Carbon dating calendar
But other timekeeping methods exist and are still used in the modern world, circumventing the easy processing of dates and history between cultures.
Throughout history, time has been defined in a variety of ways: by everything from the current ruler, or empire, or not defined at all.
How to use Cal Pal Online: Enter a date above and click "Calibrate".
Dates between 50.000 and 1 BP will be calibrated using the calibration curve Cal Pal2007_HULU.
Radiocarbon or 14C (pronounced "carbon fourteen") is a radioactive form of carbon. This means that an organism that died 5,700 years ago will have only one half of its original 14C.
Normal 12C has 6 protons and 6 neutrons, whereas 14C has 6 protons and 8 neutrons. An organism that died 11,400 years ago will have only one quarter of its original 14C, and so on.
Ancient texts and carvings from the Mayan culture describe rulers and great events and attribute the dates according to a complex system denoted by dots and bars, known as the Long Count.
The study, published in , backs up previous carbon-dating studies, and supports the hypothesis that climate change played an important role in the development and demise of this complex civilisation, say the researchers.
For periods without a historic record, attempts have been made to categorize tool kits, pottery styles, and architectural forms into regional timelines.
Some ill-fated attempts to define time even attempted to count backwards through the genealogies of the Bible, establishing a series of dates which remain a cause of confusion.
When it comes to dating archaeological samples, several timescale problems arise.
For example, Christian time counts the birth of Christ as the beginning, AD 1 (Anno Domini); everything that occurred before Christ is counted backwards from AD as BC (Before Christ).