Watches & clocks in the Sir David Salomons collection

About one in a trillion atoms of carbon is the radioactive isotope 14C. It is a ‘cosmogenic isotope’ produced by the interaction between atmospheric nitrogen (N) and cosmic rays. T...

‘Cosmic stopped clocks’ explains how, using isotopes that are the daughters of isotopes that no longer exist, isotope geochemistry has been able to assemble a chronology for the fo...