Lead uranium dating
Of course, there are many problems with such dating methods, such as parent or daughter substances entering or leaving the rock, as well as daughter product being present at the beginning.Here I want to concentrate on another source of error, namely, processes that take place within magma chambers."It was not until the 1950s that the age of the universe was finally revised and put safely beyond the age of the Earth, which had at last reached its true age of 4.56 billion years," Lewis said."Physicists suddenly gained a new respect for geologists." For the record, the universe is now thought to have debuted, at least in its latest incarnation, about 13.7 billion ago.By applying the technique to his oldest rock, Holmes proposed that the Earth was at least 1.6 billion years old.
This age is computed under the assumption that the parent substance (say, uranium) gradually decays to the daughter substance (say, lead), so the higher the ratio of lead to uranium, the older the rock must be.
By 1904 physicist Ernest Rutherford showed how this decay process could act as a clock for dating old rocks.
Meanwhile, Arthur Holmes (1890-1964) was finishing up a geology degree at the Imperial College of Science in London where he developed the technique of dating rocks using the uranium-lead method.
Most scientists today believe that life has existed on the earth for billions of years.
This belief in long ages for the earth and the existence of life is derived largely from radiometric dating.