Rubbish, says Mr Gribbin: scientific theories are rooted in truth, and new theories are not merely different from old ones, but are measurably better.

ECONOMIST: History of science: Time's arrow | The

In a new study of more than 700 people who came down with colds, echinacea pills were not measurably better than placebo at speeding recovery time or reducing the severity of runny nose, sore throat, cough, and other symptoms.

CNN: Echinacea fails to curb the common cold (again)