Numerical dating techniques
Relative ages are assigned to rocks based on the idea that rock layers lower in the strata were deposited before rock layers that are higher.Creationists do not necessarily disagree with this concept, but it can only be applied to layers that are found in one location and/or can be determined to have been deposited in a continuous layer over a very wide area.The reason this age may not be a true age—even though it is commonly called an absolute age—is that it is based on several crucial assumptions.Most radiometric dating techniques must make three assumptions: The major problem with the first assumption is that there is no way to prove that the decay rate was not different at some point in the past.However, there are many methods that can be used to determine the age of the earth or other objects.
Certain types of rocks, especially those that form from magma (igneous), contain radioactive isotopes of different elements.
The starting isotope is called the parent and the end-product is called the daughter.
The time it takes for one half of the parent atoms to decay to the daughter atoms is called the half-life.
If any of these three conditions is not accurately known, the hourglass will give an inaccurate measure of time.
Radiometric dating is based on the fact that radioactive isotopes decay to form isotopes of different elements.