John Joly Quotes

John Joly was born in Bracknagh, County Offaly, Ireland. He was an Irish geologist and physicist who, soon after 1898, estimated the age of the Earth at 100,000,000 years. He also developed a method for extracting radium and pioneered its use in cancer treatment. He graduated in Engineering from Trinity College, Dublin in 1882. He became professor of geology and mineralogy after having served as demonstrator in civil engineering and physics. He tried to explain the formation of the Earth’s crust by convection of heat generated by radioactive decay in the Earth’s interior. He is also noted for his inventions of a thermometer, a steam calorimeter for measuring heat energy, and a photometer for measuring light frequencies. He wrote several books include: Radioactivity and geology, The birth time of the world, and Reminiscences and Anticipations. He received many awards, including Royal Medal, Boyle Medal, and Murchison Medal. He was elected a fellow of the Royal Society of London in 1892.