The C-14 method cannot be used on material more than about 50,000 years old because of this short half-life.
Other isotopes are used by geologists to date older material.
Before we get into the details of how radiometric dating methods are used, we need to review some preliminary concepts from chemistry.
Recall that atoms are the basic building blocks of matter.
Carbon-14 has a half-life of 5,730 ± 40 years— during the succeeding 5,730 years.
Because carbon-14 decays at this constant rate, an estimate of the date at which an organism died can be made by measuring the amount of its residual radiocarbon.
Upon death, the isotope begins to decay and after 5730±40 years half of it is gone.
Since tree rings provide an annual calendar, and some trees live for thousands of years, by C-14 dating the rings themselves one could correct the radiocarbon dates and calibrate the differences. should refer to the year the method was recognized, 1950.
The Bristlecone pine trees in the Sierra Nevada mountains made this possible and today there are international tree ring databases and agreed-upon calibration curves.
Many people have been led to believe that radiometric dating methods have proved the earth to be billions of years old.
This has caused many in the church to reevaluate the biblical creation account, specifically the meaning of the word “day” in Genesis 1.
Each radiocarbon date has a statistical probability shown by the ± number.