Carbon-14 dating is a way of determining the age of certain archeological artifacts of a biological origin up to about 50,000 years old.
It is used in dating things such as bone, cloth, wood and plant fibers that were created in the relatively recent past by human activities.
However, radioisotope dating may not work so well in the future.
Anything that dies after the 1940s, when Nuclear bombs, nuclear reactors and open-air nuclear tests started changing things, will be harder to date precisely.
A child mummy is found high in the Andes and the archaeologist says the child lived more than 2,000 years ago.
How do scientists know how old an object or human remains are?
As soon as a living organism dies, it stops taking in new carbon.
The use of various radioisotopes allows the dating of biological and geological samples with a high degree of accuracy.
He was employed at Caltech's Division of Geological & Planetary Sciences at the time of writing the first edition.
He is presently employed in the Space & Atmospheric Sciences Group at the Los Alamos National Laboratory.
(This, in turn, is caused by variations in the magnetic fields of the earth and sun, for example.) Although the ratio of radiocarbon to stable carbon in the atmosphere has varied over time, it is quite uniform around the globe at any given time because the atmosphere mixes very quickly and constantly.
Plants obtain all their carbon atoms from the atmosphere.