Acuracy of carbon dating laws on dating older guy
Calibration is not only done before an analysis but also on analytical results as in the case of radiocarbon dating—an analytical method that identifies the age of a material that once formed part of the biosphere by determining its carbon-14 content and tracing its age by its radioactive decay.
Carbon-14 is a naturally occurring isotope of the element carbon.
The slope of the line determines the date, and the closeness of fit is a measure of the statistical reliability of the resulting date.
Technical details on how these dates are calculated are given in Radiometric dating. As with any experimental procedure in any field of science, these measurements are subject to certain "glitches" and "anomalies," as noted in the literature.
Yet the advantage of AMS dating stated here is "can use smaller sample size", not "can give dates much farther into the past using the same sample size".
Are the machines too expensive to build one that can test larger samples?
It is also called “radiocarbon” because it is unstable and radioactive relative to carbon-12 and carbon-13.
Carbon consists of 99% carbon-12, 1% carbon-13, and about one part per million carbon-14.
To back up @Curious One - the detection limits are pretty darn small (Purdue's lab lists detecting one part in 3E14 of C14 vs C12).There are about two dozen decay pairs used for dating.Uranium 235 decay to lead has a half-life of 713 million years, so it is well suited to dating the universe.C14 is continually being created and decaying, leading to an equilibrium state in the atmosphere.When the carbon dioxide, containing C14 as well as stable C12 and C13, is taken in by plants it is no longer exposed to the intense cosmic ray bombardment in the upper atmosphere, so the carbon 14 isotope decays without being replenished.