This age was based on the belief that the rate of decay has been constant, and that Uranium 238 will be present in a known ratio to Uranium 235.The varying quantities of these isotopes call into question the calculated age of the solar system, since “one of the equation’s assumptions — that certain kinds of uranium always appear in the same relative quantities in meteorites — is wrong.” CAIs are “calcium-aluminum-rich inclusions” found in the meteorite.The differing amounts of material that were found in separate samplings of the same meteorite were unexpected.The current standard age assigned to the solar system of 4.6 billion years was determined by studying the Uranium-to-Lead decay systems in meteorites, which are assumed to have formed before the planets did.However, to read any clock accurately we must know where the clock was set at the beginning.Most people think that radioactive dating has proven the earth is billions of years old.Some isotopes have half lives longer than the present age of the universe, but they are still subject to the same laws of quantum physics and will eventually decay, even if doing so at a time when all remaining atoms in the universe are separated by astronomical distances.
Given isotopes are useful for dating over a range from a fraction of their half life to about four or five times their half life.Even the solar system has been dated using one of these systems, by measuring the amount of a decaying element and comparing it to the amount of its stable (decayed) daughter material in meteorites.However, a recent analysis using state-of-the-art equipment found that a basic assumption underlying one of these clock systems needs to be re-evaluated.: Suppose there is a set of variables whose individual values are probably different, and may be anything larger than zero. If there is a group of radioisotopes whose eventual decay is not predictable on the individual level, I do not understand how a decay constant is measurable. This question is asked with the intention of understanding basically the decay constant of radiometric dating (although I know the above is not an entirely accurate representation).
Gregory Brennecka of Arizona State University and colleagues measured the relative amounts of Uranium 238 to Uranium 235 from several samples taken from the large Allende meteorite, named for the village in Mexico near where it landed in 1969.