[escepticos] Insisten con la memoria del agua

["torabe" <torabe@...>]

Hola.

La fuente:
http://www.newscientist.com/news/news.jsp?id=ns99993817



Icy claim that water has memory



Claims do not come much more controversial than the idea that water might
retain a memory of substances once dissolved in it. The notion is central to
homeopathy, which treats patients with samples so dilute they are unlikely
to contain a single molecule of the active compound, but it is generally
ridiculed by scientists.

Holding such a heretical view famously cost one of France's top allergy
researchers, Jacques Benveniste, his funding, labs and reputation after his
findings were discredited in 1988.

Yet a paper is about to be published in the reputable journal Physica A
claiming to show that even though they should be identical, the structure of
hydrogen bonds in pure water is very different from that in homeopathic
dilutions of salt solutions. Could it be time to take the "memory" of water
seriously?

The paper's author, Swiss chemist Louis Rey, is using thermoluminescence to
study the structure of solids. The technique involves bathing a chilled
sample with radiation. When the sample is warmed up, the stored energy is
released as light in a pattern that reflects the atomic structure of the
sample.

Twin peaks


When Rey used the method on ice he saw two peaks of light, at temperatures
of around 120 K and 170 K. Rey wanted to test the idea, suggested by other
researchers, that the 170 K peak reflects the pattern of hydrogen bonds
within the ice. In his experiments he used heavy water (which contains the
heavy hydrogen isotope deuterium), because it has stronger hydrogen bonds
than normal water.


 Unexplained results
After studying pure samples, Rey looked at solutions of lithium chloride and
sodium chloride. Lithium chloride destroys hydrogen bonds, as does sodium
chloride, but to a lesser extent. Sure enough, the peak was smaller for a
solution of sodium chloride, and disappeared completely for a lithium
chloride solution.

Aware of homeopaths' claims that patterns of hydrogen bonds can survive
successive dilutions, Rey decided to test samples that had been diluted down
to a notional 10-30 grams per cubic centimetre - way beyond the point when
any ions of the original substance could remain. "We thought it would be of
interest to challenge the theory," he says.

Each dilution was made according to a strict protocol, and vigorously
stirred at each stage, as homeopaths do. When Rey compared the ultra-dilute
lithium and sodium chloride solutions with pure water that had been through
the same process, the difference in their thermoluminescence peaks compared
with pure water was still there.

"Much to our surprise, the thermoluminescence glows of the three systems
were substantially different," he says. He believes the result proves that
the networks of hydrogen bonds in the samples were different.




Phase transition



Martin Chaplin from London's South Bank University, an expert on water and
hydrogen bonding, is not so sure. "Rey's rationale for water memory seems
most unlikely," he says. "Most hydrogen bonding in liquid water rearranges
when it freezes."

He points out that the two thermoluminescence peaks Rey observed occur
around the temperatures where ice is known to undergo transitions between
different phases. He suggests that tiny amounts of impurities in the
samples, perhaps due to inefficient mixing, could be getting concentrated at
the boundaries between different phases in the ice and causing the changes
in thermoluminescence.

But thermoluminescence expert Raphael Visocekas from the Denis Diderot
University of Paris, who watched Rey carry out some of his experiments, says
he is convinced. "The experiments showed a very nice reproducibility," he
told New Scientist. "It is trustworthy physics." He see no reason why
patterns of hydrogen bonds in the liquid samples should not survive freezing
and affect the molecular arrangement of the ice.

After his own experience, Benveniste advises caution. "This is interesting
work, but Rey's experiments were not blinded and although he says the work
is reproducible, he doesn't say how many experiments he did," he says. "As I
know to my cost, this is such a controversial field, it is mandatory to be
as foolproof as possible."


Lionel Milgrom