C-14 is produced in the upper atmosphere when nitrogen-14 (N-14) is altered through the effects of cosmic radiation bombardment (a proton is displaced by a neutron effectively changing the nitrogen atom into a carbon isotope).
It takes another 5,730 for half of the remainder to decay, and then another 5,730 for half of what's left then to decay and so on.
The period of time that it takes for half of a sample to decay is called a "half-life." Radiocarbon oxidizes (that is, it combines with oxygen) and enters the biosphere through natural processes like breathing and eating.
This term defines the spread of ideas, traits, or people from one area to another -- not necessarily implying the movement of people, since trade and the adoption of new ideas from neighboring cultures are reasonable explanations of diffusion.
The diffusion of new ideas can come, however, from the peaceful or warlike expansion of a population into new territory.
This is how carbon dating works: Carbon is a naturally abundant element found in the atmosphere, in the earth, in the oceans, and in every living creature.
C-12 is by far the most common isotope, while only about one in a trillion carbon atoms is C-14.
His worrying about where a pot came from and what period it dated to and what that meant to the other objects buried with it were light-years away from the ideas represented in this photo dated to 1800, in which "Egyptian pots" was considered enough information for the thinking man.
Petrie was a scientific archaeologist, probably close to our first example.
Archaeology also examines many of the same topics explored by historians.
But unlike historythe study of written records such as government archives, personal correspondence, and business documentsmost of the information gathered in archaeology comes from the study of objects lying on or under the ground Archaeologists refer to the vast store of information about the human past as the archaeological record.
There are several ways to navigate through the materials.