The "clock" starts ticking!

Here's what Joe said when I asked him what a "radioactive clock" is

That is what scientists are looking at- the clock starts ticking when the unstable element is formed in/ by the star.

One logical consequences of that is a ticking clock can be examined to tell how long it's been ticking.

Yet Joe claims that I am the one who does not understand how "rad decay" works.

To try and save himself Joe comes back with this

Umm a radioactive clock is the clock of radioactive elements.

Oh, the "clock" of radioactive elements. If we follow the link that he provides we see this interesting text:

A radioactive isotope such as potassium-40 which spontaneously decays to a stable end product at a constant rate, allowing absolute geologic age to be determined.

Oh, in the link that Joe uses to support his claim we see that absolute geologic ages can be determined! But how is that Joe? If "rad decay" does not work to determine ages?

And anyway, knowing a clock is ticking alone does not tell you how long it's been ticking for and Joe was quite clear in that "scientists look at the ticking clock".

And from another link Joe kindly provided we get this

Living corals cannot absorb thorium 230 (the fourth descendant of uranium 238), an isotope which is insoluble in water. The moment the coral dies, however, the decay of radioactive elements begins to produce thorium 230. The amount of thorium 230 allows for measurements of how long they have been dead.

Hey, so Joe, it seems that "scientists do not examine an atomic clock" at all, rather they use the various factors that change over the existence of a sample to determine it's age.

So, perhaps I'll forgive you in your ignorance your claim that you can use the "clock that starts ticking when the unstable element is formed in a star" to tell the ages of things. You can, of course. You just don't do it by looking at a "clock" in the atom as you originally seemed to have claimed.

Yet it still does not solve the puzzle of why Joe can post links to sites were they would agree that "rad decay" can indeed be used to determine the age of the earth and at the same time claim that you cannot.