What process is radiometric dating based on
Most people are not aware of the many processes that take place in lava before it erupts and as it solidifies, processes that can have a tremendous influence on daughter to parent ratios.
Carbon dating is used to determine the age of biological artifacts up to 50,000 years old.
Each isotope is identified with what is called a ‘mass number’.
When ‘parent’ uranium-238 decays, for example, it produces subatomic particles, energy and ‘daughter’ lead-206.
The first is that atoms have always decayed at the same rate.
And this isn’t really an assumption as the decay rates have been tested in the laboratory for a hundred years or so, we have an example of a natural nuclear reactor where we can measure the various products and determine the decay rates (and the fine structure constant), and we can observe the past by looking deep into the past of the universe. The sigh isn’t for the effort of writing, it’s for the effort of finding all the references.
Most scientists today believe that life has existed on the earth for billions of years.
(Aside, my dad doesn’t know how old I am, he usually misses by about two years, giving him an error of almost 5%.) Not only, is this not a ‘false assumption’. Oh and here’s a link to the Table of Contents for this set of creationist misconceptions.
Geologists often need to know the age of material that they find.
Isotopes are important to geologists because each radioactive element decays at a constant rate, which is unique to that element.
Prior to 1905 the best and most accepted age of the Earth was that proposed by Lord Kelvin based on the amount of time necessary for the Earth to cool to its present temperature from a completely liquid state.