The second problem, which they just mention and then drop, is recrystallization of the carbonate.
It is well known that the calcium carbonate in bone is not very reliable for C-14 dating, because the original carbonate ions may exchange with carbonate in the groundwater that might be either too old - if it represent dissolved limestone - or too young - if it contains atmospheric carbon dioxide dissolved in rainwater.
If she isn’t interested, take the hint and move on to the next prospect. This ranks right up there with sending a thank you note for a gift and it is vital to successful flirting. Flirting is the first step to a successful relationship.
As originally devised circa 1950, radiocarbon dating was based on the assumption that the proportion of C-14 in the atmosphere has been constant over time, so that the amount of C-14 left in a sample would fall exponentially with its age.
However, C-14 dating of tree rings of known age subsequently demonstrated that this is not strictly true.
Depending on how easy it is for the gas to find such pores and work its way through them, this could take a considerable time. 38, they claim that the effect should be limited to a few years, yet on p.
40, they admit that in the case of the two medieval Finnish churches discussed below, some samples still exhibited an alkaline reaction, indicating the presence of some unreacted calcium hydroxide, approximately 700 years after their construction!
I have had a little chemical training (as an undergraduate at Caltech), and some prior familiarity with dendrocalibration, which is an important complication in the HJ paper.
Perhaps they or someone else will be able to correct me, but my reading of their paper is that although the C-14 results are certainly consistent with a 17th century colonial origin for the tower, they by no means conclusively rule out a pre-Columbian origin.
According to HJ, their tests indicate that the Tower was built not earlier than 1635 AD, and most likely in the range 1651-1679.
Architect Suzanne Carlson, writing already in 1996 in response to the 1994 Danish original of Hertz's article, persuasively refutes Hertz's architectural and historical objections: Even Johannes Brnsted, whom Hertz approvingly cites, admitted that "the Romanesque lines of the tower are so striking that if the tower stood in Europe, probably no one would contradict a date in the middle ages" (in Hertz 1997, p. Carlson argues that Chesterton Mill was in fact built as an observatory, and only much later converted to use as a mill.
Standard "dendrocalibration" curves have been constructed to compensate for this variation in atmospheric radiocarbon (e.g.