How old is the Earth?

[TheDarkestOfAngels]

Ok great! Now we are getting somewhere. Thanks for answering the question. So do you also assume that all natural rates of decay have been constant?

Generally speaking, yes.
The reasons for which include that to which Chuck brought up earlier (see his quote below)
These reasons that also include the obvious matter that I have no reason or evidence to believe this to not be the case.

Both of these assumptions are sound.

1. Radioactive decay is fundamentally governed by the strong nuclear force, which also govern nuclear fusion. If there is difference in radioactive decay rate over time, that would reflect a change In strong nuclear interaction over time. This would be also reflected in the behavior of nuclear fusion in stars over time. We can directly observe that behavior of nuclear fusion in stars over time by observing stars and galaxies at different number of light years from earth, thus viewing them directly at different points in the past. We can see nuclear fusion has not changed over time, so neither has the behavior of strong nuclear interaction, and neither has radioactive decay.

2. The presence of daughter elements at the beginning is impossible because the mineral useful for such dating mostly can be demonstrated to have been melted in the past. The daughter elements of reactions most useful to radiometric dating are those which would have floated to the top, sunk to the bottom, or bubbled out of the melt, thus the melting process would have purged the material of any primordial inventory of daughter element. So the radiometric dating accurately measures how long it has been since the material last melted.