Radiometric dating is a method of determining the age of an artifact by assuming that on average decay rates have been constant (see below for the flaws in that assumption) and measuring the amount of radioactive decay that has occurred.Radiometric dating is mostly used to determine the age of rocks, though a particular form of radiometric dating—called Radiocarbon dating—can date wood, cloth, skeletons, and other organic material.The half-life of this process is 1.25 billion years, meaning that it can date significantly older samples.In rubidium-strontium dating a rubidium-87 isotope becomes the daughter product strontium-87.Because radiometric dating fails to satisfy standards of testability and falsifiability, claims based on radiometric dating may fail to qualify under the Daubert standard for court-admissible scientific evidence.
One assumption that can be made is that all the lead in the sample was once uranium, but if there was lead there to start with, this assumption is not valid, and any date based on that assumption will be incorrect (too old).
The half-life of rubidium-87 is 48.8 billion years, meaning it can accurately measure rocks as old as the Earth itself.
Uranium-lead dating is one of the most complicated of all dating techniques.
If there is too much daughter product(in this case nitrogen-14), age is hard to determine since the half-life does not make up a significant percentage of the material's age.
The range of practical use for carbon-14 dating is roughly a few hundred years to fifty thousand years.