Nucleocosmochronology
Nucleocosmochronology is the study of the evolution of the
Universe with respect to the four fundamental processes of
Nucleosynthesis. The dominant principle is that of
isotope dating by means of radioactive decay in the Uranium-Thorium system. Both of these
elements have long
half lives (~10^10 years) and are generated by a nucleosynthetic ('r') process, enabling a definitive estimate for the age of the Universe to be made.
Nucleocosmochronology has already been successfully employed to determine an upper limit of 4.56Ga for the age of our
Solar System.