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Carbon Dating Unreliable.

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ERRORS FEARED IN CARBON DATING (NEW YORK TIMES)

Published: May 31, 1990
LEAD: Since 1947, scientists have reckoned the ages of many old objects by measuring the amounts of radioactive carbon they contain. New research shows, however, that some estimates based on carbon may have erred by thousands of years.Since 1947, scientists have reckoned the ages of many old objects by measuring the amounts of radioactive carbon they contain. New research shows, however, that some estimates based on carbon may have erred by thousands of years.

It is too soon to know whether the discovery will seriously upset the estimated dates of events like the arrival of human beings in the Western Hemisphere, scientists said. But it is already clear that the carbon method of dating will have to be recalibrated and corrected in some cases.

Scientists at the Lamont-Doherty Geological Laboratory of Columbia University at Palisades, N.Y., reported today in the British journal Nature that some estimates of age based on carbon analyses were wrong by as much as 3,500 years. They arrived at this conclusion by comparing age estimates obtained using two different methods – analysis of radioactive carbon in a sample and determination of the ratio of uranium to thorium in the sample. In some cases, the latter ratio appears to be a much more accurate gauge of age than the customary method of carbon dating, the scientists said.

In principle, any material of plant or animal origin, including textiles, wood, bones and leather, can be dated by its content of carbon 14, a radioactive form of carbon in the environment that is incorporated by all living things. Because it is radioactive, carbon 14 steadily decays into other substances. But when a plant or animal dies, it can no longer accumulate fresh carbon 14, and the supply in the organism at the time of death is gradually depleted.

Since the rate of depletion has been accurately determined (half of any given amount of carbon 14 decays in 5,730 years), scientists can calculate the time elapsed since something died from its residual carbon 14.

Dating Subject to Error

But scientists have long recognized that carbon dating is subject to error because of a variety of factors, including contamination by outside sources of carbon. Therefore they have sought ways to calibrate and correct the carbon dating method. The best gauge they have found is dendrochronology: the measurement of age by tree rings.

Accurate tree ring records of age are available for a period extending 9,000 years into the past. But the tree ring record goes no further, so scientists have sought other indicators of age against which carbon dates can be compared. One such indicator is the uranium-thorium dating method used by the Lamont-Doherty group.

Uranium 234, a radioactive element present in the environment, slowly decays to form thorium 230. Using a mass spectrometer, an instrument that accelerates streams of atoms and uses magnets to sort them out according to mass and electric charge, the group has learned to measure the ratio of uranium to thorium very precisely.

The Lamont-Doherty scientists conducted their analyses on samples of coral drilled from a reef off the island of Barbados. The samples represented animals that lived at various times during the last 30,000 years.

Uranium-Thorium Dating

Dr. Alan Zindler, a professor of geology at Columbia University who is a member of the Lamont-Doherty research group, said age estimates using the carbon dating and uranium-thorium dating differed only slightly for the period from 9,000 years ago to the present. ”But at earlier times, the carbon dates were substantially younger than the dates we estimated by uranium-thorium analysis,” he said. ”The largest deviation, 3,500 years, was obtained for samples that are about 20,000 years old.”

One reason the group believes the uranium-thorium estimates to be more accurate than carbon dating is that they produce better matches between known changes in the Earth’s orbit and changes in global glaciation.

According to carbon dating of fossil animals and plants, the spreading and receding of great ice sheets lagged behind orbital changes by several thousand years, a delay that scientists found hard to explain. But Dr. Richard G. Fairbanks, a member of the Lamont-Doherty group, said that if the dates of glaciation were determined using the uranium-thorium method, the delay – and the puzzle – disappeared.

The group theorizes that large errors in carbon dating result from fluctuations in the amount of carbon 14 in the air. Changes in the Earth’s magnetic field would change the deflection of cosmic-ray particles streaming toward the Earth from the Sun. Carbon 14 is thought to be mainly a product of bombardment of the atmosphere by cosmic rays, so cosmic ray intensity would affect the amount of carbon 14 in the environment at any given time. #30,000-Year Limit The Lamont-Doherty group says uranium-thorium dating not only is more precise than carbon dating in some cases, but also can be used to date much older objects. Carbon dating is unreliable for objects older than about 30,000 years, but uranium-thorium dating may be possible for objects up to half a million years old, Dr. Zindler said. The method is less suitable, however, for land animals and plants than for marine organisms, because uranium is plentiful in sea water but less so in most soils.

But even if the method is limited to marine organisms, it will be extremely useful for deciphering the history of Earth’s climate, ice, oceans and rocks, Dr. Fairbanks said.

 _____________________________________________________________

This is a follow up on the Carbon Dating sory from yesterday it is just that people want to claim that Kent Hovind is lying.

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Written by dawkinswatch

January 31, 2008 at 11:37 pm

11 Responses

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  1. Kent Hovind is lying, unfortunately, if he is claiming that dating errors are support for the idea of a young earth. The numbers used in the article are an error of 3,500 years for a speciman dated by other methods at 20,000 years old. Wait! Other methods?

    Yes, there are other dating methods, one of the most simple being tree-ring dating which is reliable back to 9000 years ago and alone is enough to refute Mr. Hovind’s claim of a young earth. The fascinating thing is that starting from tree rings and other things, science has built a framework to date very old things. If there is a problem with carbon dating (as with your silly repitition of the Piltdown man hoax) it will be found by science and duly publicized by science.

    This openess is in direct opposition to the way Mr. Hovind operates. He is well aware of his many factual errors, having had them explained to him in public by more learned men, yet he maintains his position in order to bilk the public in various ways. His greed is clearly evidenced by his incarceration for tax crimes.

    Hovind has also dishonestly offerred $250,000.00 to anyone that can “prove” evolution. Of course, he puts so many conditions on the deal that it is impossible and actually has nothing to do with evolution. He has also never demonstrated that he had $250,000.00 to pay a winner. He has claimed that he has but has never produced proof. I suppose it is just possible that he has no idea what “proof” means; that would explain a lot.

    Hovind is a consummate liar and whatever grain of truth there is in his rants is there only to aid his larger deception.

    Mike

    February 1, 2008 at 7:29 pm

  2. Well said, Mike.
    Hovind’s career so far is so full of lies and false arguments (as well as a number of dishonest tactics), it’s amazing that anyone listens to him at all.

    Matt

    February 6, 2008 at 12:51 am

  3. Great article. Carbon 14 dating is a sham!! It’s the biggest lie of the century… If you put a grape in the sun today it would shrivel into a raisin within days, but if you would of put a raisin in the sun a thousand years ago it would shrivelled much faster b/c of climate change. In 10 years the suns rays would be stronger than today, the sun is heating up.. this is the main cause of global warming. Any arguments would make me mention that the other planets in our solar system are also heating up, and there are no cars on mars to cause it. Science is good when you have “proof”, but Carbon 14 dating is not an effective way to know how old something is. It’s crazy to think you can date an old bone and know if it’s 3 thousand or 10 million years old b/c for example if you keep a bone out of the rain, and the sun, compared to a bone in direct line of the sun with acid rain or even under the water it may appear a bit older than the other bone.

    Jonathan

    April 13, 2008 at 7:49 am

  4. [...] Now I have shown you a number of reason why the religion called Evolution is based on a number of lies.  I have wriien a number of articles on why Carbon Dating is a mugs game. [...]

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    September 5, 2008 at 1:27 pm

  6. Out history is virtual history 621 CE – 1400 AD. It is Babylonian Dream History

    xi

    January 16, 2009 at 12:11 pm

  7. Carbon dating is unreliable for objects older than about 30,000 years, but uranium-thorium dating may be possible for objects up to half a million years old, Dr. Zindler said.

    Mike, next time, read the article. You just made a fool out of yourself….

    Anti-Mike

    July 16, 2010 at 2:05 am

  8. [...] Scientists have discovered it is not full proof. [...]

  9. There have been proven to be many flaws in carbon dating. With the opinion the the atmosphere has never changed we could depend on C14. The fact that science has proven the atmosphere has changed a few times as recorded already in the last few hundred years would prove carbon dating to be inaccurate to anyone who is non biased.

    jon

    August 3, 2013 at 12:47 am

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