Radiometric dating evidence of evolution
The first of these referred to the rate of heat loss from the earth and the length of time it would have taken to form its solid crust.The second referred to such topics as the detailed shape of the earth (bulging slightly at the equator) and the dynamics of the earth-moon system.Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. 1979, 1986 © Harper Collins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 Cite This Source (rā'dē-ō-mět'rĭk) A method for determining the age of an object based on the concentration of a particular radioactive isotope contained within it.For inorganic materials, such as rocks containing the radioactive isotope rubidium, the amount of the isotope in the object is compared to the amount of the isotope's decay products (in this case strontium).The third referred to the heat of the sun, particularly the rate at which such heat is being lost, compared with the total amount of energy initially available.The first argument was completely undermined after taking into account the amount of heat generated by radioactive decay.
Roman poet Lucretius, intellectual heir to the Greek atomists, believed its formation must have been relatively recent, given that there were no records going back beyond the Trojan War.One outstanding feature of this drama is the role played by those who themselves were not, or not exclusively, geologists.Most notable is William Thomson, ennobled to become Lord Kelvin in 1892, whose theories make up an entire section of this collection.Harlow Shapley, who wrote an article in 1919 on the subject, was an astronomer, responsible for the detection of the redshift in distant nebulae and hence, indirectly, for our present concept of an expanding universe. Russell, author of the 1921 article on radioactive dating, was familiar to me for his part in developing the Hetzsprung-Russell diagram for stars, but I was surprised to discover that he was also the Russell of Russell-Saunders coupling, important in atomic structure theory. The prologue to the drama is the mid-19th century recognition of the relation between heat and other kinds of energy (see the 1857 article “Source of the Sun’s Heat”).Florian Cajori, author of the 1908 article “The Age of the Sun and the Earth,” was a historian of science and, especially, of mathematics, and Ray Lankester, whom he quotes, was a zoologist. The first act consists in a direct attack, led by Lord Kelvin, on the extreme uniformitarianism of those such as Charles Lyell, who regarded the earth as indefinitely old and who, with great foresight (or great naivety, depending on your point of view: see the third installment of the 1900 “The Age of the Earth” article by W. Sollas), assumed that physical processes would eventually be discovered to power the great engine of erosion and uplift.