Andrew Millard refers to wiggle matching as a way of dealing with the flat portion of the carbon 14 calibration graph that is known as the Hallstatt plateau, named after the Hallstatt culture period in central Europe with which it coincides.
Radiocarbon dating—also known as carbon-14 dating—is a technique used by archaeologists and historians to determine the age of organic material.
In this process, nitrogen-14 (7 protons and 7 neutrons) gains a neutron and loses a proton, producing carbon-14 (6 protons and 8 neutrons).
The proportion of carbon-14 to carbon-12 in the atmosphere therefore remains relatively stable at about 1.5 parts per billion.
(The numbers 12, 13 and 14 refer to the total number of protons plus neutrons in the atom's nucleus.
On April 26, 2007 this facility celebrated 25 years of operation, during which time it had processed over 75,000 radiocarbon measurements on objects ranging from the Dead Sea Scrolls to the Shroud of Turin.One of the implied assumptions in radiocarbon dating is that levels of atmospheric carbon-14 have remained constant over time.This turns out not to be exactly true, and so there is an inherent error between a raw "radiocarbon date" and the true calendar date.Archaeologists are acutely aware of these and other potential difficulties, and take extreme care in the selection and handling of objects to be dated. In the 1970s a new technique was developed called Accelerator-based Mass Spectrometry (AMS), which counts the number of carbon-14 atoms directly.This dramatically improves accuracy, and reduces the amount of carbon required from about 10 grams to only a few milligrams.But carbon-14 is slightly radioactive: it will spontaneously decay into nitrogen-14 by emitting an anti-neutrino and an electron, with a half-life of 5730 years.The theory behind radiocarbon dating is as follows: Why doesn't the carbon-14 in the air decay along with terrestrial carbon? The trick is that radioactive carbon-14 is continually replenished in a complex reaction that involves high-energy cosmic rays striking the upper atmosphere.This means that although they are very similar chemically, they have different masses.The total mass of the isotope is indicated by the numerical superscript.Their commercial rate (in 2008) is 5.00 per sample, which somewhat limits its accessibility to chronically under-funded archeological research projects.Rachel Wood does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.