previously dissolved in it to arbitrary dilution. No scientific evidence supports this claim. Shaking the water at each stage of a serial dilution is claimed to be necessary for an effect to occur. The concept was proposed by Jacques Benveniste to explain the purported therapeutic powers of homeopathic remedies, which are prepared by diluting solutions to such a high degree that not even a single molecule of the original substance remains in most final preparations. Benveniste sought to prove this basic tenet of homeopathy by conducting an experiment to be published "independently of homeopathic interests" in a major journal.
While some studies, including Benveniste's, have reported such an effect, double-blind replications of the experiments involved have failed to reproduce the result. The concept is not consistent with accepted scientific laws and is not accepted by the scientific community. Liquid water does not maintain ordered networks of molecules for longer than 50 one-millionths of one nanosecond.
The Nature controversy 
In the original study, French immunologist Jacques Benveniste's team at the French National Institute of Health and Medical Research (INSERM) diluted a solution of human antibodies to such a degree that there was virtually no possibility that a single molecule remained. Nonetheless, they reported, human basophils responded to the solutions just as though they had encountered the original antibody (part of the allergic reaction). The effect was reported only when the solution was shaken violently during dilution. Benveniste stated: "It's like agitating a car key in the river, going miles downstream, extracting a few drops of water, and then starting one's car with the water."  At the time, Benveniste offered no theoretical explanation for the effect.
Benveniste submitted the research to the prominent science journal Nature for publication. There was concern on the part of Nature's editorial oversight board that the material, if published, would lend credibility to homeopathic practitioners even if the effects were not replicable. There was equal concern that the research was simply wrong, given the changes that it would demand of the known laws of physics and chemistry. The editor of Nature, John Maddox, stated that, "Our minds were not so much closed as unready to change our whole view of how science is constructed." Rejecting the paper on any objective grounds was deemed unsupportable, as there were no methodological flaws apparent at the time.
In the end, a compromise was reached. The paper was published in Nature Vol. 333 on 30 June 1988, but it was accompanied with an editorial by Maddox that noted "There are good and particular reasons why prudent people should, for the time being, suspend judgment" and described some of the fundamental laws of chemistry and physics which it would violate, if shown to be true. Additionally, Maddox demanded that the experiments be re-run under the supervision of a hand-picked group of what became known as "ghostbusters", including Maddox, famed magician and paranormal researcher James Randi, and Walter W. Stewart, a physicist and freelance debunker at the U.S. National Institutes of Health.
In the first series of supervised experiments, the original experimental procedure was followed as it had been when the paper was first submitted for publication. The experiments were successful, matching the published data quite closely. However, Maddox noted that during the procedure the experimenters were aware of which test tubes originally contained the antibodies and which did not. A second experimental series was started with Maddox and his team in charge of the double-blinding; notebooks were photographed, the lab videotaped, and vials juggled and secretly coded. Randi went so far as to wrap the labels in newspaper, seal them in an envelope, and then stick them on the ceiling so Benveniste and his colleagues could not read them. No memory effect was observed in the blinded experiments.
Nature published a follow-up report in the next issue: "We conclude that there is no substantial basis for the claim that anti-IgE at high dilution (by factors as great as 10120) retains its biological effectiveness, and that the hypothesis that water can be imprinted with the memory of past solutes is as unnecessary as it is fanciful." Nevertheless, there was no suggestion of fraud; Maddox and his team initially speculated that someone in the lab "was playing a trick on Benveniste," but later concluded, "We believe the laboratory has fostered and then cherished a delusion about the interpretation of its data." Maddox also pointed out that two of Benveniste's researchers were being paid for by the French homeopathic company Boiron.
In a response letter published in the same issue of the journal, Benveniste lashed out at Maddox and complained about the "ordeal" he endured at the hands of the Nature team, comparing it to "Salem witchhunts or McCarthy-like prosecutions." In both the Nature response and a following Quirks and Quarks episode, Benveniste especially complained about Stewart, who he stated acted as if they were all frauds and treated them with disdain, complaining about his "typical know-it-all attitude". In his Nature letter, Benveniste also implied that Randi was attempting to hoodwink the experimental run by doing magic tricks, "distracting the technician in charge of its supervision!" He was more apologetic on Quirks and Quarks, re-phrasing his mention of Randi to imply that he had kept the team amused with his tricks and that his presence was generally welcomed. He also pointed out that although it was true two of his team-members were being paid for by a homeopathic company, the same company had paid for Maddox's team's hotel bill.
Maddox was unapologetic, stating "I'm sorry we didn't find something more interesting." On the same Quirks and Quarks show he dismissed Benveniste's complaints, stating that the possibility that the results would be unduly promoted by the homeopathy community demanded an immediate re-test. In failing, the tests demonstrated that the initial results were likely due to the experimenter effect. He also pointed out that the entire test procedure that Benveniste later complained about was one that had been agreed upon in advance by all parties. It was only when the test then failed that Benveniste disputed its appropriateness.
The debate continued in the letters section of Nature for several issues before being ended by the editorial board. It continued in the French press for some time and in September Benveniste appeared on British television to debate the events live with Randi and others. For all of the arguing over the retests, it has done nothing to stop what Maddox worried about; even in the light of their failure they are still used to claim that the experiments "prove" that homeopathy works. One of Benveniste's co-authors on the Nature paper, Francis Beauvais, later stated that while unblinded experimental trials usually yielded "correct" results (i.e. ultradiluted samples were biologically active, controls were not), "the results of blinded samples were almost always at random and did not fit the expected results: some 'controls' were active and some 'active' samples were without effect on the biological system."
Subsequent research 
In the cold fusion or polywater controversies many scientists started replications immediately, because the underlying theories didn't go directly against scientific fundamental principles and could be accommodated with a few tweaks to those principles. But Benveniste's experiment went directly against several principles, causing most researchers to outright reject the results as errors or fabrication, with only a few researchers willing to perform replications or experiments that could validate his hypotheses.
After the Nature controversy, Benveniste gained the public support of Brian Josephson, a Nobel laureate physicist with a reputation for openness to paranormal claims. Experiments continued along the same basic lines, culminating with a 1997 paper claiming the effect could be transmitted over phone lines. This was followed by two additional papers in 1999 and another on remote-transmission in 2000 by which time it was claimed that it could also be sent over the Internet.
Time magazine reported in 1999 that, in response to skepticism from physicist Robert Park, Josephson had challenged the American Physical Society (APS) to oversee a replication by Benveniste. This challenge was to be "a randomized double-blind test", of his claimed ability to transfer the characteristics of homeopathically diluted water over the Internet. The APS accepted the challenge and offered to cover the costs of the test. When he heard of this, Randi also offered to throw in the long-standing $1 million prize for any positive demonstration of the paranormal, to which Benveniste replied: "Fine to us." in his DigiBio NewsLetter. However, Randi later noted that Benveniste and Josephson did not follow up on their challenge, mocking their silence on the topic as if they were missing persons.
An independent test of the 2000 remote-transmission experiment was carried out in the USA by a team funded by the United States Department of Defense. Using the same experimental devices and setup as the Benveniste team, they failed to find any effect when running the experiment. Several "positive" results were noted, however, but only when a particular one of Benveniste's researchers was running the equipment. "We did not observe systematic influences such as pipetting differences, contamination, or violations in blinding or randomization that would explain these effects from the Benveniste investigator. However, our observations do not exclude these possibilities."
Benveniste admitted to having noticed this himself. "He stated that certain individuals consistently get digital effects and other individuals get no effects or block those effects."
Third-party attempts at replication of the Benveniste experiment have failed to produce positive results that could be independently replicated. In 1993, Nature published a paper describing a number of follow-up experiments that failed to find a similar effect, and an independent study published in Experientia in 1992 showed no effect. An international team led by Professor Madeleine Ennis of Queen's University of Belfast claimed in 1999 to have replicated the Benveniste results. Randi then forwarded the $1 million challenge to the BBC Horizon program to prove the "water memory" theory following Ennis's experimental procedure. In response, experiments were conducted with the Vice-President of the Royal Society, Professor John Enderby, overseeing the proceedings. The challenge ended with no memory effect observed by the Horizon team. For a piece on homeopathy, the ABC program 20/20 also attempted, unsuccessfully, to reproduce Ennis's results.
Research published in 2005 on hydrogen bond network dynamics in water showed that "liquid water essentially loses the memory of persistent correlations in its structure" within fifty millionths of a nanosecond.
See also 
- List of experimental errors and frauds in physics
- List of topics characterized as pseudoscience
- Pathological science
- Scientific misconduct
- Masaru Emoto
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- See Mole (unit) and Homeopathy for more detailed information on how we can calculate the original number of molecules.
- 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 (30 June 1988). "Human basophil degranulation triggered by very dilute antiserum against IgE" (PDF). Nature 333 (6176): 816–818. Bibcode:1988Natur.333..816D. doi:10.1038/333816a0. PMID 2455231. Retrieved 2007-06-05.
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- Robert Sheaffer (January / February 1998), "E-mailed Antigens and Iridium’s Iridescence", column "Psychic Vibrations", Skeptical Inquirer 22.1
- James Randi in interview for BBC Horizon: Homeopathy The Test, 26/11/2002
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- Homeopathy breakthrough
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- Philip Ball (2001), Life's matrix: a biography of water (illustrated, reprinted ed.), University of California Press, p. 328, ISBN 978-0-520-23008-8
- Brian Josephson, molecule memories, New Scientist letters, 1 November 1997
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- J. Benveniste; Thomas Y, Schiff M, Belkadi L, Jurgens P, Kahhak L (2000). "Activation of human neutrophils by electronically transmitted phorbol-myristate acetate". FASEB Journal 13 (1): 33–39. doi:10.1054/mehy.1999.0891. PMID 10790721.
- Leon Jaroff, Homeopathic E-Mail, Time Magazine, 17 May 1999]
- Jacques Benveniste and Didier Guillonnet, DigiBio - NewsLetter 1999.2, "Demonstration challenge, etc." section
- James Randi, Computer problems, a Nobel Laureate reneges, more magnetic shoes, the metric system, and ..., Commentary ,26 January 2001
- Jonas, Wayne B.; John A. Ives, Florence Rollwagen, Daniel W. Denman, Kenneth Hintz, Mitchell Hammer, Cindy Crawford, and Kurt Henry (January 2006). "Can specific biological signals be digitized?". FASEB Journal 20 (1): 23–28. doi:10.1096/fj.05-3815hyp. PMID 16394263. Retrieved 2007-06-05. — this paper includes an excellent references list.
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- Lionel Milgrom (2001-03-15). "Thanks for the memory. Experiments have backed what was once a scientific 'heresy', says Lionel Milgrom". The Guardian (Guardian Unlimited)
- "Homeopathy: The test. Transcript.". BBC Two. 2003-11-26, 9pm. Retrieved 2007-03-04.
- Stossel, John (2008). "Homeopathic Remedies - Can Water Really Remember?". 20/20 (ABC News). Retrieved 2008-01-22.