Almeyda,
Arriving at 'dates' depends upon assumptions, This may be why i believe they are 'invalid' or 'unreliable' because if it could be proven then assumptions would not be needed only facts speaking for themselves.
As I have pointed out, all methods of measuring require assumptions. What is it about radiometric assumptions that render the methods invalid?
- Evolutionists generally assume the material being measured had no original 'daughter' elements in it, or they assume the amount can be accurately estimated. For example, they may assume that all of the lead in a rock was produced by the decay of its uranium.
Isochron methods do not make such an assumption. The date is derived from the slope obtained on a graph. All extra daughter elements will do is move the slope up & down relative to the xy axes without altering the slope. And since the isochron method shows good correlation with non-isochron methods we can nsay with some confidence that the potential introduced error is relatively small, anyway. Certainly nowhere near the millions of percent errors required by creationists.
- Evolutionists have also assumed that the material being measured has been in a closed system. It has often been wrongly assumed that no outside factors altered the normal ratios in the material, adding or subtracting any of the elements involved.
Again, the concordance between different methods shows this to be of minor importance. You require MILLIONS of percent differences, not fractions.
- They assume that the rate of decomposition has always remained constant - absolutely constant.
Correct, it hasn't been observed to change. You require the decay constants to alter by millions of percent, turning the earth into a nuclear inferno. If the constants have altered by as much as you need in the last 100 years, it would have been observed to alter, you think the universe is only 6,000 years old, remember. There is no evidence of this. No reason to doubt the observed constants.
Mark
There are 10 kinds of people in this world; those that understand binary, & those that don't