Carbon dating or date
See also, on this website, articles on the ages of the geologic periods (Ages), radiometric dating (Radiometric dating), the reliability of radiometric methods (Reliability), a "time machine" for studying the distant past (Time machine) and the "uniformitarian" assumption and how it relates to evolution and the age of the earth (Uniformitarian).
Scratching around in a cave in the middle of nowhere, you find a bone.
Creationists often criticize radiocarbon dating in the context of discussions of the age of the earth.
But, as is clear even from the very brief discussion in the previous paragraph, radiocarbon dating can say nothing one way or the other about whether the earth is many millions of years old, since such dates are far beyond this method's range of resolution.
Around 99% of carbon on earth is carbon-12 – atoms with six protons and six neutrons in its nucleus.
Radiocarbon is an isotope with two extra neutrons, created by cosmic rays interacting with nitrogen in Earth's atmosphere.
For instance, creationist Walt Brown has pointed out inconsistencies in some radiocarbon dates of mammoths -- one part was dated to 40,000 years, another to 26,000 years (and wood surrounding it to 10,000 years), and yet another to between 15,000 and 21,000 years before the present epoch [Brown2001].
These researchers collected core samples 70 meters deep, and then painstakingly counted the layers, year by year, to obtain a direct record stretching back 52,000 years.In 2009, several leading researchers in the field established a detailed calibration of radiocarbon dating, based on a careful analysis of pristine corals, ranging back to approximately 50,000 years before the present epoch [Reimer2009].Here is a graph showing radiocarbon dates on the vertical axis and the calibrated age on the horizontal axis (shown here with permission from Johannes van der Plicht, one of the authors of the 2009 study).How do you find out if it’s the remains of an ancient animal that stomped the land tens of thousands of years ago or a discarded scrap from a cooking fire only a few hundred years back?An archaeologist’s staple is radiocarbon dating: judging the age of an organic sample from its carbon-14 – also known as radiocarbon – content.