Radiometric dating planets
For teaching and sharing purposes, readers are advised to supplement these historic articles with more up-to-date ones suggested in the Related Articles and Further Reading below.Before 1955, ages for the Earth based on uranium/thorium/lead ratios were generally about a billion years younger than the currently popular 4.5 billion years. old Earth is reviewed and deficiencies of the uranium/lead method are discussed. This age has been determined with the radioactive dating technique.The precise decay rate of radioactive elements is used as a clock: the number of daughter products in one rock indicates its age.a popularly accepted “universal constant” even though the foundations on which it was based have been virtually removed.Some evidence is also presented to show that radiometric results that are in agreement with the accepted geological time scale are selectively published in preference to those results that are not in agreement.The basic theory of radiometric dating is briefly reviewed.
rely heavily on the uranium/thorium/lead radiometric dating methods.It has assumed something of the status of a universal constant to which all other data must be fitted, thus it has become common practice to assume that data which does not fit this result is either wrong or unintelligible. Lead-204, a minor isotope of common lead, has no radioactive parent and is believed to be primordial lead.Lead-206 and lead-207 are also believed to be present in primordial lead since there is insufficient uranium to account for all the lead.The oldest meteorites ever dated in the Solar System are 4,56 billion years old, the oldest minerals on Earth are 4,4 billion years old, and the oldest rocks on Earth are 4 billion years old.These ages are very consistent because the meteorites had to form before the accretion of our planet, and the Earth had to cool down before the first minerals could crystallise.