Answers to Creationist Attacks on Carbon Dating | NCSE
Radiometric Dating. Geologists use radiometric dating to estimate how long ago rocks formed, and to infer the ages of fossils contained within those rocks. Download Carbon Dating Undercuts Evolution's Long Ages PDF. Evolutionists generally feel secure even in the face of compelling creationist arguments today . Radiocarbon dating, which is also known as carbon dating, . and how it relates to evolution and the age of the Earth (Uniformitarian).
This means that the tree-ring dates would be slightly too young, not too old. Of course, some species of tree tend to produce two or more growth rings per year. But other species produce scarcely any extra rings. Most of the tree-ring sequence is based on the bristlecone pine.
This tree rarely produces even a trace of an extra ring; on the contrary, a typical bristlecone pine has up to 5 percent of its rings missing. Concerning the sequence of rings derived from the bristlecone pine, Ferguson says: In the growth-ring analyses of approximately one thousand trees in the White Mountains, we have, in fact, found no more than three or four occurrences of even incipient multiple growth layers.
Hence at least some of the missing rings can be found. Even so, the missing rings are a far more serious problem than any double rings.
Other species of trees corroborate the work that Ferguson did with bristlecone pines. Before his work, the tree-ring sequence of the sequoias had been worked out back to BC. The archaeological ring sequence had been worked out back to 59 BC. The limber pine sequence had been worked out back to 25 BC.
Dating the age of humans | Feature | Chemistry World
The radiocarbon dates and tree-ring dates of these other trees agree with those Ferguson got from the bristlecone pine. But even if he had had no other trees with which to work except the bristlecone pines, that evidence alone would have allowed him to determine the tree-ring chronology back to BC.
See Renfrew for more details. So, creationists who complain about double rings in their attempts to disprove C dating are actually grasping at straws. If the Flood of Noah occurred around BC, as some creationists claim, then all the bristlecone pines would have to be less than five thousand years old. This would mean that eighty-two hundred years worth of tree rings had to form in five thousand years, which would mean that one-third of all the bristlecone pine rings would have to be extra rings.
Creationists are forced into accepting such outlandish conclusions as these in order to jam the facts of nature into the time frame upon which their "scientific" creation model is based.
Barnes has claimed that the earth's magnetic field is decaying exponentially with a half-life of fourteen hundred years. Not only does he consider this proof that the earth can be no older than ten thousand years but he also points out that a greater magnetic strength in the past would reduce C dates.
Now if the magnetic field several thousand years ago was indeed many times stronger than it is today, there would have been less cosmic radiation entering the atmosphere back then and less C would have been produced.
Therefore, any C dates taken from objects of that time period would be too high. How do you answer him? Like Cook, Barnes looks at only part of the evidence. What he ignores is the great body of archaeological and geological data showing that the strength of the magnetic field has been fluctuating up and down for thousands of years and that it has reversed polarity many times in the geological past.
So, when Barnes extrapolates ten thousand years into the past, he concludes that the magnetic field was nineteen times stronger in BC than it is today, when, actually, it was only half as intense then as now. This means that radiocarbon ages of objects from that time period will be too young, just as we saw from the bristlecone pine evidence.
But how does one know that the magnetic field has fluctuated and reversed polarity?
- Create your free account
- Answers to Creationist Attacks on Carbon-14 Dating
- Research illuminates inaccuracies in radiocarbon dating
Aren't these just excuses scientists give in order to neutralize Barnes's claims? The evidence for fluctuations and reversals of the magnetic field is quite solid. Bucha, a Czech geophysicist, has used archaeological artifacts made of baked clay to determine the strength of the earth's magnetic field when they were manufactured.
He found that the earth's magnetic field was 1. See Bailey, Renfrew, and Encyclopedia Britannica for details. In other words, it rose in intensity from 0. Even before the bristlecone pine calibration of C dating was worked out by Ferguson, Bucha predicted that this change in the magnetic field would make radiocarbon dates too young. This idea [that the fluctuating magnetic field affects influx of cosmic rays, which in turn affects C formation rates] has been taken up by the Czech geophysicist, V.How Carbon Dating Works
Bucha, who has been able to determine, using samples of baked clay from archeological sites, what the intensity of the earth's magnetic field was at the time in question. Even before the tree-ring calibration data were available to them, he and the archeologist, Evzen Neustupny, were able to suggest how much this would affect the radiocarbon dates.
There is a good correlation between the strength of the earth's magnetic field as determined by Bucha and the deviation of the atmospheric radiocarbon concentration from its normal value as indicated by the tree-ring radiocarbon work.
As for the question of polarity reversals, plate tectonics can teach us much.
Radiocarbon dating - Wikipedia
It is a fact that new oceanic crust continually forms at the mid-oceanic ridges and spreads away from those ridges in opposite directions. When lava at the ridges hardens, it keeps a trace of the magnetism of the earth's magnetic field. Therefore, every time the magnetic field reverses itself, bands of paleomagnetism of reversed polarity show up on the ocean floor alternated with bands of normal polarity.
These bands are thousands of kilometers long, they vary in width, they lie parallel, and the bands on either side of any given ridge form mirror images of each other. Thus it can be demonstrated that the magnetic field of the earth has reversed itself dozens of times throughout earth history. Barnes, writing inought to have known better than to quote the gropings and guesses of authors of the early sixties in an effort to debunk magnetic reversals.
Before plate tectonics and continental drift became established in the mid-sixties, the known evidence for magnetic reversals was rather scanty, and geophysicists often tried to invent ingenious mechanisms with which to account for this evidence rather than believe in magnetic reversals.
However, bysea floor spreading and magnetic reversals had been documented to the satisfaction of almost the entire scientific community. Yet, instead of seriously attempting to rebut them with up-to-date evidence, Barnes merely quoted the old guesses of authors who wrote before the facts were known.
But, in spite of Barnes, paleomagnetism on the sea floor conclusively proves that the magnetic field of the earth oscillates in waves and even reverses itself on occasion. It has not been decaying exponentially as Barnes maintains.
Does outside archaeological evidence confirm theC dating method? When we know the age of a sample through archaeology or historical sources, the C method as corrected by bristlecone pines agrees with the age within the known margin of error. For instance, Egyptian artifacts can be dated both historically and by radiocarbon, and the results agree. At first, archaeologists used to complain that the C method must be wrong, because it conflicted with well-established archaeological dates; but, as Renfrew has detailed, the archaeological dates were often based on false assumptions.
One such assumption was that the megalith builders of western Europe learned the idea of megaliths from the Near-Eastern civilizations. As a result, archaeologists believed that the Western megalith-building cultures had to be younger than the Near Eastern civilizations. Many archaeologists were skeptical when Ferguson's calibration with bristlecone pines was first published, because, according to his method, radiocarbon dates of the Western megaliths showed them to be much older than their Near-Eastern counterparts.
Since only uranium, and not thorium, is present at sample formation, comparing the two ratios can be used to calculate the time passed since the sample formed. They found it was at least 37, years old. It also unleashed another mystery. Anatomically modern humans arrived in northern Spain around 42, to 43, years ago, and Neanderthals died out between 39, and 41, years ago. For some, it fits in with emerging evidence that Neanderthals were an intelligent human species, but others remain unconvinced.
Regardless, if there is evidence to find that Neanderthals were artists, dating will be the thing to expose it. Shining a light on technology Like we recognise art as quintessentially human, we also consider tool use and technological progress to be defining for our species, and it was as important to ancient humans as it is to us.
However, to discover how tool use relates to human evolution, scientists must be able to date it. In sediments there are radioactive isotopes that send out ionising radiation, which is absorbed by surrounding quartz, exciting some of its electrons.
In the lab, a buried sample can then be optically stimulated to release the electrons and cause a luminescence signal with an intensity that depends on the absorbed radiation dose. It is therefore possible to calculate the burial time of the sample using the total radiation dose and rate. According to Walker, OSL was a really exciting development when it was first discovered. And this became a problem for some of the older sediments.
Duller and his team therefore had to come up with a way to extend its application to get a full chronology. For Kalambo Falls, however, this was enough — the site now has a chronology of its artefacts that, despite large error bars, has given it the scientific authority it deserved in the discussion of human technological progress.
Dating in an eggshell Rigorous refinement of dating methods, like the development of TT-OSL, has been necessary to tackle the new problems that constantly arise.
This also holds true for amino acid racemisation dating AAR. Because they make their way towards equilibrium at a known rate, the ratio between d and l configurations can be used to determine when the organism died. So what was the problem? This destroys contamination and any unprotected proteins, effectively leaving a closed system.