Invented 112 years ago item dating
A plot is constructed of Pb-206/Pb-204 versus Pb-207/Pb-204.If the solar system formed from a common pool of matter, which was uniformly distributed in terms of Pb isotope ratios, then the initial plots for all objects from that pool of matter would fall on a single point.
Another possible escape mechanism is direct interaction of the solar wind with the upper atmosphere during the short periods of lower magnetic-field intensity while the field is reversing.Note that young-Earthers cannot accuse us of selective use of data -- the above table includes a significant fraction of all meteorites on which isotope dating has been attempted. 286) , less than 100 meteorites have been subjected to isotope dating, and of those about 70 yield ages with low analytical error.Further, the oldest age determinations of individual meteorites generally give concordant ages by multiple radiometric means, or multiple tests across different samples.The most direct means for calculating the Earth's age is a Pb/Pb isochron age, derived from samples of the Earth and meteorites.This involves measurement of three isotopes of lead (Pb-206, Pb-207, and either Pb-208 or Pb-204).Those which appear the most frequently in talk.origins are reproduced below: Note that these aren't necessarily the "best" or most difficult to refute of young-Earth arguments.
However, they are quite popular in modern creation-"science" literature (even though they should not be!
For example: Also note that the meteorite ages (both when dated mainly by Rb-Sr dating in groups, and by multiple means individually) are in exact agreement with the solar system "model lead age" produced earlier.
Young-Earthers have several methods which they claim to give "upper limits" to the age of the Earth, much lower than the age calculated above (usually in the thousands of years).
he generally accepted age for the Earth and the rest of the solar system is about 4.55 billion years (plus or minus about 1%).
This value is derived from several different lines of evidence.
(I believe this argument was originally put forth by Mormon young-Earther Melvin Cook, in a letter to the editor which was published in .) But helium can and does escape from the atmosphere, at rates calculated to be nearly identical to rates of production.