Origins TheologyForum for the discussion of Creation Science (Young/Old) vs Theistic Evolution. Discussion of Atheistic Evolution should be taken to the Discussion and Debate forums.
Wow. There are still people fighting about radiometric dating? Why? Do you think that we are stupid enough to not know how atomic decay happens?
Atomic decay is not what is being questioned on this. What is being questioned is the samples being evaluated to be prestine over time without things to effect that decay. Contamination can effect decay rate substantially and near by radioactive sources could as well.
There has to be some major assumptions made for radiometric dating to be valid. Heres a few of them:
1. What ever system produced the sample had to be essentially a closed system with no chance of contamination.
2. What ever system produced the sample had to initially contain no daughter products from the radioactive decay.
3. The decay process has to be constant thru out time.
4. The clock for the sample had to start at a beginning when no daughter products existed i.e. all of the U238 in the world had no Pb206 in or near it and no Pb 206 existed anywhere in the world.
These are just a few I could come up with a lot more. Here's the bottom line to my way of thinking. If this modality is to be taken seriously then it certainly cannot be used on a dynamic planet like earth where the norm is change, why? Because you cannot base a scientific certaintity on something that requires that many unknown assumptions to be valid.
Regardless, for the sake of argument, I'll accept the hearsay you quoted as true. You still have not accounted for the sequential mammillary coatings found up and down the canyon walls. These cannot be ignored since they cannot form overnight in turbid waters.
You seems to be very interested in the mammillary coating argument. It is dangerous to hold any argument based only on one piece of work. Do you want to talk more about this article with me? Or you rather walk me out of the game again?
The major problem about the article is on its assumption: the level of water table was contemporary with the river channel (of the Colorado River). U-Pb, U-U dating work on that work is one matter and the "interpretation" on the erosion speed of Colorado River is another matter. They tie these two together by the major assumption. It is a premature argument.
Now to the "mamillary coatings" you mentioned. It appears these are uranium/lead isotope based and they measure this by the standard radiometric dating methods and ratios. The only thing new is these particular mamillary crystals and their uniqueness. I have already mentioned the questionability of radiometric dating in the past. There are just too many assumptions that have to be made for radiometric dating to be valid. When I first started to question these modalities in a serious way I was reading up on some dating samples taken from fresh magma just extruded from a volcano. They dated this stuff at several billions of years old. Anyway, to me the fact that there are little or no erosional features in the lateral stratas is much more indicative of very rapid deposition.
Jim, a little background information for you:
This so called mammillary coating is nothing special but is a form of common stalactite, which is normally found in cave deposit. They called it "coating" because it is quite small (initial stage of growth) compare to normal stalactite. The small size of this cave and its deposit are where the problems lie. A simple way to see it is that the caves are very very young (no older than modern lime deposit dripped from a bridge). Of course, the U-Pb dating said otherwise. Regardless how would this work related to the canyon development, the age of the cave deposit itself is an interesting thing to think about. A common sense said that those small caves in the canyon area are not likely older than the Pleistocene age.
1. What ever system produced the sample had to be essentially a closed system with no chance of contamination.
2. What ever system produced the sample had to initially contain no daughter products from the radioactive decay.
Zircon crystals chemically REJECT Pb. This property makes them an isolated system when doing U-Pb dating.
3. The decay process has to be constant thru out time.
There are two isotopes of U and Pb that is used in U-Pb dating.
U238 decays into Pb206 and U235 decays into Pb207 at different rates. If any contamination or the rates of decay slowed down, we would have seen it because the ratios of parent and daughter isotopes would have been off rendering conflicting dates.
4. The clock for the sample had to start at a beginning when no daughter products existed i.e. all of the U238 in the world had no Pb206 in or near it and no Pb 206 existed anywhere in the world.
No, there just can’t be any Pb in the sample at the time of formation. Zircon crystals take care of that because it is impossible for Pb to enter the structure.
Goodness! There's so much to this? Is there a book or website that offers Earth Dating 101? I'd like to know more but I need a glossary for Pb, etc. Hehe.
Goodness! There's so much to this? Is there a book or website that offers Earth Dating 101? I'd like to know more but I need a glossary for Pb, etc. Hehe.
This USGS publication is primarily about plate tectonics, but contains a wealth of information about how the Earth is dated in very simple terms that the layman can understand. http://pubs.usgs.gov/gip/dynamic/dynamic.html
__________________ (The Library of Alexandria) questioned the permanence of the stars, but did not question the justice of slavery - Carl Sagan in Cosmos
This USGS publication is primarily about plate tectonics, but contains a wealth of information about how the Earth is dated in very simple terms that the layman can understand. http://pubs.usgs.gov/gip/dynamic/dynamic.html
Thanks, I've put the link in my gmail for future reference.
Zircon crystals chemically REJECT Pb. This property makes them an isolated system when doing U-Pb dating.
Isolated from the environment? I don't think so. Even large fluctuations in the relative saturation of H2O or large changes in pressure in the atmosphere could change the rate. There are other things that can cause a false interpretation of age or rate of decay as well. For instance any change in high energy particle bombardment of neutrinos, mesons, or cosmic rays from the Van Allen belt would drastically change the rate.
Without knowing what existed in times past we can't make these determinations without making some large assumptions.
Thanks, I've put the link in my gmail for future reference.
One simple guideline to remember is that there are more wrong answers than right answers. So, if there are two, three, four or more independent tests all giving the same date, it is likely to be correct.
If the decay rate had been corrupted by the various problems that can arise, independent tests would give wrong answers, but they would probably give different wrong answers.
There are a lot of things that would have to go wrong for all independent tests to be wrong. And it is extremely improbable that being wrong, they would all point to the same wrong date.
__________________ The high, the low, all of creation God gives to humankind to use. If this privilege is misused, God's Justice permits creation to punish humanity~~ Hildegard of Bingen cited in, Earth Prayers from around the World
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