Saturday 28th July 2007

What's the truth about carbon-dating

Rarely a week goes by without someone emailing me with a comment similar to the following: "They have found some fossils near where I live and have carbon-dated them to be 100 million years old". There is a lot to be written about dating methods-and many articles on the subject appear on the Answers in Genesis website-but what I am more concerned about in this article is, why do so many people believe that carbon-dating has dated fossils to be millions of years old. The evolutionary scientists themselves have never said that carbon-dating has been used on fossils; so why do people in the media and on the street think that they have?

Carbon-dating is not a measure of all the carbon. Carbon exists in a number of different types, called isotopes, which have different masses, depending on the number of neutrons in the nucleus. In carbon, the main isotopes have mass numbers of 12, 13 and 14 respectively. There is little of interest in what is by far the most common and stable kind, carbon-12. Carbon-13 is also stable, radioactively, but carbon-14 is radioactive. Atoms of carbon-14 are produced in the atmosphere by neutron bombardment of atoms of nitrogen-14. The carbon-14 so produced decays by β-decay back into nitrogen-14. This decay process follows a mathematical rule, depending on the length of the so-called half-life. For example, suppose there were 100g of a substance with a half-life of ten minutes. Ten minutes later there would be 50g. After another 10 minutes, there would be 25g left. After yet another 10 minutes, there would be just 12.5g left. Carbon-14 has a calculated half-life of about 5700 years. This is calculated, because, obviously, no one has been measuring it for that long. So, if the amount of carbon-14 in the newly dead organism is known, and the present measured amount, then it would be possible to calculate how long ago the organism died-in a live organism, it is assumed that the proportion of carbon-14 always remains constant, because there will be continuous input of carbon from carbon dioxide or food.

With any radioactive decay measurement, no trace of the parent atoms can be detected after ten half-lives. It follows that carbon-dating cannot be used for anything that might have died more than about 57000 years ago. This clearly gives the lie to the statement that a supposed 100 million-year-old fossil were dated by carbon-dating.

Interestingly, some diamonds have been tested for carbon-dating. The diamonds are supposedly more than a billion years old. As diamond structures are too tight for even a bacterium to enter, they should not contain any trace of carbon-14. The fact that they do indeed contain measurable amounts of carbon-14 suggest that they are a good deal younger than the billion years claimed, and certainly must be less than 57000 years old. This does not prove a biblical age of 6000 years, but it is certainly consistent with that position.

Of course, serious evolutionary scientists do not make such mistaken claims about fossil dating, yet 'popular' TV science programmes frequently make such errors. Yet such is society's conditioned bias in favour of evolutionary ideas, that when I correct such emailed opinions, the senders rarely accept the logic of real science. Real science is always gratifyingly consistent with the Bible.

The opinions expressed in this article are not necessarily those held by Cross Rhythms. Any expressed views were accurate at the time of publishing but may or may not reflect the views of the individuals concerned at a later date.

About Paul Taylor

Paul Taylor is Head of Media and Publications at Answers in Genesis (UK/Europe). He read chemistry at Nottingham University and taught science for 17 years, eventually becoming a Head of Department, and gaining a Masters degree in Science Education at Cardiff University.

In January 2005, he published his first book, Just Six Days, in which he arranged contemporary creationist thinking into biblical order as a commentary of Genesis chapters 1 to 11.

Paul joined the staff of AiG-UK in August 2005. He is a regular contributor to the AiG website and is in demand as an itinerant speaker and media commentator, as well as writing numerous articles, many of which are published in various Christian magazines.

View all articles by Paul Taylor

Reader Comments

Posted by vic in tampa, fl @ 11:07 on Aug 3 2010

if only evolutionists could hear themselves talk. every single lie creationists are accused of are shamelessly perpetrated by secular scientists. one guy even acts like the catholic church is christian and uses that fallacy to indict creationists. but thats the kind of ignorance we're up against. summer is an ignorant liar, who assumes that a "real" scientist wouldn't agree with the writer(by real she means a God hating biased evolutionist). rick starr fares no better when he says that
"Um, it's not vaguely consistent with that position. Even if it is "less" than 57,000 years old, it might be 51,000 years old, which is nowhere close to the 6,000 year figure Bible literalists claim. There is a lot more room for "Bzzt. WRONG" than "certainly consistent" there." The point was that the dates were hopelessly off but because it didn't implicitly say 6000 yrs, in his addled naturalistic philosophy, he claims some kind of "victory" when in actuality his faith was dealt a huge blow. The fact is not a single person starts out without presuppostions or assumptions. Evos' are just more rampant and ridiculous and above all, unprovable.

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Posted by Jacob Andrew Hartman in Memphis, TN @ 09:37 on Jul 10 2010

The fool hath said in his heart; "there is no GOD", they are corrupt, they have done abominable works, there is none that doeth good. (PSALM14:1)
~Thank you Paul, for once again, TRUE science is proving everything that the antitheist despises to know. The Fear of The LORD is the beginning of knowledge, FOOLS despise wisdom and instruction.(PROVERBS1:7) Science is everyday proving the HOLY TRUTH of the Bible, and its sad that so many brothers and sisters lean on their own earthly, wicked, knowledge. But the knowledge that has been placed in my heart by our LORD, CHRIST JESUS, will and shall stand the test of time in infinity. Thank you again my brother, for using their own POOR understanding of knowledge and science against them. THANKYOU
"Absence of GOD is absence of being: how can one create;without the CREATOR?" 14/21=2/3 ~Jacob Andrew Hartman

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Posted by Claire in Scheepers @ 19:41 on Jan 7 2010

Geologists use the decay of Uranium to Lead Or Potassium to Argon to date rocks and the earth is provably well over 3 BILLION years old- Carbon dating is only used in Archeological context (with ORGANIC carbon origin and is only reliable (with error margins) to around 50 000 years.. - Any earth Scientist knows this. (Or should)

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Posted by Rick Starr in Knoxville, TN @ 00:11 on Oct 29 2009

**and certainly must be less than 57000 years old. This does not prove a biblical age of 6000 years, but it is certainly consistent with that position.**

Um, it's not vaguely consistent with that position. Even if it is "less" than 57,000 years old, it might be 51,000 years old, which is nowhere close to the 6,000 year figure Bible literalists claim. There is a lot more room for "Bzzt. WRONG" than "certainly consistent" there.

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Posted by NellyFrizzle @ 11:20 on Jul 30 2009

Carbon Dating is pretty good if you know how to use it. The major problem with carbon dating is that its based on an assumption. Assuming that the amount of C14 and C12 in the atmosphere to be in equilibrium during the time the fossil in question was alive.
Now, like summer has kindly noted, you need to know how much C14 you are starting off with in order to make any calculations on its continuing half-life count down. The only way to do this is to take into account the ratio between the stable C12 and C14 and work your way down from there. And we all know now that C12 and C14 are not in equilibrium stats... and they never were, we know what the ratio is now so carbon dating recent stuff is fairly easy...
And diamonds being pure carbon dated at the hundred of millions of years should not contain C14. The point is that all C14 should have expired and leave no trace, unless of course they are not in the millions of years age group. The "get into" impossibility means that it can't be contaminated or injected externally with C14. The only C14 in it are the ones present the day the diamond was formed. Which apparently wasn't that long ago...
As for potassium, uranium and others of the same family of unstable elements for dating, they are all built on the shoulders of assumptions. Do some research, all dating techniques spring not from a given fact, but an assumption. For example in potassium 40, it is assumed that no calcium or Argon were initially present... another assumption is that the subject was not contaminated by the half-life offspring element...now thats a tall order for something lying around for "millions" of years....

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Reply by Greg in NZ @ 08:50 on May 15 2012

I believe the following article does a pretty job at explaining the low levels of C14 found when carbon dating diamond/coal etc... http://www.asa3.org/ASA/education/origins/carbon-kb.htm
Quick question also. Have ALL diamonds that have been examined show significant C14 residues? Or are they the exception to the rule? So far I have only found 1 reference to six diamonds tested from a Namibian mine, tested and funded by a creationist group, which whilst I respect their findings is not exactly unbiased sourcing. Put another way, if examining data on drug effects in the research base, you wouldn't include research funded by a pharmaceutical group for a product they sell.
As for the other isotopic dating techniques, maybe you would care to share the links or state the articles which you feel make them suspect. That way we could all learn a bit more about it, as despite what you say, finding the credible scientific data for either side of the debate is tricky and not well laid out on either creationist or evolutionary sites.

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Reply by Jason Wreight in Melbourne @ 04:36 on Apr 15 2012

"......now thats a tall order for something lying around for "millions" of years.... "

Like dinosaur fossils, d'you mean Nelly?

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Posted by A fellow Christian in USA @ 21:32 on Jul 21 2009

Although the half-life of carbon-14 makes it unreliable for dating fossils over about 50,000 years old, there are other isotopes we use to date older artifacts. These isotopes have longer half-lives and so are found in greater abundance in older fossils.

Some of these other isotopes include:

* Potassium-40 found in your body at all times; half-life = 1.3 billion years
* Uranium-235; half-life = 704 million years
* Uranium-238; half-life = 4.5 billion years
* Thorium-232; half-life = 14 billion years
* Rubidium-87; half-life = 49 billion years

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Posted by godhammer in USA @ 09:26 on Jul 5 2009

The article's author's understanding of half-life and carbon-14 is flawed and insufficient. Please try to achieve some mastery of a scientific concept before making claims for or against it. And if you don't understand it, please don't write an article pretending that you do.

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Posted by Matthew in Melbourne @ 10:06 on Mar 19 2009

I find it amusing that some creationists attack the "half-life" while others (e.g The writers of the article on Answerswithgenisis.com) say it is a fair concept. The article gives off the impression that they agree with the carbon-14 dating process but say it is flawed by the non-constant carbon-14 to carbon12 ratio. The website actualy agrees with the half-life and radioactive decay. Are they unaware that isotopes of other radioactive elements such as Uranium-238 have a half-life of 4.47 billion years? How come creationists aren't pouncing on this? It seems unfair that Carbon-14 can be accepted because it's half-life sits in the timescale of the bible yet Uranium-238 goes unnoticed even though it's half-life is as old as the earth...

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Posted by Summer Glau in Wisconsin @ 02:04 on Feb 24 2009

Dear Sir,

Diamonds are made of pure carbon. They can have whatever kind of C they want! C-12, C-14, etc. They also have a nasty tendency to decay into graphite, but that's another story. Nothing has to "get into" a diamond to give it C-14. Diamonds come from charcoal that is millions of years old, which came from dead organisms.

If you knew anything about radioactive decay, you would know that you don't need an entire half-life to pass in order to calculate it. You only need to wait for a few particles to decay, then you can do some relatively simple math to calculate the half-life. We have proven this method to be accurate by using various other substances that have extremely short half-lives (on the order of seconds, hours, etc.)

You also seem to be confused about what a half-life is. It is a statistical measure of how long it takes for half of a given amount of a substance to decay. This is how carbon dating works -- we know how much C-14 is in something when it's "new," then we measure how much is in it now. If it's half of the "new" value, one half-life has passed. If it's 1/4 of the "new" value, two half-lives have passed, and so on.

For these reasons, Sir, I find your argument fallacious and your conclusion invalid, QED.

Please check your facts next time, maybe with a scientist. Articles like this make some people think that religious types are out to cut down anything that disagrees with their previously-held beliefs, and will ignore anything they don't like and just stick with misinformation and ignorance.

Yours &c.,

Summer Glau

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Posted by FirstLight in Boston @ 21:15 on Feb 19 2009

God or not, the lie imposed on the public who are mostly not scientists is that science can prove the age of things via carbon dating - to be millions of years old. So now the public will have to catch up with the truth of carbon dating...most non-scientific types don't have this information.

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What's the truth about carbon-dating

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