current community

your communities

more stack exchange communities

Stack Exchange
tour help
Take the 2-minute tour ×
Skeptics Stack Exchange is a question and answer site for scientific skepticism. It's 100% free, no registration required.
up vote 50 down vote favorite
4

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?

share|improve this question
    
Does homeopathy require the use of pure distilled water? If not then it's a slightly different thing since non-pure water would have other things in it –  Russell Steen Feb 24 '11 at 23:43
    
@Russell - I believe the solvent is supposed to be pure, yes. –  Shinrai Feb 24 '11 at 23:45
9  
if that were true (if homeopathy works), you could cure any disease with tapwater, since it probably will have been in contact with every kind of material in it's existence –  oɔɯǝɹ Mar 19 '11 at 23:35
2  
@shinrai At risk of going further off-topic here, Wikipedia mentions distilling water is described as early as 200 CE. en.wikipedia.org/wiki/Distilled_water That said, you can distill water with nothing more than a fire, a big shell (for boiling sea water), an animal skin (for collecting water vapor/steam), and a cocoanut (for collecting the fresh water). It does't take much in the way of technology to do it. (evaporative distilling is even easier) –  Ustice Mar 29 '11 at 14:15
5  
There's less arsenic in a 30C arsenic solution than there is Oliver Cromwell's urine in a glass of London tap water. Do homeopath believers only drink distilled water? Oh, and whenever anyone mentions homeopaths, there must be a link to this: youtube.com/watch?v=HMGIbOGu8q0 –  Skizz Mar 29 '11 at 17:18

1 Answer 1

up vote 100 down vote accepted

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.

hydrogen bondingFile:Hydrogen-bonding-in-water-2D.png

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.

share|improve this answer

The central argument of this answer is theoretical in nature. We do not allow answers based uniquely on common sense or pure logic. Answers which are wholly based on a theoretical model are generally downvoted and may be deleted. See FAQ: What are theoretical answers?
    
So you would claim that for less than the billionth part of a second, if a molecule of something is taken away from some water this something could be identified, just by the electrostatic structure in a very, very short region? But that doesn't fit to homeopathic claims, if they sell this to slow human beings? If they dilute and dilute the water? That doesn't fit. –  user unknown Feb 25 '11 at 1:18
3  
@user unknown - My answer clearly shows I have no belief in homoeopathy and why. Some believers of homoeopathy claim this 'water memory' to be how it works. I have shown with scientific evidence that this can't be the case. This is not a stawman argument because I haven't misrepresented any opinions. The 'wonderful formula' is a simplified diagram that I used to try to explain the underlying science and is not to 'fool the voters'. I don't want to assume everyone has A level Chemisty knowledge so I needed a way to explain hydrogen bonding simply. –  david4dev Aug 10 '11 at 6:31
1  
Homeopaths use the word 'memory' in a very different sense. They don't claim, that you can deduce which molecules have been in contact some time before, but they claim, that the water overtakes the effect, the liquid would have, if the molecules where still inside. I understand the work, cited by you, in that way, that there is a kind of imprint, a counterpart of the substance in the water. I see that you clearly don't believe in homeopathy, and why, and I appreciate it, but I don't vote on your habitus against homeopathy, but on my impression, whether your answer matches the question. –  user unknown Aug 10 '11 at 18:46
1  
It's trival to prove this answer wrong. Take a pot of water and put your hand into it and take it out. It will take a lot longer than one billionth of a second till the water reaches it's orginal state. Water is clearly able to retain some information for longer than one billionth of a second. More seriously, if the logic of the answer would be true there wouldn't be any hurricanes. Additional we aren't talking about pure H_2O. –  Christian Jan 4 '13 at 18:22
2  
@Christian if you have an answer to the question that is contrary to this response and evidenced backed, I would be very interested in seeing you post an answer yourself. –  Kaz Dragon Jan 7 '13 at 13:58

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.