By Griffon , December 29, in Physics. I've been poking about on the internet again as you do and found a whole load of stuff by creationists about the problems with carbon 14 radiometric dating. Specifically they report with some glee that coal has been found to contain measurable amounts of carbon14 which it should not of course because it is about million years old and dates from the carboniferous period. C14 has a half life of years and is only good to date objects to 50, years or so. Although I can find any number of references to this seemingly vital finding on the creationist sites, I can find almost no attempt to refute or explain this anomaly on serious science sites.
PZ Myers says they've had some technical issues. I am working my way through Kirk Bertsche's 9 page essay on the subject. Thanks DH for this link.
This article does a good job at explaining the technical complexities of measuring the very small amounts of C14 present in these ancient samples and why non-zero amounts are measured. I'm a complete non-expert in this field of radiometric dating, but it strikes me reading this how contamination by modern carbon introduced during sample preparation seems to be a severe issue.
I'm wonder whether they've extracted samples under an inert atmosphere and then used laser ablation to ionize samples in their mass spectrometers? I'm probably teaching grandmother to suck eggs, as the old saying goes. Getting back to my OP - I feel that some definitive work needs to be done in this area. It's easy to see that the sceptical creationist is simply going to see the scientific response as making excuses for the data instead of holding up some hard data that either explains or explodes the anomaly.
Another thing I've heard from creationists is that fossils made by soaking samples in tar pits appear to be extremely old.
Of course, the problem is that this process results in contamination with old carbon, making the sample appear older. In the case of old samples with almost no C, even the tiniest bit of contamination would make the sample appear far younger.
Always remember that C dating is not a magical process; it is a measure of C and the age interpretation depends on a few assumptions. It's also worth noting that C is only useful for a bit more thanyears. The vast majority of fossils aren't dated using C at all, but other radioisotopes.
Science has several very reasonable explanations for levels of modern carbon in very old samples. Although this satisfies the scientist, who for all sorts of other reasons quite reasonably assumes that these samples are truly old, it leaves enormous scope for the creationists to reinforce their followers' faith that the earth is young. I still feel that some definitive experiments in this area would be useful to test the various rational explanations for the c14 anomaly.
I can see though that science has problems taking on creationists because of the perceived risk of lending credibility to their ideas.
Bit of a dilemma there.
Also as soon as one creationist idea is exploded, they just move on to another area where uncertainty in the science offers them the opportunity to mislead. That begs the question that an anomaly even exists. What does exist are limits to the applicability of 14 C dating techniques. Several of the test results touted by creationists were definitive experiments to assess those limitations.
There is no arguing with young earth creationists. They are immune to logic and evidence.
Broadly speaking I agree with you. But, reading the experts' explanations of the "anomaly" read to me, as a non-expert in this field, like perfectly reasonable explanations as long as you accept the "old earth" explanation.
If you don't, such dismissive arguments as 'the extra C14 could be due to uranium decay' leave enough wriggle room uncertainty for the creationist to thrive in. You're right though, I'm probably being naive in thnking they will be convinced. Even so, it is always good when creationists have been casting doubt in some area to be able to completely explode their reasoning. I'm still looking for a reference, in a refereed scientific journal, confirming the finding of carbon14, in any amount, in diamonds or coal.
I suspect, but haven't been able to confirm, that the reports of carbon 14 in these substances have been made up out of whole cloth by Young Earth Creationists, but I am loath to make this claim, absent evidence that reports of these findings haven't been published in any journals that aren't connected with such organizations as the Institute for Creation Science.
I further think that it is the fact that the claims are conscpicuously bogus that has accounted for their not having been responded to. After all, to my limited understanding, carbon 14 is associated with organic processes, and, right off the bat, I find myself wondering why it would be found in any allotrope of carbon, which is an inorganic element.
Apr 03, You should put "most" in front of "geologists," as I have spoken to one Ph.D. geologist who says she would be a young-earth geologist if it weren't for radiometric dating. Yes, there are other issues at play (as is the case with any over-arching scientific idea), but to her, radiometric dating is the most important reason she believes. For many people, radiometric dating might be the one scientific technique that most blatantly seems to challenge the Bible's record of recent creation. For this reason, ICR research has long focused on the science behind these dating techniques. Jan 23, Uranium-lead radioisotope dating is now the preferred absolute dating method among geochronologists. Consequently, the scientific community and the general public around the world appear convinced of the earth's claimed great antiquity. But there are several problems with this particular radiometric dating jankossencontemporary.com: Troy Lacey.
Can anyone out there either confirm or disconfirm my suspicions? You need to know that I will not be much impressed by anything coming from the ICR or any similar group.
Well one of two things could be happening, the carbon 14 signature is reset every time the rock melts because the carbon 14 disperses among the liquid rock, Also neutron bombardment from uranium decay could possibly have an impact, but you'd also have other trace elements that tell the tale of this neutron contamination. The presence of carbon C in specimens that are supposedly millions of years old is a serious problem for believers in an old earth.
Carbon 14 Dating Problems - Nuclear Chemistry & Radioactive Decay
A straightforward reading of the Bible describes a 6,year-old We offered four reasons why radioisotope dating Russell Humphreys reported that helium diffusion from zircons in borehole GT-2 at Fenton Since such isotopes are thought to decay at consistent rates over time, the assumption Three geologists have reported what they called the first "successful" direct dating of dinosaur bone.
Will this new radioisotope dating or radiodating technique solve the problems that plagued older A trio of geologists has published what they called the first successful direct dating of dinosaur bone. They used a new laser technique to measure radioisotopes in the bone, yielding an age of millions Most estimates For a Radioactive Decay Rates Not Stable.
They helped underpin belief in vast ages and Radiocarbon in 'Ancient' Fossil Wood.
A Tale of Two Hourglasses. In your kitchen you start a three-minute egg timer and a minute hourglass simultaneously and then leave. You return a short while later to find the hourglass fully discharged but not the egg timer! Confirmation of Rapid Metamorphism of Rocks. Where thick sequences of sedimentary rock layers have been deposited in large basins, the deepest layers at the bottoms of the sequences may subsequently have become folded by earth movements when subjected Deep inside the Inner Gorge of Grand Canyon, northern Arizona, are the crystalline basement rocks that probably date back even to the Creation Week itself.
Clearly visible in the canyon walls are the Evolutionists generally feel secure even in the face of compelling creationist arguments today because of their utter confidence in the geological time scale.
Even if they cannot provide a naturalistic Two years ago it was reported that polonium Po radiohalos were still "a very tiny mystery. Investigating Polonium Radiohalo Occurrences. The procedures used to isolate and analyze the parent and daughter nuclides must be precise and accurate. This normally involves isotope-ratio mass spectrometry. The precision of a dating method depends in part on the half-life of the radioactive isotope involved. For instance, carbon has a half-life of 5, years.
After an organism has been dead for 60, years, so little carbon is left that accurate dating cannot be established. On the other hand, the concentration of carbon falls off so steeply that the age of relatively young remains can be determined precisely to within a few decades. The closure temperature or blocking temperature represents the temperature below which the mineral is a closed system for the studied isotopes. If a material that selectively rejects the daughter nuclide is heated above this temperature, any daughter nuclides that have been accumulated over time will be lost through diffusionresetting the isotopic "clock" to zero.
As the mineral cools, the crystal structure begins to form and diffusion of isotopes is less easy. At a certain temperature, the crystal structure has formed sufficiently to prevent diffusion of isotopes.
Thus an igneous or metamorphic rock or melt, which is slowly cooling, does not begin to exhibit measurable radioactive decay until it cools below the closure temperature.
The age that can be calculated by radiometric dating is thus the time at which the rock or mineral cooled to closure temperature. These temperatures are experimentally determined in the lab by artificially resetting sample minerals using a high-temperature furnace.
This field is known as thermochronology or thermochronometry. The mathematical expression that relates radioactive decay to geologic time is  . The equation is most conveniently expressed in terms of the measured quantity N t rather than the constant initial value N o. The above equation makes use of information on the composition of parent and daughter isotopes at the time the material being tested cooled below its closure temperature.
This is well-established for most isotopic systems.
An isochron plot is used to solve the age equation graphically and calculate the age of the sample and the original composition. Radiometric dating has been carried out since when it was invented by Ernest Rutherford as a method by which one might determine the age of the Earth.
In the century since then the techniques have been greatly improved and expanded. The mass spectrometer was invented in the s and began to be used in radiometric dating in the s. It operates by generating a beam of ionized atoms from the sample under test.
The ions then travel through a magnetic field, which diverts them into different sampling sensors, known as " Faraday cups ", depending on their mass and level of ionization. On impact in the cups, the ions set up a very weak current that can be measured to determine the rate of impacts and the relative concentrations of different atoms in the beams. Uranium-lead radiometric dating involves using uranium or uranium to date a substance's absolute age.
This scheme has been refined to the point that the error margin in dates of rocks can be as low as less than two million years in two-and-a-half billion years. Uranium-lead dating is often performed on the mineral zircon ZrSiO 4though it can be used on other materials, such as baddeleyiteas well as monazite see: monazite geochronology.
Zircon has a very high closure temperature, is resistant to mechanical weathering and is very chemically inert. Zircon also forms multiple crystal layers during metamorphic events, which each may record an isotopic age of the event. One of its great advantages is that any sample provides two clocks, one based on uranium's decay to lead with a half-life of about million years, and one based on uranium's decay to lead with a half-life of about 4.
This can be seen in the concordia diagram, where the samples plot along an errorchron straight line which intersects the concordia curve at the age of the sample. This involves the alpha decay of Sm to Nd with a half-life of 1. Accuracy levels of within twenty million years in ages of two-and-a-half billion years are achievable.
This involves electron capture or positron decay of potassium to argon Potassium has a half-life of 1. This is based on the beta decay of rubidium to strontiumwith a half-life of 50 billion years.
One problem with radiometric dating is
This scheme is used to date old igneous and metamorphic rocksand has also been used to date lunar samples. Closure temperatures are so high that they are not a concern. Rubidium-strontium dating is not as precise as the uranium-lead method, with errors of 30 to 50 million years for a 3-billion-year-old sample.
Application of in situ analysis Laser-Ablation ICP-MS within single mineral grains in faults have shown that the Rb-Sr method can be used to decipher episodes of fault movement.
Oct 01, Radiometric Dating PART 1: Back to Basics. PART 2: Problems with the Assumptions. PART 3: Making Sense of the Patterns. This three-part series will help you properly understand radiometric dating, the assumptions that lead to inaccurate dates, and the clues about what really happened in the jankossencontemporary.com: Dr. Andrew A. Snelling. One problem with radiometric dating is: Open-system behavior. Which method would a geologist use to date a fossil bone fragment of a mammoth? Carbon Moon rocks are: Evidence that Earth's age is approximately billion years. Which of the following statements is true? Feb 17, Ive been poking about on the internet again (as you do) and found a whole load of stuff by creationists about the problems with carbon 14 radiometric dating. Specifically they report (with some glee) that coal has been found to contain measurable amounts of carbon14 which it should not of course.
A relatively short-range dating technique is based on the decay of uranium into thorium, a substance with a half-life of about 80, years. It is accompanied by a sister process, in which uranium decays into protactinium, which has a half-life of 32, years.
While uranium is water-soluble, thorium and protactinium are not, and so they are selectively precipitated into ocean-floor sedimentsfrom which their ratios are measured. The scheme has a range of several hundred thousand years.
A related method is ionium-thorium datingwhich measures the ratio of ionium thorium to thorium in ocean sediment. Radiocarbon dating is also simply called carbon dating.
Carbon is a radioactive isotope of carbon, with a half-life of 5, years   which is very short compared with the above isotopesand decays into nitrogen. Carbon, though, is continuously created through collisions of neutrons generated by cosmic rays with nitrogen in the upper atmosphere and thus remains at a near-constant level on Earth.
The carbon ends up as a trace component in atmospheric carbon dioxide CO 2. A carbon-based life form acquires carbon during its lifetime. Plants acquire it through photosynthesisand animals acquire it from consumption of plants and other animals. When an organism dies, it ceases to take in new carbon, and the existing isotope decays with a characteristic half-life years. The proportion of carbon left when the remains of the organism are examined provides an indication of the time elapsed since its death.
This makes carbon an ideal dating method to date the age of bones or the remains of an organism. The carbon dating limit lies around 58, to 62, years.
The rate of creation of carbon appears to be roughly constant, as cross-checks of carbon dating with other dating methods show it gives consistent results. However, local eruptions of volcanoes or other events that give off large amounts of carbon dioxide can reduce local concentrations of carbon and give inaccurate dates.
The releases of carbon dioxide into the biosphere as a consequence of industrialization have also depressed the proportion of carbon by a few percent; conversely, the amount of carbon was increased by above-ground nuclear bomb tests that were conducted into the early s.
Also, an increase in the solar wind or the Earth's magnetic field above the current value would depress the amount of carbon created in the atmosphere. This involves inspection of a polished slice of a material to determine the density of "track" markings left in it by the spontaneous fission of uranium impurities.
The uranium content of the sample has to be known, but that can be determined by placing a plastic film over the polished slice of the material, and bombarding it with slow neutrons. This causes induced fission of U, as opposed to the spontaneous fission of U. The fission tracks produced by this process are recorded in the plastic film. The uranium content of the material can then be calculated from the number of tracks and the neutron flux. This scheme has application over a wide range of geologic dates.
For dates up to a few million years micastektites glass fragments from volcanic eruptionsand meteorites are best used. Older materials can be dated using zirconapatitetitaniteepidote and garnet which have a variable amount of uranium content. The technique has potential applications for detailing the thermal history of a deposit. The residence time of 36 Cl in the atmosphere is about 1 week. Thus, as an event marker of s water in soil and ground water, 36 Cl is also useful for dating waters less than 50 years before the present.
Luminescence dating methods are not radiometric dating methods in that they do not rely on abundances of isotopes to calculate age. Instead, they are a consequence of background radiation on certain minerals. Over time, ionizing radiation is absorbed by mineral grains in sediments and archaeological materials such as quartz and potassium feldspar.