Does water have a memory as claimed in homeopathy?

Question

In homeopathic remedies the original substance is often diluted to a point where statistically there should be not a single molecule left of the original substance. The most common explanation by homeopaths, on how it still works although there is no substance left, is that water has a memory. That the "essence" or "imprint" of a molecule can stay in water and continue to have some effect even after the molecule itself is removed.

Is this at all possible from a physical point of view?

Can water molecules (in the liquid phase) form structures that are stable over long periods of time?

Answer 1

No

Water forms strong intermolecular forces between its molecules. This is called hydrogen bonding and is a form of permanent dipole/permanent dipole interaction. Oxygen is more electronegative (its nucleus attracts a bigger share of the electron cloud of the covalent bond) than hydrogen. This causes water to form a permanent dipole where the oxygen has a small negative charge and the hydrogens have small positive charges.

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This causes electrostatic attraction between water molecules and they can form structures for a small amount of time. Other molecules in the water can affect these short lived structures and water does retain some 'memory' of these molecules.

This is how some proponents of homeopathy claim it works. This memory somehow has an opposite effect to the toxin or other chemical that was diluted, although there has not been any mechanism proposed for this.

However, the duration of the water memory has been scientifically tested and shown to be very short (less than one billionth of a second). This means that the memory has gone by the time the patient even takes the dose.

Even if water did have a long term memory, it would not prove homeopathy. There would also need to be evidence that this water memory had the medical effects that have been claimed.

Answer 2

You can't divide water indefinitely, so diluting after a certain point 1 part of the "substance" with 9 parts of water and then taking 1 part of this new solution would leave you with no molecules of the original substance.

There no physical explanation to water having "memory" when there are no molecules of the active substance sans water left in a solution.

Answer 3

I am not sure if you can call this 'Water-Memory', but a recent study by researchers at the Department of Chemical Engineering, Indian Institute of Technology, Bombay suggests that nano-particles of the original substance still persist in the solvent even after serial-dilution:

Homeopathy is controversial because medicines in high potencies such as 30c and 200c involve huge dilution factors (10⁶⁰ and 10⁴⁰⁰ respectively) which are many orders of magnitude greater than Avogadro's number, so that theoretically there should be no measurable remnants of the starting materials. No hypothesis which predicts the retention of properties of starting materials has been proposed nor has any physical entity been shown to exist in these high potency medicines. Using market samples of metal-derived medicines from reputable manufacturers, we have demonstrated for the first time by Transmission Electron Microscopy (TEM), electron diffraction and chemical analysis by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), the presence of physical entities in these extreme dilutions, in the form of nanoparticles of the starting metals and their aggregates.

Answer 4

No, no, no and no.

a) Nobody ever observed a lasting memory in water. If you look at david4dev's answer above, with the shining formula, you have to be aware, that the timespan is orders of magnitudes too small, to be the reason for anything related with medicine. And it was not known to funders of homeopathy. It can't be the source of the theory, and it can't be the cause for some observation.

b) Water has no brain. What we know, to have a memory you have to have a brain. The metaphor of a brain might be too far stretched, but mechanical memory doesn't explain anything, too. david4dev's answer shows the possibility of deducting a molecule for a very short timespan. But it doesn't show, that there is a mechanism in the human body to deduct the substance - not even if there was much more time - for example: hours.

c) Even if there was a brain in water, what would that help? I can remember an antibiotic, but that doesn't give me the effect of an antibiotic. How should it work with water? It's not an explanation. You have to think it doesn't make a difference, if something is present or if you can detect that something has been present. You can detect, that a picture has been hang on a wall for a long time, and has been removed. But that doesn't give you the picture. The whole argument is a straw man, and isn't really related to what homeopaths have claimed. There is only an associative relation via different usage of the word 'memory', and failing to understand that, should be the exclusive joy of these esoterics, it is pseudo sceptic.

d) Historically, water drops from the clouds, runs through grass and earth, runs into small and bigger rivers and lakes, later into the sea, where it is shaken and shaken, tide goes up, tide goes down :) - and intermixed with all that other water, since millions of years, and should have all information by that way already. If this would work. But of course it's nonsense.