[OT] Plato's Pub and Philosophical Society

[Jack Simth]

Originally posted by Imperator Fyron:
You can not use radio-isotope dating on objects that are only 20 years old. It was never designed to be used on such "young" objects, so stating that is completely irrelevant to the testing system. The eruption of Mount Saint Helens is not a valid test.

In which case there are no truly valid tests of the method, as historical records cease to become useful for such things after times that are still "young" in terms of testing radioscopic methods . . . which would imply that you are taking all the radioscopic dataing methods on faith. Wouldn't that make you religious, Fyron?

Originally posted by Imperator Fyron:

Radio-isotope dating is not meant to work on "young" objects. There are always inaccuracies in the levels of isotopes in any object. When there has been a very long time since the object was buried, these inaccuracies tend to average out, so you get relatively more accurate results. But, you can not accurately use any radio-isotope dating on objects that are less than a few thousand years old (this threshhold changes depending on what the half-life of the particular element is). That is not how the testing is designed to work. An example of this is that if an object is exposed to fire, it gets a lot more Carbon-14 in it, so it throws off the calculated age based off of Carbon-14 dating. This is part of the reason why Carbon-14 is not a good isotope to use. Another reason would be that its half-life is only a few thousand years, so it can not be used to test the age of objects that are millions of years old. This is why elements like Uranium are used for older objects; Uranium isotopes ahve very long half-lives. But, Uranium can not be used for dating of objects that are less than a few hundred thousand years old, because of the inherent inaccuracies of radio-isotope dating. This is why legitimate scientists do not use it to date "young" objects. There are some other elements that can be used for objects of different possible ages, but I do not remember what they are at the moment.

There are about a dozen that are used, essentially anything that decays in a radioactive fashon could theoretically be used for radioscopic dating. However, besides each specific method's individual problems, they all have a particular set of problematic assumptions lying at their cores:

1) Initial values of parent and daughter elements
These values haven't been observed in the distant past that the object comes from. Without these, determining the age via the half-life and the amounts of present parent and daughter products is impossible. These values are assumed, although normally based off of modern values (which may or may not be valid, but there is no way to tell)

2) Non-migration of both the parent and daughter elements.
More of the parent element produces a false young age, less produces a false old age. More of the daughter element produces a false old age, less produces a false young age. If you assume that a rock has been around for a long time, not being observed, how can anyone be certain that this migration hasn't happend? You can't.
While specimin collectors try to get samples from the field where this assumption is reasonable, the testing facility virtually always throws out much of the data from every sample because the ages resulting from that data are essentially zero. They levy charges of leaching or contamination on that portion, and throw it out. However, if the specimine collectors can't tell a contaminated sample from an uncontaminated sample, how can one tell in the lab which sample is not contaminated? They differentiate based on assumed old ages, and throw out any results that don't match that assumption. Accepting their assumption is an act of faith, yet these methods are commonly used as valid. That would make the people doing this people of faith, and thus religious (after a fashion) wouldn't it?

[ March 14, 2003, 21:33: Message edited by: Jack Simth ]