The level of atmospheric C is not constant due to human activity, in part because of human combustion of fossil fuels and in part because of above-ground testing of the largely defensive weapon of the thermonuclear bomb.
Therefore dates must be calibrated based on Indeed, this results from a unique decay mode known as "cluster decay" where a given isotope emits a particle heavier than an alpha particle (radium-226 is an example.) This fact is extremely inconvenient and is therefore usually omitted in creationist literature.
The majority of Egyptologists agree on the outline and many details of the chronology of Ancient Egypt.
This scholarly consensus is the so-called Conventional Egyptian chronology, which places the beginning of the Old Kingdom in the 27th century BC, the beginning of the Middle Kingdom in the 21st century BC and the beginning of the New Kingdom in the mid-16th century BC.
This was most pervasive before the mid 19th century, when Manetho's figures were recognized as conflicting with biblical chronology based on Old Testament references to Egypt (see Pharaohs in the Bible).
In the 20th century, such biblical bias has mostly been confined to alternative chronologies outside of scholarly mainstream.
Carbon dating has a certain margin of error, usually depending on the age and material of the sample used.
Carbon-14 has a half-life of about 5730 years, and therefore it is used to date biological samples up to about 60,000 years in the past.The sed festival was usually celebrated on the thirtieth anniversary of the Pharaoh's ascension, thus rulers who recorded recording one could be assumed to have ruled at least 30 years.However, once again, this may not be the usual practice in all cases.For example, Breasted adds a ruler in the Twentieth dynasty that further research showed did not exist.Following Manetho, Breasted also believed all the dynasties were sequential, whereas it is now known that several existed at the same time.This is illustrated by comparing the chronology as given by two Egyptologists, the first writing in 1906, the second in 2000 (all dates in the table are BC).