The story of radiocarbon dating shows science at its finest.When I first got involved in the creationism/evolution controversy, back in early 1995, I looked around for an article or book that explained radiometric dating in a way that nonscientists could understand. Young-Earth creationists -- that is, creationists who believe that Earth is no more than 10,000 years old -- are fond of attacking radiometric dating methods as being full of inaccuracies and riddled with sources of error. All these methods point to Earth being very, very old -- several billions of years old. Radiometric dating methods are the strongest direct evidence that geologists have for the age of the Earth.When I first became interested in the creation-evolution debate, in late 1994, I looked around for sources that clearly and simply explained what radiometric dating is and why young-Earth creationists are driven to discredit it.The second assumption is that the organism in question got its carbon from the atmosphere.A third is that the thing has remained closed to C14 since the organism from which it was created died.When we know how much has decayed, we know how old the sample is.Many archaeological sites have been dated by applying radiocarbon dating to samples of bone, wood, or cloth found there. One is that the thing being dated is organic in origin.Some isotopes can break down in more than one way -- in these cases, each different breakdown type has its own half-life.The decay rate and therefore the half-life are fixed characteristics of an isotope. That's the first axiom of radiometric dating techniques: the half-life of a given isotope is a constant.