The barrel represents the earth's atmosphere in which the carbon accumulates. K decay also forms plenty of beta radiation. So, anything older than 50, years only has too little C14 left to make an accurate calculation of its age. But how does one know that the magnetic field has fluctuated and reversed polarity? This argument was popularized by Henry Morrisp. Site powered by Webvision. Henry Morris chose not to mention that portion of the paper!
A sample that is more than fifty thousand years old shouldn't have any measurable C
Carbon Dating Gets a Reset
This also holds true for amino acid racemisation dating AAR. However, these factors don't affect the radiocarbon dates by more than about percent, judging from the above studies. With the help of new physical and chemical dating methods, scientists are finally beginning to discover how and when archaic species became… well, us. They showed that a particle held inside the nucleus by a "potential barrier" may be able to "tunnel through" the barrier and emerge on the other side, since if the barrier is finite the wave function of the particle is not completely localized and there is a finite probability that the particle will be outside the nucleus. Over time, it decays back into nitrogen. If you want additional assurance that we have the correct half-life, then look at the close correlation between C dates and tree-ring dates after correcting for variances in C production caused by changes in the earth's magnetic field. However, unless the sponge itself disintegrates, the carbon which holds its fibers together must stay put.