Five things that modern science cannot explain:

[bananas]

32. No, placebo is not "the null effect", placebo is not "doing nothing"

In scientific research, "doing nothing" is called "no treatment", not "placebo".

There are also well documented differences between active placebos and passive placebos, even though most placebo-controlled studies use only passive placebos.

Even color, shape, and size of the pill affects the effectiveness of both "real" drugs prospective treatments as well as placebos.

http://en.wikipedia.org/wiki/Placebo

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A placebo described as a muscle relaxant will cause muscle relaxation and, if described as the opposite, muscle tension.[47] A placebo presented as a stimulant will have this effect on heart rhythm, and blood pressure, but, when administered as a depressant, the opposite effect.(48) The perceived consumption of caffeine has been reported to cause similar effects even when decaffeinated coffee is consumed,(49,50) although a 2003 study found only limited support for this.(51) Placebos represented as alcohol can cause intoxication(52) and sensorimotor impairment.(53) Perceived ergogenic aids can increase endurance,(54) speed(55) and weight-lifting ability,(56) leading to the question of whether placebos should be allowed in sport competition.(57) Placebos can help smokers quit.(58) Perceived allergens that are not truly allergenic can cause allergies.(59) Interventions such as psychotherapy can have placebo effects.(60)pp 164–173 The effect has been observed in the transplantation of human embryonic neurons into the brains of those with advanced Parkinson's disease.(61)

Because placebos are dependent upon perception and expectation, various factors that change the perception can increase the magnitude of the placebo response. For example, studies have found that the color and size of the placebo pill makes a difference, with "hot-colored" pills working better as stimulants while "cool-colored" pills work better as depressants. Capsules rather than tablets seem to be more effective, and size can make a difference.(62) One researcher has found that big pills increase the effect(63) while another has argued that the effect is dependent upon cultural background.(64) More pills,(65) branding,(66) past experience,(67) and high price(68) increase the effect of placebo pills. Injection(69) and acupuncture(18) have larger effect than pills. Proper adherence to placebos is associated with decreased mortality.(70)

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