Radio dating fossils
Later, after radioactivity had been proven to be a significant source of the Earth's internal heat, he did privately admit that he might have been in error.
Of course, this was a close as Kelvin ever came to publicly recanting his position.Chamberlain (1899) pointed out that Kelvin's calculations were only as good as the assumptions on which they were based."The fascinating impressiveness of rigorous mathematical analyses, with its atmosphere of precision and elegance, should not blind us to the defects of the premises that condition the whole process.Both the physical geologists and paleontologists could point to evidence that much more time was needed to produce what they saw in the stratigraphic and fossil records.As one answer to his critics, Kelvin produced a completely independent estimate -- this time for the age of the Sun.
Based on these assumptions he at first suggested an age of the Earth of between 100 Ma and 500 Ma.