The relative width of the red calibration curve indicates the range of uncertainty: In October 2012, a team led by Christopher Ramsey of Oxford University published a new study, based on analyses of varves (alternating light/dark bands in sediments) from Lake Suigetsu, which is located about 350 kilometers west of Tokyo, near the coast of the Sea of Japan.

For instance, even in the 1950s, when Willard Libby first developed the process, it was recognized that the scheme assumes that the level of carbon-14 in the atmosphere is constant.

But, as is clear even from the very brief discussion in the previous paragraph, radiocarbon dating can say nothing one way or the other about whether the earth is many millions of years old, since such dates are far beyond this method's range of resolution.

Because of this relatively short half-life, radiocarbon is useful for dating items of a relatively recent vintage, as far back as roughly 50,000 years before the present epoch.

Radiocarbon dating cannot be used for older specimens, because so little carbon-14 remains in samples that it cannot be reliably measured.

Radiocarbon dating, which is also known as carbon-14 dating, is one widely used radiometric dating scheme to determine dates of ancient artifacts.

In discussions of the age of the earth and the antiquity of the human race, creationists often assail perceived weaknesses in radiocarbon dating. Morris, for instance, wrote, "Despite its high popularity, [radiocarbon dating] involves a number of doubtful assumptions, some of which are sufficiently serious to make its results for all ages exceeding about 2000 or 3000 years, in serious need of revision." [Morris2000, pg. Radiocarbon dating is based on the fact that the interaction of cosmic rays from outer space with nitrogen atoms in the atmosphere produces an unstable isotope of carbon, namely radiocarbon.

Since it is chemically indistinguishable from the stable isotopes of carbon (carbon-12 and carbon-13), radiocarbon is taken by plants during photosynthesis and then ingested by animals regularly throughout their lifetimes.When a plant or animal organism dies, however, the exchange of radiocarbon from the atmosphere and the biosphere stops, and the amount of radiocarbon gradually decreases, with a half-life of approximately 5730 years.In 2009, several leading researchers in the field established a detailed calibration of radiocarbon dating, based on a careful analysis of pristine corals, ranging back to approximately 50,000 years before the present epoch [Reimer2009].Here is a graph showing radiocarbon dates on the vertical axis and the calibrated age on the horizontal axis (shown here with permission from Johannes van der Plicht, one of the authors of the 2009 study).Thus creationists and others who invoke perceived weaknesses in radiocarbon dating as justification to cast doubt on the great age of the earth are either uniformed on very basic scientific facts, or else are highly being disingenuous to their audience.Radiocarbon dating has been studied at great length over the past few decades, and its strengths and weaknesses are very well understood at this point in time.