Water memory is a speculation that water is capable of retaining a memory of substances once dissolved in it, even after being diluted so much that the chance of even one molecule remaining in the quantity being used is minuscule.[1][2] Shaking the water at each stage of a serial dilution is claimed to be necessary for an effect to occur.[3] The concept was proposed by Jacques Benveniste to explain the purported therapeutic powers of homeopathic remedies, which are prepared by serially diluting aqueous solutions to such a high degree that even a single molecule of the original solute is highly unlikely to remain in each final preparation.
After the Nature controversy, Benveniste gained the public support of Brian Josephson,[13] a Nobel 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.[14] This was followed by two additional papers in 1999 [15] and another on remote-transmission in 2000 by which time it was claimed that it could also be sent over the internet.[16]
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, using “a randomized double-blind test”, of his claimed ability to transfer the characteristics of homeopathically diluted water over the Internet.[17] 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, which resulted in Benveniste writing “Fine to us.”[18] 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.[19]
An independent test of the 2000 remote-transmission experiment was carried out in the USA by a team funded by the US 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. Benveniste admitted to having noticed this himself, but instead of accepting that the positive effects were a result of experimenter effect, he offered a number of different explanations. The experiment is notable for the way it attempted to avoid the confrontational nature of the earlier Maddox test.[20]
Third-party attempts at replication of the Benveniste experiment have produced mixed results. Nature published a paper describing a number of follow-up experiments that failed to find a similar effect in 1993[21] and an independent study published in Experientia in 1992 showed no effect.[22] However, an international team led by Professor Madeleine Ennis of Queen’s University of Belfast claimed to have succeeded.[23] Randi then forwarded the $1 million challenge to the BBC Horizon program to prove the “water memory” theory following Ennis’ 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 the Horizon team failing to prove the memory of water.[24] For a piece on homeopathy, the ABC program 20/20 also attempted, unsuccessfully, to reproduce Ennis’s results.[25]
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.[6]