Originally Posted by CTD
Ah, but it's the context that makes the intention so clear! Have a look: Russ correctly states that assumptions (plural) are involved, and in response, well see for yourself!

Originally Posted by LinearAq
Originally Posted by Russ
Too many assumptions, not enough intellectual integrity.

Let's look at that intellectual integrity.

Radioactive decay depends upon the amount of material present. That means the number of atoms that will decay at any one time depends on the number of atoms that are there. This can be expressed with the differential equation below.

[Linked Image]
This basically means that the change in the number of atoms (dN) per unit time (dt) is proportional(using the variable lambda) to the number of atoms present at that time (N).

The solution for that differential equation is:

[Linked Image] It is this equation that describes the exponential decay function.

So, the assumption that the physicists are really making in determination of the decay curves is the one that says the number of atoms decaying at any moment depends upon the number of atoms present at that moment. Admittedly, this is a statistical function but the large number of atoms present (6.02 times 10^23 atoms in 238 grams of U-238...for example) typically make it a very close approximation.

Are you saying that the assumption of radioactive decay depending upon the number of atoms present is incorrect for long-lived isotopes?

What you have left is the assumption that radioactive decay rates haven't changed over the time that Earth has existed. You and the RATE project group say that the radioactive isotope half lives have changed. Got some evidence?

See how the writer acknowledged two assumptions right after saying there was only one? First the "number of atoms" assumption, and second, the constant rate of decay.
You are misrepresenting what I said. Clearly the context for the "number of atoms" assumption was concerning the exponential shape of the radioactive decay curve. After explaining how the curve's exponential shape is determined, I then moved on to the decay rate assumption cited by Russ.

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I doubt we'll see any of the other assumptions acknowledged any time soon. Some evodate assumptions have been discussed on this very forum in the past, but nobody ever bothers much with the older threads, do they?

That's okay. Sooner or later another thread will come along, and the lurkers who peruse the latest chat exclusively will forget this one as well. It'll fade into the past.

This discussion between Russ and me was not about all the radioactive decay dating assumptions; only the determination of the radioactive decay curves.

For the lurkers, "evodate" is one of a number of made up words used by some Christians of the Young Earth belief system. These terms are then used in a derisive fashion much in keeping with their concept of WWJD.

A faith that connot survive collision with the truth is not worth many regrets. -- Arthur C. Clarke