Posted: Jan 30, 2019 12:40 pm
Just A Theory wrote:
4. This is a wild misrepresentation of carbon dating. The carbon doesn't vanish after 10 half lives, it simply becomes indistinguishable from background after that time. The presence of radioactive carbon in the sample is then therefore much more likely to be explained via contamination. Note that the creationist carefully doesn't provide sources for their claims of "millions of years old" samples having C14 - this is a standard rhetorical trick that they use. In all such instances, it was later found that the C14 presence was better explained by experimental error or contamination of the sample.
I'd like to point out that this is actaully not true, and in fact it has been shown that even several hundred million year old samples contain non-neglible amounts of intrinsic C14.
That C14, however, turns out to be continously generated by neutron radiation from nearby radioactive elements in the rocklayers between which the carbon of interest(be it coal, diamond, natural gas, tars, crude oil or whatever) s found.
It was something of a mystery for a time why such old carbon sources contained C14 as it was thought (correctly) that the cosmic radiation responsible for generating atmospheric C14 could not penetrate the crust to the depths in which coal and so on is found. However, in calculating the expected C14 contents of ground fossil hydrocarbons, geologists had neglected to consider intrinsic neutron radiation generated by the slow continous decay of radioactive isotopes usually found in the types of rocks where one also find fossil hydrocarbons.
A PhD thesis was written a few years ago in which it is shown that intrinsic C14 production by neutron radiation is unavoidable and in fact does fully account for the observed levels of C14 in fossil hydrocarbons:
- C14.png (14.94 KiB) Viewed 3055 times
Of course, all of this still goes to ram a freight-train straight through the usual creationist bullshit.