Radiometric Dating 101

coolvideo28 A person like FSAthe1st Is blind in one eye and can not see out the other because he is taught by the blind. The scribes and the Pharisees.

This was an excellent video, it's a shame that people in light of science are still in denial.

which isotope used in determining the age of dinosaur fossils?

@lamarjlp914 several isotopes are used at once in order to verify there has been no contamination. The odds of getting the same wrong date using to completely separate isotopes is astronomical. But anyways, there are several including the potassium-argon dating for extremely old samples.

@lamarjlp914

carbon 14

carbon 14 becomes undetectable after 65,000 years. I think they use a radon isotope to date dinosaur fossils.

Great video. As an engineer, I love the vids with lots of technical explanation. One question though: isn't assuming the initial state of the substance to be dated was a state with 100% pure initial radioactive isotope, with none of the products that'd be there after decay, a big assumption? If the rock is igneous, wouldn't there be all sorts of elements floating around in the lava at random? (obviously, either way the universe is over 6000 years old- jI'm ust wondering about the details)

When molten rock solidifies to form granite or basalt, it does so in the form of crystals. The crystals are of various types, and several of these, such as some micas, contain potassium atoms. Among these are atoms of the radioactive isotope potassium-40. When a crystal is newly formed, at the moment molten rock solidifies, there is potassium-40 but no argon. The clock is 'zeroed' in the sense that there are no argon atoms in the crystal. This can be verified by analysing fresh samples.

So, the argon sort of "boils" out, but when it's formed in-situ from radioactive decay, it's locked in?

Exactly