Application of Nuclear Technology - Radioactive Dating

The Rock Record and the Geological Time How old is the Earth?
How old is a piece of mineral?
How old is an artifact? William Thomson (Lord Kelvin) estimated that the Earth was about 100 million years old. He estimated by trying to figure out how long is for the Earth to cool from a very hot (molten) state to the present temperatures.

Hutton believed that the Earth could be much older, because the radioactivity at the start made the cooling process slower. in 1905, he estimated the Earth to be billions year old.

Geologic Time

Relative & Absolute Dating

Application of Gamma-ray Spectroscopy

Apollo 15 Gamma-ray Spectrometer