Radiometric dating is possible if
Nuclear tests, nuclear reactors and the use of nuclear weapons have also changed the composition of radioisotopes in the air over the last few decades.This human nuclear activity will make precise dating of fossils from our lifetime very difficult due to contamination of the normal radioisotope composition of the earth with addition artificially produced radioactive atoms.When scientists first began to compare carbon dating data to data from tree rings, they found carbon dating provided "too-young" estimates of artifact age.Scientists now realize that production of carbon-14 has not been constant over the years, but has changed as the radiation from the sun has fluctuated.Scientists attempt to check the accuracy of carbon dating by comparing carbon dating data to data from other dating methods.Other methods scientists use include counting rock layers and tree rings.
For example, if they believed it would take 200 million years for an ammonite (somehow) to turn gradually into say a dog, then all rocks containing fossil ammonites (the “index fossil”) would be given an “age” 200 million years older than rocks containing fossils of dogs: “…
These isotopes have longer half-lives and so are found in greater abundance in older fossils.
Some of these other isotopes include: back to the last global catastrophe (i.e.
Levels of carbon-14 become difficult to measure and compare after about 50,000 years (between 8 and 9 half lives; where 1% of the original carbon-14 would remain undecayed).
The question should be whether or not carbon-14 can be used to date any artifacts at all? There are a few categories of artifacts that can be dated using carbon-14; however, they cannot be more 50,000 years old.