. "1933-12-08Z"^^ . . . "John Joly FRS (1 November 1857 \u2013 8 December 1933) was an Irish physicist, famous for his development of radiotherapy in the treatment of cancer. He is also known for developing techniques to accurately estimate the age of a geological period, based on radioactive elements present in minerals."@en . . . . "1857-11-01Z"^^ . "John Joly"@en .