Radiocarbon dating of metal
The other major factor affecting the results of carbon dating is gauging the original proportion of carbon-14 itself.
Carbon dating is based on the loss of carbon-14, so, even if the present amount in a specimen can be detected accurately, we must still know how much carbon-14 the organism started with.
In short, carbon dating is as useful as any other technique, so long as it’s done properly and the results are objectively interpreted.
It is not, however, an inherently error-free or black-and-white method for dating objects.
For example, a steel spearhead cannot be carbon dated, so archaeologists might perform testing on the wooden shaft it was attached to.
This provides good information, but it only indicates how long ago that piece of wood was cut from a living tree.
As samples get older, errors are magnified, and assumptions can render carbon dating all but useless.
For example, variations in greenhouse effects and solar radiation change how much carbon-14 a living organism is exposed to, which drastically changes the “starting point” from which a radiocarbon dating test is based.
Carbon-14 normally makes up about 1 trillionth (1/1,000,000,000,000) of the earth’s atmosphere.If the spear head is dated using animal bones nearby, the accuracy of the results is entirely dependent on the assumed link between the spear head and the animal.This is perhaps the greatest point of potential error, as assumptions about dating can lead to circular reasoning, or choosing confirming results, rather than accepting a “wrong” date.Carbon dating is reliable within certain parameters but certainly not infallible.
When testing an object using radiocarbon dating, several factors have to be considered: First, carbon dating only works on matter that was once alive, and it only determines the approximate date of death for that sample.Contamination and repeatability are also factors that have to be considered with carbon dating.