Posted: Jan 25, 2013 2:23 am
johnbrandt wrote:I remember being told sagely at a religious youth group meeting when I was about sixteen (hey, I was there for the girls and the bowling nights...), that a "team of explorers had taken a freshly killed seal and subjected it to radio carbon dating, and it showed (hahaha) that it had actually died 300 years before!". The person reading this from some religious magazine laughed and said how stupid the whole idea of carbon dating was.
I pointed out that I had never heard it being used to "date" something supposedly "freshly killed" (and how a team of "explorers" would have a radio carbon dating setup in the field was another question...), and that also, if you are talking about hundreds of thousands or millions of years, 300 years plus or minus is almost literally nothing.
A lot of the more fervent believers in the meeting could not understand how 300 years could be meaningless...but they also believed whole heartedly that the Earth was only about 6000 years old...
Actually the carbon dating of the seal (or any marine animal or plant) giving an older result is normal and expected. The C14 is produced in the upper atmosphere and mixes rapidly through the entire atmosphere but this is not the case with the C14 in the Ocean (dissolved in the form of CO2). Essentially it takes a long time for new C14 to dissolve in the Oceans and you also have older C14 mixing from the deep Ocean which gets taken up by phytoplankton at the bottom of the food chain. Marine C14 is "older" than atmospheric C14.
http://www.radiocarbon.com/marine-reservoir-effect.htm
Radiocarbon dates of a terrestrial and marine organism of equivalent age have a difference of about 400 radiocarbon years. Terrestrial organisms like trees primarily get carbon 14 from atmospheric carbon dioxide but marine organisms do not. Samples from marine organisms like shells, whales, and seals appear much older.
Your religiotard instructors would have been well aware of this but most of the sheep wouldn't