Carbon dating tree buried in layers
On the surface, radiometric dating methods appear to give powerful support to the statement that life has existed on the earth for hundreds of millions, even billions, of years.
However, because radiocarbon decays relatively rapidly, it is only useful in practice up to about 50,000 years.3 Thus most fossils, being regarded as millions of years old, are never tested for radiocarbon, because they are not supposed to have any left.Scientists use a technique called radiometric dating to estimate the ages of rocks, fossils, and the earth.Many people have been led to believe that radiometric dating methods have proved the earth to be billions of years old.Rasmus Nyerup's quote reminds us of the tremendous scientific advances which have taken place in the 20th century.In Nyerup's time, archaeologists could date the past only by using recorded histories, which in Europe were based mainly on the Egyptian calendar.So when fossils are found in sedimentary rock layers, they are identified within the context of where they fit in the evolutionary ‘tree of life’, and a millions-of-years ‘age’ is therefore assigned to the fossil and the rock accordingly.2 In recent years a variety of techniques have been developed to ‘date’ some rocks and minerals using the decay of radioactive elements in them.
These methods include potassium-argon, rubidium-strontium, uranium-thorium-lead and samarium-neodymium dating.
We know that it is older than Christendom, but whether by a couple of years or a couple of centuries, or even by more than a millenium, we can do no more than guess." [Rasmus Nyerup, (Danish antiquarian), 1802 (in Trigger, 19)].
The person who wrote these words lived in the 1800s, many years before archaeologists could accurately date materials from archaeological sites using scientific methods.
They used pottery and other materials in sites to date 'relatively'.
They thought that sites which had the same kinds of pots and tools would be the same age.
Welcome to the K12 section of the Radiocarbon WEBinfo site.