Shortcomings of radiocarbon dating

20-Jun-2016 13:07

Coal, oil, and natural gas are supposed to be millions of years old; yet creationists say that some of them contain measurable amounts of C-14, enough to give them C-14 ages in the tens of thousands of years. Younger objects can easily be dated, because they still emit plenty of beta radiation, enough to be measured after the background radiation has been subtracted out of the total beta radiation. However, you now know why this fact doesn't at all invalidate radiocarbon dates of objects younger than twenty thousand years and is certainly no evidence for the notion that coals and oils might be no older than fifty thousand years.

However, in either case, the background beta radiation has to be compensated for, and, in the older objects, the amount of C-14 they have left is less than the margin of error in measuring background radiation. Question: Creationists such as Cook (1966) claim that cosmic radiation is now forming C-14 in the atmosphere about one and one-third times faster than it is decaying.

For the most part, radiocarbon dating has made a huge difference for archaeologists everywhere, but the process does have a few flaws.

For example, if an object touches some organic material (like, say, your hand), it can test younger than it really is.

Thus, a freshly killed mussel has far less C-14 than a freshly killed something else, which is why the C-14 dating method makes freshwater mussels seem older than they really are.

When dating wood there is no such problem because wood gets its carbon straight from the air, complete with a full dose of C-14.

And lastly, the ratio of C-14 to C-12 in the atmosphere (and hence the ratio in organic remains) has fluctuated to a certain extent over the millennia, something that can lead to misleading discrepancies that need to be corrected for.Also, the larger the sample the better, although new techniques mean smaller samples can sometimes be tested more effectively.The data can be a little off particularly in younger artifacts, and anything older than about 50,000 years is pretty much too old to be tested because at that point the majority of the C-14 has decayed to practically undetectable levels.The excavator might employ relative dating, using objects located stratigraphically (read: buried at the same depth) close to each other, or he or she might compare historical styles to see if there were similarities to a previous find.But by using these imprecise methods, archeologists were often way off.

And lastly, the ratio of C-14 to C-12 in the atmosphere (and hence the ratio in organic remains) has fluctuated to a certain extent over the millennia, something that can lead to misleading discrepancies that need to be corrected for.Also, the larger the sample the better, although new techniques mean smaller samples can sometimes be tested more effectively.The data can be a little off particularly in younger artifacts, and anything older than about 50,000 years is pretty much too old to be tested because at that point the majority of the C-14 has decayed to practically undetectable levels.The excavator might employ relative dating, using objects located stratigraphically (read: buried at the same depth) close to each other, or he or she might compare historical styles to see if there were similarities to a previous find.But by using these imprecise methods, archeologists were often way off.But now archaeologists studying, say, the development of agriculture across the continents are able to determine how different societies stacked up against one another throughout the millennia.