Tuesday, February 26, 2008

Radiometric Dating

On Monday, as part of his never ending quest to "prove" that the Earth can't be 4.5 billion years old, Bob was trying to credit the science of radiometric dating. Bob said:
One hundred percent of every single rock on the entire planet dates to be ages in the hundreds of thousands to millions to billions of years old. Every single one, including the ones when we saw and watched the rock be formed. There is not one time that a rock has ever been dated to be a young age, an accurate age, when we know the age.
Wow! 100% of every single rock on the entire planet. Bob sounds so sure! He couldn't be wrong! Could he?

Of course Bob is wrong! Scientists have dated the rock deposited by the eruption of Mt. Vesuvius to within 7 years of the date recorded by history. The scientists used the Argon-Argon dating method, which allows dating that is more accurate than Potassium-Argon dating.

You see, Potassium-Argon dating has its limitations, which Creationists like Bob like to exploit in to attempt to discredit radiometric dating techniques. Radioactive potassium decays to Argon with a half-life of 1,260,000,000 years. That's 1.26 billion years. With such a long half-life, it's impossible to use it to accurately date a rock that is less than 100,000 years old.

Please remember, Bob has no scientific credibility. He has never studied geology. He has no training in any scientific subject.

Bob simply regurgitates nonsense from "creation science" websites like Answers in Genesis.

He expects you to nod your head in agreement.


Irl Hudnutt said...


I, too, heard this segment and was thinking about writing about it. What Bobbo and his ilk don't realize that potassium-argon dating is only one way of determining the date of the earth. There are lots others, each consistent with the others.

Bob is just being willfully ignorant.

John B said...

For anyone interested I found an webpage from the US Geological Survey about the age of the earth:http://pubs.usgs.gov/gip/geotime/age.html
I found the first sentence of this page interesting (quote): " So far scientists have not found a way to determine the exact age of the earth directly from Earth rocks because Earth's oldest rocks have been recycled and destroyed by the process of plate tectonics". I would assume that scientists would have discarded using radiometrics by now if the whole system was based on bogus assumptions and not experimentally verified. I doubt that the vast majority of geophysists WORLDWIDE don't know diddly about their subject matter while a talk show host who used to belong to a religious cult ( Bob's earlier membership in the WorldWide Church of God) knows more than they do. I have heard Bob tauting someone named Robert Gentry who claims to be able to prove that the earth is only thousands of years old. According to Bob ,Gentry is trying to get evolutionists to debate with him on live television but hasn't had any takers. Google Robert Gentry and you will find that they are people who have refuted his young earth claims. You understand why other nations are beating the crap out of the US in science when we got people like Bob spewing this drivel.

pchemstud said...

Potassium-argon dating is only useful in dating rocks originally formed from molten rock. Hot molten rock is purged of argon (which is a gas and gases completely escape very hot liquids), allowing the radioactive dating clock to be set to zero when the eruption occurs. (Radioactive potassium present in the rock radioactively decays to argon. The argon gets trapped in the solidified rock).

Bob has been quoted as saying that ash from the relatively recent Mt. St. Helens explosion dates at billions of years. Well, duh. The ash came from OLD rocks on the mountain that were obliterated as a result of the explosion. I'd be worried if lava ejected from the Mt. St. Helens explosion was dated at billions of years. Solidified lava, but not ash.

Intellectual honesty includes carefuly evaluating your own arguments and not just coming up with arguments to win a debate. Bob is a GREAT debater, I'll give him that.