If its current level is only one quarter of the original estimate, 11,460 years old, and so on. Since scientists aren’t able to take sophisticated equipment back in time to actually measure the C14 concentration when a plant or animal died, it is necessary to estimate.
It was natural for Willard Libby, the inventor of the method, to assume No doubt, he had been taught it from his youth, and he reasoned that living things in the past must have had the same C14 levels as seen in living things in modern times.
Therefore, he used modern C14 levels to approximate the ancient. Estimated years since a specimen died based on how much C14 was believed to have decayed since the death of the specimen.
For example: “Nobody cites the many hundreds of C Carbon-14 is radioactive—therefore, it decays over time.
It can be used as a dating tool because creatures and plants accumulate it during their lifetimes, and cease doing so when they die. If four essential facts are known, an age can be calculated with precision.
Indeed, experiments have led to a startling conclusion: that C14 levels in the past were lower than they are now.
If the experimental data was correctly collected and interpreted, Libby’s assumption in estimating the original content is wrong.
Measuring the current levels of C14 in a specimen is—by far—the most precisely determinable of the four essential facts.
With the advent of AMS technology, and the less-precise technique is often employed.
Early estimates of C14’s half-life ranged from 1,000 to 25,000 years.
Alasdair Beal noted a frailty in estimating the half-life: “It is worth remembering that the half-life of C14 used in the calculations (5,730 years or thereabouts) has been calculated from measurements taken over only a few decades. it would take only slight contamination to affect the result.” Although there is still some uncertainty regarding the precise decay rate of C14, perhaps a more important question is whether the decay rate is consistent over time.
The technique suggests that the specimen died about 5,730 years ago (one half-life).
Testing has not verified Libby’s assumption of uniformity.
However, “changes in radioactive decay constant depending on the physical and chemical environment of the nuclide have been known for 40 years.” In particular a researcher . As the discovery was not of direct relevance to the research involved it was not published until 1994, when it appeared to have relevance to the problem of “cold fusion.” That test involved other radioactive elements, but it showed that radioactive decay rates can be altered, thus creating more uncertainty regarding the second of the facts essential to precise C14 dates. neutrino flux of the superexplosion must have had the peculiar characteristic of resetting all our atomic clocks.” Supernova 1987-A was studied carefully by scientists.