Contamination would have to come through water flowing through the bones. Here are more quotations from the Science article referenced above: Research has been ongoing since the s to determine what the proportion of 14 C in the atmosphere has been over the past fifty thousand years. Thank you for your feedback. Thus the concentration of uranium and thorium in the dinosaur bones is near or in the normal range.
It must be then that these bones are really young.
How Do Scientists Date Ancient Things?
In all but two cases the scrolls were determined to be within years of the palaeographically determined age. Mar 14 - 7: Thus nearly 10 percent of the carbon would have to be contamination! Potassium is another radioactive element naturally found in your body and has a half-life of 1. The level has since dropped, as this bomb pulse or "bomb carbon" as it is sometimes called percolates into the rest of the reservoir. By measuring the ratio of carbon 14 remaining in plant or animal material, scientists can determine approximately when it died—provided it falls withinlast 40, years. He is credited to be the first scientist to suggest that the unstable carbon isotope called radiocarbon or carbon 14 might exist in living matter.