Compare and contrast relative and radioactive dating
Most people accept the current old-earth (OE) age estimate of around 4.6 billion years.This age is obtained from radiometric dating and is assumed by evolutionists to provide a sufficiently long time-frame for Darwinian evolution.One problem with earth dating is that the original earth surface is assumed to have eroded long ago.But assuming the earth was formed at the time of the rest of our solar system, then recovered moon rock and meteorites can also be used to estimate the age of the earth.The time required for half the original number of parent atoms to decay is called the half life.Some half-lives are listed below: It follows that uranium-lead, potassium-argon (K-Ar), and Rubidium-Strontium (Rb-Sr) decay can be used for very long time periods, whilst radiocarbon dating can only be used up to about 70,000 years. This uses a simple exponential decay formula linking the original number, Po, of parent atoms in rocks and minerals to the P atoms now present, thereby enabling an estimate of geological age.The earth precesses (wobbles like a spinning top) around the sun in a series of cycles.These cycles affect sunlight and hence long-term can form layers in rock.
Similarly, annual lake sediments can be used to estimate relative age and conventional interpretation for the Green River varves suggests they have been formed over some 20 million years.
In other words, half of the radioactive isotope in a sample would have decayed to Nitrogen-14 (N-14) in just 5,730 years.
C-14 dating of carbon-bearing materials is therefore limited to roughly 50,000 years.
In fact, organic samples from every portion of the Phanerozoic record (spanning the last 500 million years on OE dating) show detectable amounts of C-14.
The implication is that this organic material was either contaminated by new C-14, or it was buried much more recently and OE dating methods are suspect.In some cases these astronomical cycles in rock appear to have been laid down over some 25 million years (and radiometric dating puts the absolute age of the rock at some 200 million years).