How reliable are radiometric dating methods for deciding the age of the Earth?

Question

Is this criticism of radiometric dating methods a valid one?

"Some radiometric dating methods completely undermine other radiometric dates too. One such example is carbon-14 (14C) dating. As long as an organism is alive it takes in 14C and 12C from the atmosphere; however when it dies, it will stop. Since 14C is radioactive (decays into 14N), the amount of 14C in a dead organism gets less and less over time. Carbon-14 dates are determined from the measured ratio of radioactive carbon-14 to normal carbon-12 (14C/12C). Used on samples which were once alive, such as wood or bone, the measured 14C/12C ratio is compared with the ratio in living things today.

Now, 14C has a derived half-life of less than 6,000 years, so it should all have decayed into nitrogen by 100,000 years, at the maximum.22 Some things, such as wood trapped in lava flows, that are said to be millions of years old by other radiometric dating methods still have 14C in them.23 If the items were really millions of years old, then they shouldn’t have any traces of 14C. Coal and diamonds, which are found in or sandwiched between rock layers allegedly millions of years old, have been shown to have 14C ages of only tens of thousands of years.24 So which date, if any, is correct? The diamonds or coal can’t be millions of years old if they have any traces of 14C still in them. So this shows that these dating methods are completely unreliable and indicates that the presumed assumptions in the methods are erroneous."

http://www.answersingenesis.org/articles/2007/05/30/how-old-is-earth#fnMark_1_13_1

Answer 1

The fact that the source from which you quoted from is using dishonest propaganda is very easy to determine with a few quick searches on any search engine. Specific claims they make are explained on several websites, and it quickly become obvious Answers in Genesis has intentionally designed the bulk of their material to mislead people.

I'll leave it to your imagination to determine why they would do such a thing.

Answer 2

Radiometric methods (in fact all measurements) have an associated error. The error calculated for most radiometric ages of the earth is plus or minus 1% or so. The dating methods themselves are much more reliable than answers in genesis would have you believe.

A casual glance at answers in genesis reveals so many lies per paragraph that the entire site in unreliable; there's no credibility here at all. If you believe any of the "science" on this site, then you've been duped, suckered, bamboozled, conned, deceived, hoodwinked, snookered, and otherwise tricked into believing a pack of lies - and nobody is going to listen to what you have to say if you and your source have zero credibility.

Work your way through these:

http://www.talkorigins.org/faqs/faq-age-...

http://www.lpl.arizona.edu/~matthewt/yec...

http://serc.carleton.edu/introgeo/earthh...

http://www.usd.edu/esci/age/creationism_...

Answer 3

In determining the age of something older than life itself, we use isotopes of other elements. In geology, most commonly used is uranium (I guess...). Uranium-238 decays into stable Lead with a half-life of 4.47 billion years. Maybe they used the same method (getting the ratio of this and that, etc.) but they observed a different element. ^^

Answer 4

I don't know anything about that line about sample contamination rendering all analyses invalid.  Doesn't work for me.  

Scientists did not set out to "prove" the earth is 4.5 billion years old.  That is just the answer that keeps coming up from hundreds and hundreds and hundreds of analyses on innumerable samples.  Basically, the evidence is what it is.  You can choose to disbelieve.

The biblical literalists act as though science is flawed or is purposefully faulty when it comes to evaluating the history of the earth, which says more about their failure to accept reality than it does about the validity of the results (apparently the literalists are perfectly happy accepting all other aspects of science).  

No true (honest and ethical) scientist purposefully uses invalid thinking or sets out to prove something that the evidence hasn't already suggested to them as being the likely answer.  They are human, and do makes errors, this is true.  Remember cold fusion?  When things seem out of whack, the entire scientific community attacks the issue to see if it is true or not.  Sometimes the things withstand repeated and intense efforts to find fault in the science.  This is the case with the age of the earth.

In the early years of geology, there was a huge debate about the age of the earth, but the evidence is so compelling that even the biggest doubters eventually accepted that the bible doesn't have much to say about the history of the earth.  And many of these scientists were deeply religious persons who abandoned that line of thinking most reluctantly.  The evidence is just too overwhelming.

In fact, many early scientists spent a lot of time and effort trying to fit science into the bible depiction, and gave it up as an impossible job, concluded the bible is not correct in that regard.

I suppose that people that can say one faulty analysis invalidates all the associated science would also think in terms of disproving part of the bible disproves the entire bible, but this is not valid thinking.

Answer 5

It depends entirely on what you want to believe. Using Libby's own equations, the earths atmosphere can be 'dated' by using carbon 14 as being roughly 10,000 years old.