4 ms·
This is how it works: "Rock minerals naturally contain certain elements and not others. By the process of radioactive decay of radioactive isotopes occurring i
by elyase 13y ago
This is how it works:
"Rock minerals naturally contain certain elements and not others. By the process of radioactive decay of radioactive isotopes occurring in a rock, exotic elements can be introduced over time. By measuring the concentration of the stable end product of the decay, coupled with knowledge of the half life and initial concentration of the decaying element, the age of the rock can be calculated. Typical radioactive end products are argon from potassium-40 and lead from uranium and thorium decay."
-- Wikipedia
- pdonis 13y agoThis quote does leave out one crucial item, though (I don't know exactly which Wikipedia page you are quoting from, so I don't know if it's brought up elsewhere on the page, or on a page it links to): how do you know the initial concentration of the decaying element? (This is often asked by creationists trying to discredit radiometric dating techniques.) The answer is that, if you make some additional measurements, you can figure it out from the data, as explained in the Isochron Dating FAQ: http://www.talkorigins.org/faqs/isochron-dating.html http://www.talkorigins.org/faqs/isochron-dating.html