Feb 02 2010

6.022137 × 10^23

6.022137 × 10^23 – that’s Avogadro’s number. It’s the number of atoms or molecules of a substance in a number of grams of that substance equal to its atomic mass. So 1 gram of elemental hydrogen or 12 grams of carbon12 will have Avogadro’s number of atoms. This amount is also called a mole – so a mole of anything has Avogadro’s number of elementary particles – a mole of water has Avogadro’s number of water molecules.

Amedeo Avogadro first came up with the concept in 1811. In 1895 the number was first estimated by Josef Loschmidt, and when referring to the mass of an ideal gas is called the Loschmidt constant, but the number itself in 1909 was named in honor of Avogadro.

Samuel Hahnemann invented the principles of homeopathy (he “discovered” nothing, it turns out) in the 1790s and published his first article on the topic in 1796. So you see – Hahnemann could not have known about Avogadro’s number, in principle or in name, at least when he invented homeopathy. He died in 1843, long after the scientific community knew that his “law of infinitesimals” was rubbish.

Hahnemann claimed that the more a substance is diluted the more potent a medicine it becomes, in violation of the chemical law of mass action which dictated that chemical reactions proceed more quickly the more substrate there is. Hahnemann also advocated such extreme dilutions, still used by homeopathy today, that many of his potions vastly exceed the dilutional limit – the point beyond which there is likely not a single atom or molecule of substance remaining. That is where Avogadro comes in – there is a finite number of discrete particles of substance in a solution, and when you dilute it beyond all reason there is literally nothing left. Hahnemann missed Avogadro’s boat and spent the second half of his life denying the advances in science that rendered his fantasies nothing but nonsense.

Even more amazing is that homeopaths continue in Hahnemann’s delusion today, more than a century after Avogadro was honored for his insights.

To honor Avogadro further, and highlight the absurdity of homeopathy in the face of basic chemistry and physics, a UK group has started the 10^23 campaign. Their basic purpose is to protest continued support for homeopathy in the UK and elsewhere and to raise public awareness as to what homeopathy really is (nothing). They surmise (correctly, in my opinion) that the more people know about homeopathy the less popular it will be.

Their first major act was a mass public homeopathic suicide:

At 10:23am on January 30th, more than four hundred homeopathy sceptics nationwide took part in a mass homeopathic ‘overdose’ in protest at Boots’ continued endorsement and sale of homeopathic remedies, and to raise public awareness about the fact that homeopathic remedies have nothing in them.

Boots is a UK pharmacy chain who, in public testimony, essentially admitted that they know homeopathy is bunk but they sell it anyway because their customers want it. The homeopathic overdose was a stunt previously performed by James Randi. I think he was the first to do this, and was the inspiration for the stunt. It is a dramatic demonstration of the inactivity of homeopathic potions – take a massive “overdose” and suffer no ill effects. This is actually more than a stunt – it demonstrates the lack of a dose-response effect from homeopathic nostrums, which is convincing evidence that there is no effect.

One word of caution for anyone wishing to replicate this act – some commercial “homeopathic” products actually have active ingredients in them (they cheat). So read the label carefully before overdosing, there may be real medicine in there.

The event had great media coverage and put the 10^23 campaign on the map, and it is an excellent example of activist skepticism.

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