Potassium argon dating simplified
When 40K decays radioactively, it produces both 40Ar (argon) and 40Ca (calcium), with a half-life of 1.25 billion years.For example, imagine you crsytallize a rock with 1 gram of 40K (and no 40Ar).For now, I wanted to consider an older article, only a page long, entitled "How do you date a New Zealand volcano?" Although the article was not published by any member of the RATE team, it provides a simple example of Ai G's critical approach: 1) remind readers that several assumptions are inherent to radiometric dating methods; 2) provide a case-in-point where at least one of those assumptions was falsified; 3) extrapolate the proven uncertainty to the rest of geochronology without qualification; 4) (optional) advise readers that anyone defending radiometric dating methods is trying to undermine God's clear teaching of a young Earth and, consequently, the gospel itself.If you came back after 1.25 billion years, and assuming nobody has heated the rock or altered it chemically, you would find 1/2 grams of 40K and 1/2 grams of 40Ar/40Ca.After another 1.25 billion years, you should find 1/4 grams of 40K and 3/4 grams of 40Ar/40Ca.
Over the years, Answers in Genesis has committed to undermining the credibility of radiometric dating techniques.
In this sense, it is much like estimating the origin of a cannonball in flight, using a set of physical observations and the laws of gravity.
Secondly, radiometric dating methods (K-Ar in particular) do not estimate the age of a rock, but the time at which a mineral in that rock was last near a given temperature (called the closing temperature).
Since neutrons have no charge, they don't affect the chemical behavior of an element (besides its mass).
Therefore, any mineral that contains potassium (K) will contain a mixture of all its isotopes (39, 40, and 41).
Less than 1% of this potassium occurs as 40K, which is the radioactive isotope.