Magician and skeptic James Randi (The Amazing Randi) has long challenged psychics to prove scientifically their abilities by winning a million dollar prize. So far the spirit talkers and the adepts tuned to ethereal vibrations have failed to win so much as a red cent. Now Randi is challenging the makers of homeopathic remedies to prove that their products cure anything at all. Again, a million dollars is at stake. 

Homeopathy is a form of quackery devised by an 18th century German physician based on the idea that "like cures like" - homeopaths expose sick people to minute quantities of natural substances which would produce the symptoms of the disease in healthy individuals. Upset stomach? Take pills with a very dilute formulation of arsenic. In fact, many homeopathic remedies are so dilute that they contain not even a single atom of the so-called active ingredient. Some homeopaths claim that the water in which the substance was diluted retains a "memory" of the substance which then exercises a therapeutic benefit. 

It's pretty clear that peddlers of homeopathic remedies are taking advantage of the placebo effect. Placebos are inert treatments (often a sugar pill) given to patients which nevertheless makes many of them feel better. Back in December, a new study reported in the journal PLoS One found that even telling patients that they were being given a pill with inert ingredients did not wash out the placebo effect. In the PLoS One study, patients suffering from irritable bowel syndrome (IBS) and who were told that they were being given a placebo experienced a reduction of symptoms after three weeks as great as those treated with the most powerful IBS drugs. 

At least the PLoS One researchers didn't lie to their patients. 

Disclosure: I was a speaker at Randi's The Amazing Meeting in Las Vegas back in 2007.