7

Creationists make the claim that a global flood has messed up the precision of radiocarbon dating and hence, it cannot be relied upon. But if it is consistently cross-referenced by other methods, then the claim doesn't quite work.

I wonder if there were specific studies showing that let's say a supposed prehuman species dated at X years old are found surrounded by tools and rocks dated same X years old by argon-argon method or some such.


Examples of the claim:

What role might the Genesis Flood have played in the amount of carbon? The Flood would have buried large amounts of carbon from living organisms (plant and animal) to form today’s fossil fuels (coal, oil, etc.). The amount of fossil fuels indicates there must have been a vastly larger quantity of vegetation in existence prior to the Flood than exists today. This means that the biosphere just prior to the Flood might have had 500 times more carbon in living organisms than today. This would further dilute the amount of 14C and cause the 14C/12C ratio to be much smaller than today.

When the Flood is taken into account along with the decay of the magnetic field, it is reasonable to believe that the assumption of equilibrium is a false assumption.

Because of this false assumption, any age estimates using 14C prior to the Flood will give much older dates than the true age. Pre-Flood material would be dated at perhaps ten times the true age. ...

The average 14C estimated age for all the layers from these three time periods was approximately 50,000 years. However, using a more realistic pre-Flood 14C /12C ratio reduces that age to about 5,000 years. ...

An alternative interpretation of the carbon-14 data is that the earth experienced a global flood catastrophe which laid down most of the rock strata and fossils.
Answers in Genesis

AiG, a very popular Creationist website, has many other articles that say similar things.

  • 2
    can you qoute or link to what does "Great Flood has messed up the precision of radiocarbon method and hence, it cannot be relied upon." means ? it's hard to answer to general and wide arguments – Rsf Sep 28 '18 at 9:01
  • Yes, they are, but you could write books about this ;-) This question is better suited for Earth Science though, and maybe your answers are there already. I suggest you remove it here because it does not really have a notable claim – Jan Doggen Sep 28 '18 at 9:02
  • I'm new here too, but it would help if you could include a link to a specific claim. But even if there is proof, their argument appears to be "My magic renders your science wrong". Any other dating method and any other science can be denied the same way. – Jerome Viveiros Sep 28 '18 at 10:02
  • The flood messing up radiocarbon is a separate thing, I'll post the question later. – Gregory Reshetniak Sep 28 '18 at 10:50
  • I can't be bothered offering evidence... But it is the case that carbon dating... Although pretty well tested and corroborated is recognised as being imprecise. In almost no case would carbon dating alone be used to provide an accurate dating. Archaeologists use it frequently to get a rough idea of the age of things when no other method is available.. but they'll wave their hands and say 'about' 4000 years.. etc. – Richard Oct 1 '18 at 23:55
11

Carbon dating has been extensively cross-referenced by tree-ring dating (dendrochronology). Carbon dates that are corrected by tree-ring dating are called calibrated.

Tree-ring dating relies on the fact that trees have annual growth spurts and dormant period. As a result, each year the tree grows a new set of light and dark layers. These rings are easiest to see if the tree has been cut down. However, it is also possible to drill a core sample out of a living tree and inspect the rings that way.

The width of tree rings depends on the climate conditions during the year, and it is possible to match the rings of individual trees, so it is possible to create a pattern of rings that covers a much longer time span than the life of a single tree. It is possible to do this, not only with living trees, but also with trees that have died a long time ago. It's even possible to use pieces of wood that were used millennia ago, by comparing the rings with those of other trees.

As tree-ring dating is done by simple counting and comparing, it is inherently very accurate. If carbon dating is done on pieces of wood that have been dated that way, the two dates can be compared, and the C14 dating corrected as necessary. A calibration graph has been produced, going back over 40,000 years.

It should be noted that both tree-ring dating and radio carbon dating only work in the relatively recent past. For measurements of longer time periods, other methods need to be used. Some methods can be used to calibrate some of them. For example, ice cores in Antarctica have yearly layers going back about 50,000 years, and then below that dates going back hundreds of thousands of years are obtained by fitting chemical concentration history curves together between the ice core samples and other isotopic studies. For even longer time spans, there are many different isotopic age measurements, and where they overlap they can be used for cross-calibration.

In summary, while all measurements have some inherent uncertainty, these errors are in percentages. It is simply not feasible that our measurements could be wrong by a factor of more than 2 million (the difference between 6000 years and 13.8 billion years).

EDIT

A couple of comments about the additional quoted text edited into the question.

This means that the biosphere just prior to the Flood might have had 500 times more carbon in living organisms than today.

That just means they need to lump everything dating from before the flood together, in order to make the flood hypothesis work. I'd like to see a world with 500 times more living matter than the present!

The average 14C estimated age for all the layers from these three time periods was approximately 50,000 years.

C14 dating is not usable for samples older than 50000 years, as there will be no C14 left in the sample. Hence, everything older will seem to have an age of about 50000 years: zero C14. That is why different methods are used for samples that are expected to be older.

When the Flood is taken into account along with the decay of the magnetic field

That is wishful thinking. The magnetic field fluctuates over both the long and short term. Even if the current decrease continues, that may mean no more than the fact that the field is reversing again, as it has done numerous times in the past. It's another of the misrepresentations of science that are common in creationist writing.

  • 3
    Can you please refer me to any source of the claim in the last paragraph? – Gregory Reshetniak Sep 28 '18 at 10:49
  • "As tree-ring dating is done by simple counting and comparing, it is inherently very accurate." Counting is inherently accurate. Comparing is inherently subjective. What exactly are they comparing to decide two rings from different trees were grown in the same year? – fredsbend Sep 28 '18 at 14:21
  • Ice cores in Antarctica only show layers up to about 50,000 years. Beyond that they use other methods than layer-counting. – elliot svensson Sep 28 '18 at 16:46
  • For the bottom part of the core (that is, for the period older than 50 kyr), we used several age control windows derived by comparison to the stacked marine isotope curve of Bassinot3, assuming a 4-kyr phase lag. These points are situated at Terminations II (1,738 m = 131.6 kyr), III (2,311 m =245.6 kyr), IV (2,593 m =338.6 kyr), VII (3,038 m =626.6 kyr) and VIII (3,119 m =717.6 kyr). Note that the age of identical events in this EDC2 chronology can differ, over their common parts, from the Vostok and Dome Fuji chronologies, because of slightly different best-fit parameters in the model. (1/2) – elliot svensson Sep 28 '18 at 16:51
  • 1
    I removed the last paragraph as I have not been able to find a source. I'll re-add it if I find one. – hdhondt Sep 29 '18 at 4:47

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .