Howstuff works carbon 14 dating
How It Works: Carbon has 3 isotopic forms: Carbon-12, Carbon-13, and Carbon-14.
The numbers refer to the atomic weight, so Carbon-12 has 6 protons and 6 neutrons, Carbon-13 has 6 protons and 7 neutrons, and Carbon-14 has 6 protons and 8 neutrons.
Limitations and calibration: When Libby was first determining radiocarbon dates, he found that before 1000 BC his dates were earlier than calendar dates.
He had assumed that amounts of Carbon-14 in the atmosphere had remained constant through time.
There are two techniques for dating in archaeological sites: relative and absolute dating.
Relative dating stems from the idea that something is younger or older relative to something else.
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Learn more about hurricane categories in this How Stuff Works Illustrated video.Rodents, for example, can create havoc in a site by moving items from one context to another.Natural disasters like floods can sweep away top layers of sites to other locations.Absolute dating represents the absolute age of the sample before the present.Historical documents and calendars can be used to find such absolute dates; however, when working in a site without such documents, it is hard for absolute dates to be determined.
The Mayan calendar used 3114 BC as their reference.