Myths Dressed as Science
.....Four basic assumptions are necessary to use any radioisotope dating process as a reliable clock:
(1) The system of which the rock samples are a part must be a closed system. This is an increasingly bad assumption with the increasing age of the system.
(2) Decay rates of the isotopes used as clocks must remain constant over time. Again, this assumption becomes more tenuous with the increasing age of the system.
(3) The initial or primordial concentrations of parent and daughter in the system must be accurately known.
(4) For any system ages of long duration, it must be assumed that enough time has passed for measurable levels of the radioactive daughter to have been produced.
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