Write notes on radiocarbon dating
The program used to convert BP to BCE dates is Ox Cal, which is accessible free for anyone at the website of the Oxford Radiocarbon Accelerator Unit.
Another kind of calibration seems to be necessary for radiocarbon dates taken on human bones, It has long been recognized that in salt-water seas, organic substances like shell or fish bones absorb old carbon that is in solution in the water, which makes radiocarbon dates on shell and fish come out too old.
Dates measured on charcoal or the bones of horses and sheep are not affected, because wood and grazing animals do not absorb carbon directly from water like fish do, and they do not eat fish.
Dates on human bone can come out centuries older than dates measured on animal bone or charcoal (this is how the problem was recognized) if the human ate a lot of fish.
Fish absorb old carbon in solution in fresh water, and people who eat a lot of fish will digest that old carbon and use it to build their bones.
Calibrated dates are “real” dates, measured in “real” years.
This is called the “reservoir effect” because seas act as a reservoir of old carbon.
Recent studies have indicated that the same problem can affect organisms that lived in fresh water, and most important among these were fish.
To be able to do this lesson and understand the idea of half-life, students should understand ratios and the multiplication of fractions, and be somewhat comfortable with probability.
For the laboratory portion of this lesson, you will have to set up the ring stands, rings, funnels, and graduated cylinders.