Using uranium 238 in radiometric dating Xxx free chatline
We need to be sure that no lead compounds have been added to or taken away from the rock.
Given that lead compounds are fairly soluble in water, this is something that we cannot be very sure of.
Remember that the half-life is a statistical measure. In order to calculate the age of the rock, we need three other pieces of information: We need to know how fast the U turns into Pb The half-life gives us this value, provided the half-life has never altered during the lifetime of the zircon crystal.
We need to know how much Pb there was in the original rock. It is usually assumed, without justification, that the original quantity of Pb in the rock was zero.
Each step involves the elimination of either an alpha or a beta particle.
For example, if element Aa had a half-life of 1 day and we had 1, lbs.
Determining Half-Life By observing how fast U decays into lead, we can calculate the half-life of U This is a theoretical calculation, and we can therefore determine that the half-life of U is 4. If we look at some of the very small zircon crystals in granite, we can accurately measure how much U and Pb the crystal contains.
If the assumptions cannot be trusted, then the calculations based on them are unsound.
It is for this reason that creationists question radiometric dating methods and do not accept their results.