Originally Posted by CTD
How does one obtain a pure sample of any of these elements in order to measure the curve? They'll decay while one is collecting them. One does not. Even with the "short-lived isotopes", extrapolation and indirect methodology are involved.
Please explain how obtaining a pure sample is required to obtain an accurate measure of radioactive decay. What prevents the obtaining of a sample and measuring the initial ratio of parent to daughter product, measuring the radioactive decay, then measuring the ratio of parent to daughter product again? Shouldn't that give an accurate accounting of the amount of decay of the parent isotope?

How does obtaining a less-than-pure sample prevent the measurement of the half life?

If extrapolation and indirect methodology are needed, does this automatically invalidate the results of the experiment? How so?

A faith that connot survive collision with the truth is not worth many regrets. -- Arthur C. Clarke