How to solve carbon 14 dating problem
Organisms capture a certain amount of carbon-14 from the atmosphere when they are alive.By measuring the ratio of the radio isotope to non-radioactive carbon, the amount of carbon-14 decay can be worked out, thereby giving an age for the specimen in question.
#30,000-Year Limit The Lamont-Doherty group says uranium-thorium dating not only is more precise than carbon dating in some cases, but also can be used to date much older objects.Since 1947, scientists have reckoned the ages of many old objects by measuring the amounts of radioactive carbon they contain.New research shows, however, that some estimates based on carbon may have erred by thousands of years.The best gauge they have found is dendrochronology: the measurement of age by tree rings.Accurate tree ring records of age are available for a period extending 9,000 years into the past.
According to carbon dating of fossil animals and plants, the spreading and receding of great ice sheets lagged behind orbital changes by several thousand years, a delay that scientists found hard to explain. The group theorizes that large errors in carbon dating result from fluctuations in the amount of carbon 14 in the air.