especially in absence of cross-checks by different methods, or if presented without sufficient information to judge the context in which it was obtained.
Isochron methods avoid the problems which can potentially result from both of the above assumptions.
The half-life of a radioactive isotope describes the amount of time that it takes half of the isotope in a sample to decay.
In the case of radiocarbon dating, the half-life of carbon 14 is 5,730 years.
There are over forty such techniques, each using a different radioactive element or a different way of measuring them.
It has become increasingly clear that these radiometric dating techniques agree with each other and as a whole, present a coherent picture in which the Earth was created a very long time ago.
If a sum invested gains \%$ each year how long will it be before it has doubled its value?
When an organism dies it ceases to replenish carbon in its tissues and the decay of carbon 14 to nitrogen 14 changes the ratio of carbon 12 to carbon 14.
Experts can compare the ratio of carbon 12 to carbon 14 in dead material to the ratio when the organism was alive to estimate the date of its death.
Radiocarbon dating can be used on samples of bone, cloth, wood and plant fibers.
His Ph D thesis was on isotope ratios in meteorites, including surface exposure dating.
He was employed at Caltech's Division of Geological & Planetary Sciences at the time of writing the first edition.